US20010010473A1 - Frequency multiplier capable of taking out efficiently and stably harmonics higher than fourth order - Google Patents
Frequency multiplier capable of taking out efficiently and stably harmonics higher than fourth order Download PDFInfo
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- US20010010473A1 US20010010473A1 US09/758,366 US75836601A US2001010473A1 US 20010010473 A1 US20010010473 A1 US 20010010473A1 US 75836601 A US75836601 A US 75836601A US 2001010473 A1 US2001010473 A1 US 2001010473A1
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
- H03B19/00—Generation of oscillations by non-regenerative frequency multiplication or division of a signal from a separate source
- H03B19/06—Generation of oscillations by non-regenerative frequency multiplication or division of a signal from a separate source by means of discharge device or semiconductor device with more than two electrodes
- H03B19/14—Generation of oscillations by non-regenerative frequency multiplication or division of a signal from a separate source by means of discharge device or semiconductor device with more than two electrodes by means of a semiconductor device
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- the present invention relates to a frequency multiplier to be used as a high-stability, low-noise signal source for microwave and millimeter-wave communication systems.
- This frequency multiplier as a doubler is shown in “Monolithic Microwave Integrated Circuits (edited by the Institute of Electronics, Information and Communication Engineers), pp. 125-127”.
- This frequency multiplier as shown in FIG. 7, comprises an input-side matching circuit 101 , an FET (Field Effect Transistor) 102 , a transmission line 103 , an end-open stub 104 , and an output-side matching circuit 105 .
- the length of the end-open stub 104 is selected so as to be an electrical length of 90° with respect to the fundamental wave of the input signal, the connecting point of the end-open stub 104 is short-circuited to the input signal fundamental wave and appears open to the doubled wave, so that fundamental-wave components are suppressed and the doubled wave is outputted.
- This frequency multiplier has an additional amplification effect by the FET 102 so that a high-efficiency frequency multiplication can be achieved.
- This frequency multiplier as a quadrupler comprises an input-side matching circuit 201 , a transmission line 202 , an end-open stub 203 having an electrical length of 90° with respect to the doubled wave, an end-open stub 204 having an electrical length of 90° with respect to the quadrupled wave, an HEMT (High Electron Mobility Transistor) 205 , a transmission line 206 , an end-open stub 207 having an electrical length of 90° with respect to the doubled wave, an end-open stub 208 having an electrical length of 90° with respect to the fundamental wave, and an output-side matching circuit 209 .
- HEMT High Electron Mobility Transistor
- end-open stub 208 having an electrical length of 90° with respect to the fundamental wave and the end-open stub 207 having an electrical length of 90° with respect to the doubled wave are connected to the circuit on the drain side of the HEMT 205 , there appears no signals of the fundamental wave (frequency f 0 ) and the doubled wave (frequency 2 f 0 ). These end-open stubs are open to the signal of the quadrupled wave (frequency 4 f 0 ), so that the signal of the quadrupled wave is outputted.
- end-open stub 203 having an electrical length of 90° with respect to the doubled wave and the end-open stub 204 having an electrical length of 90° with respect to the quadrupled wave are connected to the input side, signals of the doubled wave (frequency 2 f 0 ) and the quadrupled wave (frequency 4 f 0 ) reflected from the HEMT 205 toward the input side are suppressed.
- the drain current of the FETs (including HEMTs) generally exhibits a square characteristic to the gate voltage. This causes a problem of poor efficiency at the time when harmonics of tripled wave or higher-ordered waves are taken out.
- an object of the present invention is to provide a frequency multiplier which is capable of taking out fourth- or higher-ordered harmonics efficiently with a simple constitution using one high frequency transistor, and which can be reduced in size and stabilized in operation.
- a frequency multiplier comprising:
- a high frequency transistor with base or gate connected to an output terminal of the input-side matching circuit and with emitter or source grounded;
- first signal transmission means with one end connected to collector or drain of the high frequency transistor
- doubled-wave reflection means with one end connected to the other end of the first signal transmission means
- second signal transmission means with one end connected to the other end of the first signal transmission means
- fundamental-wave reflection means with one end connected to the other end of the second signal transmission means
- the first signal transmission means is a first transmission line
- the second signal transmission means is a second transmission line
- the doubled-wave reflection means is an end-open stub for blocking passage of a doubled wave
- the fundamental-wave reflection means is an end-open stub for blocking passage of a fundamental wave.
- the collector current of the high frequency transistor increases exponentially relative to the base voltage, so that many harmonics are outputted. Then, because a short-circuit to the fundamental wave is formed at the connecting point of the end-open stub for blocking the passage of the fundamental wave, the fundamental wave is reflected toward the high frequency transistor. Also, because a short-circuit to the doubled wave is formed at the connecting point of the end-open stub for blocking the passage of the doubled wave, the doubled wave is reflected toward the high frequency transistor.
- the base of the high frequency transistor e.g., bipolar transistor
- the electrical lengths of the first transmission line and the second transmission line are optimized to, for example, about 10-40° with respect to the fundamental wave, by which the output efficiency of the quadrupled wave is increased.
- the characteristic impedances of the end-open stub for blocking the passage of the doubled wave and the end-open stub for blocking the passage of the fundamental wave to, for example, about 20-70 ⁇ , the doubled wave can be effectively suppressed without narrowing the frequency band of the quadrupled wave.
- the frequency multiplier is capable of taking out fourth- or higher-ordered harmonics efficiently with a simple constitution using one high frequency transistor, particularly taking out the quadrupled wave with high output efficiency.
- similar effects can be obtained also by using as the high frequency transistor a MESFET (MEtal Semiconductor Field Effect Transistor) or HEMT (High Electron Mobility Transistor) or the like.
- the first signal transmission means is a first inductor
- the second signal transmission means is a second inductor
- the doubled-wave reflection means is a circuit generally equivalent to an end-open stub for blocking passage of a doubled wave, the circuit being an equivalent circuit for blocking passage of the doubled wave and being constituted by a concentrated constant circuit using an inductor and a capacitor;
- the fundamental-wave reflection means is a circuit generally equivalent to an end-open stub for blocking passage of a fundamental wave, the circuit being an equivalent circuit for blocking passage of the fundamental wave and being constituted by a concentrated constant circuit using an inductor and a capacitor.
- the fundamental wave is reflected toward the high frequency transistor by the equivalent circuit for blocking the passage of the fundamental wave, so that the output power of the doubled wave is increased by the multiplying effect of the high frequency transistor.
- the doubled wave of increased output power is further reflected toward the high frequency transistor by the equivalent circuit for blocking the passage of the doubled wave, so that the output power of the quadrupled wave is further increased by the multiplying effect of the high frequency transistor.
- the reactances of the first inductor and the second inductor are optimized, by which the output efficiency of the quadrupled wave is increased.
- the frequency multiplier is capable of taking out fourth- or higher-ordered harmonics efficiently with a simple constitution using one high frequency transistor, particularly taking out the quadrupled wave with high output efficiency.
- the inductors are implemented by chip inductors or spiral inductors and the capacitors are implemented by chip capacitors or MIM capacitors, and when the distributed constant circuits of the end-open stubs are replaced with concentrated constant circuits using inductors and capacitors, the circuit occupancy area can be reduced.
- effects can be obtained when an MMIC is implemented by using spiral inductors and MIM capacitors.
- similar effects can be obtained also by using as the high frequency transistor a MESFET or HEMT or the like.
- the emitter or the source of the high frequency transistor is grounded via a transmission line.
- this frequency multiplier by inserting a transmission line between the emitter (or source) of the high frequency transistor and the ground, the reflection coefficient on the input side of the high frequency transistor can be reduced, so that the input-side matching can be easily attained without significantly losing the multiplication gain. As a result of this, the reflection characteristics at the input end of this frequency multiplier can be improved and the circuit operation can be stabilized.
- the electrical length of the transmission line is preferably 1-15° with respect to the fundamental wave.
- the emitter or the source of the high frequency transistor is grounded via an inductor.
- this frequency multiplier by inserting an inductor between the emitter (or source) of the high frequency transistor and the ground, the reflection coefficient on the input side of the high frequency transistor can be reduced, so that the input-side matching can be easily attained without significantly losing the multiplication gain. As a result of this, the reflection characteristics at the input end of this frequency multiplier can be improved and the circuit operation can be stabilized.
- the reactance of the inductor is preferably 1- 10 ⁇ with respect to the fundamental wave.
- the high frequency transistor is a heterojunction bipolar transistor.
- the frequency multiplier in a comparison between the harmonic output characteristics of the HBT (Heterojunction Bipolar Transistor) and another high frequency transistor, for example, an HEMT, which are operated at around the pinch-off, the difference between fundamental wave and doubled wave is similar in level to each other, whereas the output power ratio of third- or higher-ordered harmonics is higher in the HBT than the HEMT.
- the output power of harmonics can be increased by employing the HBT as the high frequency transistor.
- FIG. 1 is a circuit diagram of a frequency multiplier according to a first embodiment of the present invention
- FIG. 2 is a circuit diagram of a frequency multiplier according to a second embodiment of the present invention.
- FIG. 3 is a circuit diagram of a frequency multiplier according to a third embodiment of the present invention.
- FIG. 4 is a circuit diagram of a frequency multiplier according to a fourth embodiment of the present invention.
- FIG. 5 is a chart showing harmonic output characteristics at the pinch-off of the HBT
- FIG. 6 is a chart showing harmonic output characteristics at the pinch-off of the HEMT
- FIG. 7 is a circuit diagram showing a frequency multiplier serving as a doubler according to the prior art.
- FIG. 8 is a circuit diagram showing a frequency multiplier serving as a quadrupler according to the prior art.
- FIG. 1 is a circuit diagram of a frequency multiplier according to a first embodiment of the present invention.
- Reference numeral 1 denotes an input-side matching circuit to which an input signal with frequency f0 is inputted
- 2 denotes an HBT (Heterojunction Bipolar Transistor) in which an output terminal of the input-side matching circuit 1 is connected to the base, and in which the emitter is connected to the ground GND
- 3 denotes a first transmission line with one end connected to the collector of the HBT 2
- 4 denotes an end-open stub for blocking the passage of the doubled wave, one end of the end-open stub 4 being connected to the other end of the first transmission line 3 , and the electrical length of the end-open stub 4 being 90° with respect to the doubled wave
- 5 denotes a second transmission line with one end connected to the other end of the first transmission line 3
- 6 denotes an end-open stub for blocking the passage of the fundamental wave, one end of the end-open
- the input-side matching circuit 1 serves for matching on the input side of the HBT 2 at the fundamental wave frequency f 0
- the output-side matching circuit 7 serves for matching on the output side of the HBT 2 at the quadrupled wave frequency 4 f 0
- the matching circuits 1 , 7 serve also as bias circuits, where the bias is set so that the HBT 2 operates at around the pinch-off.
- an input signal with frequency f0 is inputted to the base of the HBT 2 via the input-side matching circuit 1 . Because the collector current of the HBT 2 increases exponentially relative to the base voltage, many harmonics are outputted. Then, the connecting point of the end-open stub 6 for blocking the passage of the fundamental wave with the electrical length of 90° to the fundamental wave (frequency f 0 ) is short-circuited to the fundamental wave (frequency f 0 ), so that the fundamental wave is reflected toward the HBT 2 .
- the connecting point of the end-open stub 4 for blocking the passage of the doubled wave with the electrical length of 90° to the doubled wave (frequency 2 f 0 ) is short-circuited to the doubled wave, so that the doubled wave is reflected toward the HBT 2 .
- the matching circuit 7 only fourth- or higher-ordered harmonics are outputted via the matching circuit 7 .
- the characteristic impedance Zc 1 of the end-open stub 6 for blocking the passage of the fundamental wave and the characteristic impedance Zc 2 of the end-open stub 4 for blocking the passage of the doubled wave are small, the frequency band becomes wider but the suppression ratio of the fundamental wave (frequency f 0 ) and the doubled wave (frequency 2 f 0 ) becomes smaller.
- the characteristic impedances Zc 1 and Zc 2 are large, the suppression ratio of the fundamental wave (frequency f 0 ) and the doubled wave (frequency 2 f 0 ) becomes larger but the frequency band becomes narrower. That is, the suppression of the doubled wave (frequency 2 f 0 ) and the frequency band are in a trade-off relation, and normally the characteristic impedances Zc 1 and zc 2 are selected within a range of 20-70 ⁇ .
- the fundamental wave is reflected toward the HBT 2 by the end-open stub 6 for blocking the passage of the fundamental wave with the electrical length of 90° to the fundamental wave (frequency f 0 )
- the output power of the doubled wave (frequency 2 f 0 ) is increased by the multiplying effect of the HBT 2 .
- the doubled wave of increased output power is reflected toward the HBT 2 by the end-open stub 4 for blocking the passage of the doubled wave with the electrical length of 90° to the doubled wave, so that the output power of the quadrupled wave is further increased by the multiplying effect of the HBT 2 .
- the output power of the quadrupled wave becomes a maximum at their electrical lengths of 10-40° to the fundamental wave, respectively.
- the end-open stub 4 for blocking the passage of the doubled wave, the end-open stub 6 for blocking the passage of the fundamental wave and the transmission lines 3 , 5 are implemented by microstrip lines or coplanar lines or the like.
- this frequency multiplier is capable of taking out fourth- or higher-ordered harmonics with a simple constitution using one HBT and, in particular, taking out the quadrupled wave with high output efficiency.
- the collector current of the HBT used in this first embodiment increases exponentially relative to the base voltage. Accordingly, when the HBT is operated at around the pinch-off, the output power of third- or higher-ordered harmonics becomes larger as compared with the FET.
- FIG. 5 shows harmonic output characteristics at the pinch-off of the HBT
- FIG. 6 shows harmonic output characteristics at the pinch-off of the HEMT.
- Both HBT and HEMT are devices having a maximum frequency fmax of 60-70 GHz and a rated current of about 40 mA. As shown in FIGS.
- FIG. 2 is a circuit diagram of a frequency multiplier according to a second embodiment of the present invention.
- Reference numeral 11 denotes an input-side matching circuit to which an input signal with frequency f0 is inputted
- 12 denotes an HBT in which an output terminal of the input-side matching circuit 11 is connected to the base, and in which the emitter is connected to the ground GND
- 13 denotes a first inductor with one end connected to the collector of the HBT 12
- 14 denotes an inductor with one end connected to the other end of the first inductor 13
- 15 denotes a capacitor connected between one end of the inductor 14 and the ground GND
- 16 denotes a capacitor connected between the other end of the inductor 14 and the ground GND
- 17 denotes a second inductor with one end connected to the other end of the first inductor 13
- 18 denotes an inductor with one end connected to the other end of the inductor 17
- 19 denotes a capacitor connected between
- the input-side matching circuit 11 serves for matching on the input side of the HBT 12 at the fundamental wave frequency f 0
- the output-side matching circuit 21 serves for matching on the output side of the HBT 12 at the quadrupled wave frequency 4 f 0
- the matching circuits 11 , 21 serve also as bias circuits, where the bias is set so that the HBT 12 operates at around the pinch-off.
- the characteristic impedance of the end-open stub 6 for blocking the passage of the fundamental wave is Zc 1 and the characteristic impedance of the end-open stub 4 for blocking the passage of the doubled wave is Zc 2
- the inductances of the inductors 18 , 14 are L 1 , L 2 , respectively
- the capacitance of the capacitors 19 , 20 is C 1
- the capacitance of the capacitors 15 , 16 is C 2
- the first inductor 13 is used instead of the first transmission line 3 of FIG. 1, and the second inductor 17 is used instead of the second transmission line 5 of FIG. 1.
- the optimum reactance of the first, second inductors 13 , 17 varies depending on the frequency or the HBT used, the output power of the quadrupled wave becomes a maximum when the reactance of the first inductor 13 is 10-40 ⁇ with respect to the fundamental wave and the reactance of the second inductor 17 is 10-40 ⁇ with respect to the fundamental wave.
- the frequency multiplier of this second embodiment has the same effects as the frequency multiplier of the first embodiment.
- the inductors 13 , 14 , 17 , 18 are implemented by chip inductors or spiral inductors and the capacitors 15 , 16 , 19 , 20 are implemented by chip capacitors or MIM (Metal Insulator Metal) capacitors, and when the distributed constant circuits of the end-open stubs are replaced with concentrated constant circuits using inductors and capacitors, the circuit occupancy area can be reduced.
- MMIC Monitoring Microwave Integrated Circuit
- the replacement of the distributed constant circuits of the end-open stub 6 for blocking the passage of the fundamental wave and the end-open stub 4 for blocking the passage of the doubled wave with the concentrated constant circuits is effective for circuits of up to about 10 GHz.
- FIG. 3 is a circuit diagram of a frequency multiplier according to a third embodiment of the present invention.
- Reference numeral 31 denotes an input-side matching circuit to which an input signal with frequency f0 is inputted
- 32 denotes an HBT in which an output terminal of the input-side matching circuit 31 is connected to the base
- 33 denotes a transmission line for connecting the emitter of the HBT 32 and the ground GND to each other
- 34 denotes a first transmission line with one end connected to the collector of the HBT 32
- 35 denotes an end-open stub for blocking the passage of the doubled wave, one end of the end-open stub 35 being connected to the other end of the first transmission line 34 , and the electrical length of the end-open stub 35 being 90° with respect to the doubled wave
- 36 denotes a second transmission line with one end connected to the other end of the first transmission line 34
- 37 denotes an end-open stub for blocking the passage of the fundamental wave, one end of the end
- the input-side -matching circuit 31 serves for matching on the input side of the HBT 32 at the fundamental wave frequency f 0
- the output-side matching circuit 38 serves for matching on the output side of the HBT 32 at the quadrupled wave frequency 4 f 0
- the matching circuits 31 , 38 serve also as bias circuits, where the bias is set so that the HBT 32 operates at around the pinch-off.
- the frequency multiplier of this constitution is similar in constitution to the frequency multiplier of the first embodiment except the transmission line 33 inserted between the emitter of the HBT 32 and the ground GND. Accordingly, the frequency multiplier of this third embodiment has the same effects as the frequency multiplier of the first embodiment.
- the first embodiment has a problem that when the lengths of the transmission lines 3 , 5 shown in FIG. 1 are optimized so that a maximum multiplication gain is obtained, the reflection coefficient on the input side of the HBT 2 becomes so large that input-side matching is often difficult to obtain, and that the reflection coefficient becomes 1 or more, causing occurrence of oscillation.
- the transmission line 33 is set to an electrical length of about 10° with respect to the fundamental wave, i.e., an electrical length of 5-15°.
- FIG. 4 is a circuit diagram of a frequency multiplier according to a fourth embodiment of the present invention.
- Reference numeral 41 denotes an input-side matching circuit to which an input signal with frequency f0 is inputted
- 42 denotes an HBT in which an output terminal of the input-side matching circuit 41 is connected to the base
- 43 denotes an inductor for connecting the emitter of the HBT 42 and the ground GND to each other
- 44 denotes a first inductor with one end connected to the collector of the HBT 42
- 45 denotes an inductor with one end connected to the other end of the first inductor 44
- 46 denotes a capacitor connected between one end of the inductor 45 and the ground GND
- 47 denotes a capacitor connected between the other end of the inductor 45 and the ground GND
- 48 denotes a second inductor with one end connected to the other end of the first inductor 44
- 49 denotes an inductor with one end connected to the other end of the in
- the input-side matching circuit 41 serves for matching on the input side of the HBT 42 at the fundamental wave frequency f 0
- the output-side matching circuit 52 serves for matching on the output side of the HBT 42 at the quadrupled wave frequency 4 f 0
- the matching circuits 41 , 52 serve also as bias circuits, where the bias is set so that the HBT 42 operates at around the pinch-off.
- the frequency multiplier of this constitution is similar in constitution to the frequency multiplier of the second embodiment except the inductor 43 inserted between the emitter of the HBT 42 and the ground GND. Accordingly, the frequency multiplier of this fourth embodiment has the same effects as the frequency multiplier of the second embodiment.
- the inductor 43 inserted between the emitter of the HBT 42 and the ground GND, the reflection coefficient on the input side of the HBT 42 can be reduced, so that the input-side matching can be easily attained without significantly losing the multiplication gain. As a result of this, the reflection characteristics at the input end of this frequency multiplier can be improved and the circuit operation can be stabilized. It is noted that the inductor 43 is set to about a few ⁇ with respect to the fundamental wave, i.e., 1-10 ⁇ .
- an HBT has been employed as the high frequency transistor in the above first to fourth embodiments, it is also effective to constitute the frequency multiplier of the present invention by using a MESFET (MEtal Semiconductor Field Effect Transistor) or HEMT.
- MESFET MEtal Semiconductor Field Effect Transistor
- HEMT HEMT
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Abstract
One end of a first transmission line is connected to the collector of an HBT with the base connected to an output terminal of an input-side matching circuit and with the emitter grounded, and one end of an end-open stub for blocking the passage of the doubled wave is connected to the other end of the first transmission line. One end of a second transmission line is connected to the other end of the first transmission line, and one end of an end-open stub for blocking the passage of the fundamental wave is connected to the other end of the second transmission line. An input terminal of an output-side matching circuit is connected to the other end of the second transmission line. The fundamental wave is reflected toward the HBT at the connecting point of the end-open stub for blocking the passage of the fundamental wave, while the doubled wave is reflected toward the HBT at the connecting point of the end-open stub for blocking the passage of the doubled wave, by which only harmonics of quadrupled wave or higher-ordered waves are outputted via the output-side matching circuit. Thus, the frequency multiplier is capable of taking out fourth- or higher-ordered harmonics efficiently with a simple constitution using one high frequency transistor, and can be reduced in size and stabilized in operation.
Description
- The present invention relates to a frequency multiplier to be used as a high-stability, low-noise signal source for microwave and millimeter-wave communication systems.
- As a constitution of the high-stability, low-noise signal source for microwave and millimeter-wave communication systems, there has been provided a technique that with a plurality of frequency multipliers connected in series on the output side of a PLL (phase-locked loop) oscillator that generates low frequency signals, an output frequency of the PLL oscillator is sequentially multiplied to obtain a signal of a desired frequency. In such a PLL oscillator, conventionally, it has been common practice to connect in series frequency multipliers that doubles the frequency.
- An example of the frequency multiplier as a doubler is shown in “Monolithic Microwave Integrated Circuits (edited by the Institute of Electronics, Information and Communication Engineers), pp. 125-127”. This frequency multiplier, as shown in FIG. 7, comprises an input-
side matching circuit 101, an FET (Field Effect Transistor) 102, atransmission line 103, an end-open stub 104, and an output-side matching circuit 105. - In the frequency multiplier of this constitution, with the gate of the
FET 102 biased to around the pinch-off, a large-amplitude input signal with frequency f0 is inputted to the gate of theFET 102 via thematching circuit 101. Then, the drain waveform of theFET 102 becomes close to a half-wave rectified one, which has a large portion of frequency components that are integral multiples of the input signal frequency f0, particularly even-ordered frequency components. On the drain side of theFET 102, a fundamental-wave trap circuit employing the end-open stub 104 is used to suppress the fundamental wave. Because the length of the end-open stub 104 is selected so as to be an electrical length of 90° with respect to the fundamental wave of the input signal, the connecting point of the end-open stub 104 is short-circuited to the input signal fundamental wave and appears open to the doubled wave, so that fundamental-wave components are suppressed and the doubled wave is outputted. This frequency multiplier has an additional amplification effect by theFET 102 so that a high-efficiency frequency multiplication can be achieved. - Also, an example of frequency multipliers that quadruple the frequency at one stage with a view to reduction in the number of stages to be connected is shown in “A {fraction (15/60)} ONE-STAGE MMIC FREQUENCY QUADRUPLER”, IEEE, 1996 Microwave and Millimeter-Wave Monolithic Circuits Symposium pp. 35-38”.
- This frequency multiplier as a quadrupler, as shown in FIG. 8, comprises an input-
side matching circuit 201, atransmission line 202, an end-open stub 203 having an electrical length of 90° with respect to the doubled wave, an end-open stub 204 having an electrical length of 90° with respect to the quadrupled wave, an HEMT (High Electron Mobility Transistor) 205, atransmission line 206, an end-open stub 207 having an electrical length of 90° with respect to the doubled wave, an end-open stub 208 having an electrical length of 90° with respect to the fundamental wave, and an output-side matching circuit 209. Because the end-open stub 208 having an electrical length of 90° with respect to the fundamental wave and the end-open stub 207 having an electrical length of 90° with respect to the doubled wave are connected to the circuit on the drain side of theHEMT 205, there appears no signals of the fundamental wave (frequency f0) and the doubled wave (frequency 2f0). These end-open stubs are open to the signal of the quadrupled wave (frequency 4f0), so that the signal of the quadrupled wave is outputted. Also, because the end-open stub 203 having an electrical length of 90° with respect to the doubled wave and the end-open stub 204 having an electrical length of 90° with respect to the quadrupled wave are connected to the input side, signals of the doubled wave (frequency 2f0) and the quadrupled wave (frequency 4f0) reflected from the HEMT 205 toward the input side are suppressed. - With regard to the frequency multiplier as a doubler, when frequency multipliers are connected in series in multiple stages to obtain a desired frequency, the number of high-frequency transistors (FETs) increases with increasing number of order of frequency multiplication. This causes problems of increased complexity of the circuit and increased power consumption.
- Also, in frequency multipliers as doublers and frequency multipliers as quadruplers, at voltages higher than the pinch-off, the drain current of the FETs (including HEMTs) generally exhibits a square characteristic to the gate voltage. This causes a problem of poor efficiency at the time when harmonics of tripled wave or higher-ordered waves are taken out.
- Therefore, an object of the present invention is to provide a frequency multiplier which is capable of taking out fourth- or higher-ordered harmonics efficiently with a simple constitution using one high frequency transistor, and which can be reduced in size and stabilized in operation.
- In order to achieve the aforementioned object, there is provided a frequency multiplier comprising:
- an input-side matching circuit;
- a high frequency transistor with base or gate connected to an output terminal of the input-side matching circuit and with emitter or source grounded;
- first signal transmission means with one end connected to collector or drain of the high frequency transistor;
- doubled-wave reflection means with one end connected to the other end of the first signal transmission means;
- second signal transmission means with one end connected to the other end of the first signal transmission means;
- fundamental-wave reflection means with one end connected to the other end of the second signal transmission means; and
- an output-side matching circuit with its input terminal connected to the other end of the second signal transmission means.
- In an embodiment of the present invention, the first signal transmission means is a first transmission line;
- the second signal transmission means is a second transmission line;
- the doubled-wave reflection means is an end-open stub for blocking passage of a doubled wave; and
- the fundamental-wave reflection means is an end-open stub for blocking passage of a fundamental wave.
- According to this frequency multiplier, when an input signal is inputted to the base of the high frequency transistor (e.g., bipolar transistor) via the input-side matching circuit, the collector current of the high frequency transistor increases exponentially relative to the base voltage, so that many harmonics are outputted. Then, because a short-circuit to the fundamental wave is formed at the connecting point of the end-open stub for blocking the passage of the fundamental wave, the fundamental wave is reflected toward the high frequency transistor. Also, because a short-circuit to the doubled wave is formed at the connecting point of the end-open stub for blocking the passage of the doubled wave, the doubled wave is reflected toward the high frequency transistor. Thus, only harmonics of quadrupled wave or higher-ordered waves are outputted via the output-side matching circuit. When this occurs, the fundamental wave is reflected toward the high frequency transistor by the end-open stub for blocking the passage of the fundamental wave, so that the output power of the doubled wave is increased by the multiplying effect of the high frequency transistor. The doubled wave of increased output power is further reflected toward the high frequency transistor by the end-open stub for blocking the passage of the doubled wave, so that the output power of the quadrupled wave is further increased by the multiplying effect of the high frequency transistor. Also, in order that the fundamental wave is converted to the doubled wave to a maximum while the doubled wave is converted to the quadrupled wave to a maximum, the electrical lengths of the first transmission line and the second transmission line are optimized to, for example, about 10-40° with respect to the fundamental wave, by which the output efficiency of the quadrupled wave is increased. Further, by appropriately setting the characteristic impedances of the end-open stub for blocking the passage of the doubled wave and the end-open stub for blocking the passage of the fundamental wave to, for example, about 20-70Ω, the doubled wave can be effectively suppressed without narrowing the frequency band of the quadrupled wave. Thus, the frequency multiplier is capable of taking out fourth- or higher-ordered harmonics efficiently with a simple constitution using one high frequency transistor, particularly taking out the quadrupled wave with high output efficiency. In addition, similar effects can be obtained also by using as the high frequency transistor a MESFET (MEtal Semiconductor Field Effect Transistor) or HEMT (High Electron Mobility Transistor) or the like.
- In an embodiment of the present invention, the first signal transmission means is a first inductor;
- the second signal transmission means is a second inductor;
- the doubled-wave reflection means is a circuit generally equivalent to an end-open stub for blocking passage of a doubled wave, the circuit being an equivalent circuit for blocking passage of the doubled wave and being constituted by a concentrated constant circuit using an inductor and a capacitor; and
- the fundamental-wave reflection means is a circuit generally equivalent to an end-open stub for blocking passage of a fundamental wave, the circuit being an equivalent circuit for blocking passage of the fundamental wave and being constituted by a concentrated constant circuit using an inductor and a capacitor.
- According to this frequency multiplier, when an input signal is inputted to the base of the high frequency transistor (e.g., bipolar transistor) via the input-side matching circuit, the collector current of the high frequency transistor increases exponentially relative to the base voltage, so that many harmonics are outputted. Then, because a short-circuit to the fundamental wave is formed at the connecting point of the equivalent circuit for blocking the passage of the fundamental wave, the fundamental wave is reflected toward the high frequency transistor. Also, because a short-circuit to the doubled wave is formed at the connecting point of the equivalent circuit for blocking the passage of the doubled wave, the doubled wave is reflected toward the high frequency transistor. Thus, only harmonics of quadrupled wave or higher-ordered waves are outputted via the output-side matching circuit. When this occurs, the fundamental wave is reflected toward the high frequency transistor by the equivalent circuit for blocking the passage of the fundamental wave, so that the output power of the doubled wave is increased by the multiplying effect of the high frequency transistor. The doubled wave of increased output power is further reflected toward the high frequency transistor by the equivalent circuit for blocking the passage of the doubled wave, so that the output power of the quadrupled wave is further increased by the multiplying effect of the high frequency transistor. Also, in order that the fundamental wave is converted to the doubled wave to a maximum while the doubled wave is converted to the quadrupled wave to a maximum, the reactances of the first inductor and the second inductor are optimized, by which the output efficiency of the quadrupled wave is increased. Thus, the frequency multiplier is capable of taking out fourth- or higher-ordered harmonics efficiently with a simple constitution using one high frequency transistor, particularly taking out the quadrupled wave with high output efficiency. Furthermore, when the inductors are implemented by chip inductors or spiral inductors and the capacitors are implemented by chip capacitors or MIM capacitors, and when the distributed constant circuits of the end-open stubs are replaced with concentrated constant circuits using inductors and capacitors, the circuit occupancy area can be reduced. In this case, in particular, effects can be obtained when an MMIC is implemented by using spiral inductors and MIM capacitors. In addition, similar effects can be obtained also by using as the high frequency transistor a MESFET or HEMT or the like.
- In an embodiment of the present invention, the emitter or the source of the high frequency transistor is grounded via a transmission line.
- According to this frequency multiplier, by inserting a transmission line between the emitter (or source) of the high frequency transistor and the ground, the reflection coefficient on the input side of the high frequency transistor can be reduced, so that the input-side matching can be easily attained without significantly losing the multiplication gain. As a result of this, the reflection characteristics at the input end of this frequency multiplier can be improved and the circuit operation can be stabilized. It is noted that the electrical length of the transmission line is preferably 1-15° with respect to the fundamental wave.
- In an embodiment of the present invention, the emitter or the source of the high frequency transistor is grounded via an inductor.
- According to this frequency multiplier, by inserting an inductor between the emitter (or source) of the high frequency transistor and the ground, the reflection coefficient on the input side of the high frequency transistor can be reduced, so that the input-side matching can be easily attained without significantly losing the multiplication gain. As a result of this, the reflection characteristics at the input end of this frequency multiplier can be improved and the circuit operation can be stabilized. It is noted that the reactance of the inductor is preferably 1-10Ω with respect to the fundamental wave.
- In an embodiment of the present invention, the high frequency transistor is a heterojunction bipolar transistor.
- According to this frequency multiplier, in a comparison between the harmonic output characteristics of the HBT (Heterojunction Bipolar Transistor) and another high frequency transistor, for example, an HEMT, which are operated at around the pinch-off, the difference between fundamental wave and doubled wave is similar in level to each other, whereas the output power ratio of third- or higher-ordered harmonics is higher in the HBT than the HEMT. Thus, the output power of harmonics can be increased by employing the HBT as the high frequency transistor.
- The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
- FIG. 1 is a circuit diagram of a frequency multiplier according to a first embodiment of the present invention;
- FIG. 2 is a circuit diagram of a frequency multiplier according to a second embodiment of the present invention;
- FIG. 3 is a circuit diagram of a frequency multiplier according to a third embodiment of the present invention;
- FIG. 4 is a circuit diagram of a frequency multiplier according to a fourth embodiment of the present invention;
- FIG. 5 is a chart showing harmonic output characteristics at the pinch-off of the HBT;
- FIG. 6 is a chart showing harmonic output characteristics at the pinch-off of the HEMT;
- FIG. 7 is a circuit diagram showing a frequency multiplier serving as a doubler according to the prior art; and
- FIG. 8 is a circuit diagram showing a frequency multiplier serving as a quadrupler according to the prior art.
- Hereinbelow, the frequency multiplier of the present invention is described in detail by embodiments thereof illustrated in the accompanying drawings.
- FIG. 1 is a circuit diagram of a frequency multiplier according to a first embodiment of the present invention.
Reference numeral 1 denotes an input-side matching circuit to which an input signal with frequency f0 is inputted, 2 denotes an HBT (Heterojunction Bipolar Transistor) in which an output terminal of the input-side matching circuit 1 is connected to the base, and in which the emitter is connected to the ground GND, 3 denotes a first transmission line with one end connected to the collector of theHBT open stub 4 being connected to the other end of thefirst transmission line 3, and the electrical length of the end-open stub 4 being 90° with respect to the doubled wave, 5 denotes a second transmission line with one end connected to the other end of thefirst transmission line open stub 6 being connected to the other end of thesecond transmission line 5, and the electrical length of the end-open stub 6 being 90° with respect to the fundamental wave, and 7 denotes an output-side matching circuit with its input terminal connected to the other end of thesecond transmission line 5. The input-side matching circuit 1 serves for matching on the input side of theHBT 2 at the fundamental wave frequency f0, and the output-side matching circuit 7 serves for matching on the output side of theHBT 2 at the quadrupled wave frequency 4f0. The matchingcircuits HBT 2 operates at around the pinch-off. - In the frequency multiplier of this constitution, an input signal with frequency f0 is inputted to the base of the
HBT 2 via the input-side matching circuit 1. Because the collector current of theHBT 2 increases exponentially relative to the base voltage, many harmonics are outputted. Then, the connecting point of the end-open stub 6 for blocking the passage of the fundamental wave with the electrical length of 90° to the fundamental wave (frequency f0) is short-circuited to the fundamental wave (frequency f0), so that the fundamental wave is reflected toward theHBT 2. Also, the connecting point of the end-open stub 4 for blocking the passage of the doubled wave with the electrical length of 90° to the doubled wave (frequency 2f0) is short-circuited to the doubled wave, so that the doubled wave is reflected toward theHBT 2. Thus, only fourth- or higher-ordered harmonics are outputted via thematching circuit 7. - When the characteristic impedance Zc1 of the end-
open stub 6 for blocking the passage of the fundamental wave and the characteristic impedance Zc2 of the end-open stub 4 for blocking the passage of the doubled wave are small, the frequency band becomes wider but the suppression ratio of the fundamental wave (frequency f0) and the doubled wave (frequency 2f0) becomes smaller. On the other hand, when the characteristic impedances Zc1 and Zc2 are large, the suppression ratio of the fundamental wave (frequency f0) and the doubled wave (frequency 2f0) becomes larger but the frequency band becomes narrower. That is, the suppression of the doubled wave (frequency 2f0) and the frequency band are in a trade-off relation, and normally the characteristic impedances Zc1 and zc2 are selected within a range of 20-70Ω. - Also, because the fundamental wave is reflected toward the
HBT 2 by the end-open stub 6 for blocking the passage of the fundamental wave with the electrical length of 90° to the fundamental wave (frequency f0), the output power of the doubled wave (frequency 2f0) is increased by the multiplying effect of theHBT 2. The doubled wave of increased output power is reflected toward theHBT 2 by the end-open stub 4 for blocking the passage of the doubled wave with the electrical length of 90° to the doubled wave, so that the output power of the quadrupled wave is further increased by the multiplying effect of theHBT 2. Furthermore, there exist an optimum length total (Ld1+Ld2) of thetransmission line 3 and thetransmission line 5 for converting the fundamental wave to the doubled wave to a maximum, as well as an optimum length Ld1 of thetransmission line 3 for converting the doubled wave to the quadrupled wave to a maximum. By independently optimizing the points at which the fundamental wave and the doubled wave are reflected with those twotransmission lines - In addition, although the optimum lengths of the two
transmission lines open stub 4 for blocking the passage of the doubled wave, the end-open stub 6 for blocking the passage of the fundamental wave and thetransmission lines - Like this, this frequency multiplier is capable of taking out fourth- or higher-ordered harmonics with a simple constitution using one HBT and, in particular, taking out the quadrupled wave with high output efficiency.
- Whereas the drain current of an FET used for conventional frequency multipliers exhibits a square characteristic to the gate voltage, the collector current of the HBT used in this first embodiment increases exponentially relative to the base voltage. Accordingly, when the HBT is operated at around the pinch-off, the output power of third- or higher-ordered harmonics becomes larger as compared with the FET.
- Also, FIG. 5 shows harmonic output characteristics at the pinch-off of the HBT, and FIG. 6 shows harmonic output characteristics at the pinch-off of the HEMT. Both HBT and HEMT are devices having a maximum frequency fmax of 60-70 GHz and a rated current of about 40 mA. As shown in FIGS. 5 and 6, in a comparison of output harmonics between the HBT and the HEMT, which are operated at around the pinch-off, it can be seen that while the difference between fundamental wave and doubled wave is about 10 dB in either case of HBT and HEMT, the difference between fundamental wave and tripled wave is 33 dB in HEMT and 18 dB in HBT and the difference between fundamental wave and quadrupled wave is 32 dB in HEMT and 22 dB in HBT, so that the output power ratio of third- or higher-ordered harmonics is 10 dB or more higher in the HBT than in the HEMT. Accordingly, employing the HBT as the high frequency transistor makes it possible to increase the output power of harmonics.
- FIG. 2 is a circuit diagram of a frequency multiplier according to a second embodiment of the present invention.
Reference numeral 11 denotes an input-side matching circuit to which an input signal with frequency f0 is inputted, 12 denotes an HBT in which an output terminal of the input-side matching circuit 11 is connected to the base, and in which the emitter is connected to the ground GND, 13 denotes a first inductor with one end connected to the collector of theHBT first inductor 13, 15 denotes a capacitor connected between one end of theinductor 14 and the ground GND, 16 denotes a capacitor connected between the other end of theinductor 14 and the ground GND, 17 denotes a second inductor with one end connected to the other end of thefirst inductor inductor inductor 18 and the ground GND, 20 denotes a capacitor connected between the other end of theinductor 18 and the ground GND, and 21 denotes an output-side matching circuit with its input terminal connected to the other end of thesecond inductor 17. The input-side matching circuit 11 serves for matching on the input side of theHBT 12 at the fundamental wave frequency f0, and the output-side matching circuit 21 serves for matching on the output side of theHBT 12 at the quadrupled wave frequency 4f0. The matchingcircuits HBT 12 operates at around the pinch-off. - In this frequency multiplier, instead of the end-
open stub 6 for blocking the passage of the fundamental wave shown in FIG. 1 in the first embodiment, an equivalent circuit for blocking the passage of the fundamental wave, in which the end-open stub 6 for blocking the passage of the fundamental wave has been converted into a concentrated constant circuit being constituted by theinductor 18, thecapacitor 19 and thecapacitor 20. Also, instead of the end-open stub 4 for blocking the passage of the doubled wave shown in FIG. 1 in the first embodiment, an equivalent circuit for blocking the passage of the doubled wave, in which the end-open stub 4 for blocking the passage of the doubled wave has been converted into a concentrated constant circuit being constituted by theinductor 14, the capacitor 15 and thecapacitor 16. - Assuming that, in FIG. 1, the characteristic impedance of the end-
open stub 6 for blocking the passage of the fundamental wave is Zc1 and the characteristic impedance of the end-open stub 4 for blocking the passage of the doubled wave is Zc2, and that, in FIG. 2, the inductances of theinductors capacitors capacitors 15, 16 is C2, then setting that - L1=Zc1/(2πf0)
- C1=1/(2πf0·Zc1)
- makes it possible to replace the end-
open stub 6 for blocking the passage of the fundamental wave in FIG. 1 by an equivalent circuit for blocking the passage of the fundamental wave employing inductors and capacitors. Besides, setting that - L2=Zc2/(4πf0)
- C2=1/(4πf0·Zc2)
- makes it possible to replace the end-
open stub 4 for blocking the passage of the doubled wave in FIG. 1 by an equivalent circuit for blocking the passage of the doubled wave employing inductors and capacitors. - Further, in this frequency multiplier, the
first inductor 13 is used instead of thefirst transmission line 3 of FIG. 1, and thesecond inductor 17 is used instead of thesecond transmission line 5 of FIG. 1. Although the optimum reactance of the first,second inductors first inductor 13 is 10-40Ω with respect to the fundamental wave and the reactance of thesecond inductor 17 is 10-40Ω with respect to the fundamental wave. - Accordingly, the frequency multiplier of this second embodiment has the same effects as the frequency multiplier of the first embodiment.
- Referring to FIG. 2, when the
inductors capacitors open stub 6 for blocking the passage of the fundamental wave and the end-open stub 4 for blocking the passage of the doubled wave with the concentrated constant circuits is effective for circuits of up to about 10 GHz. - FIG. 3 is a circuit diagram of a frequency multiplier according to a third embodiment of the present invention.
Reference numeral 31 denotes an input-side matching circuit to which an input signal with frequency f0 is inputted, 32 denotes an HBT in which an output terminal of the input-side matching circuit 31 is connected to the base, 33 denotes a transmission line for connecting the emitter of theHBT 32 and the ground GND to each other, 34 denotes a first transmission line with one end connected to the collector of theHBT 32, 35 denotes an end-open stub for blocking the passage of the doubled wave, one end of the end-open stub 35 being connected to the other end of thefirst transmission line 34, and the electrical length of the end-open stub 35 being 90° with respect to the doubled wave, 36 denotes a second transmission line with one end connected to the other end of thefirst transmission line open stub 37 being connected to the other end of thesecond transmission line 36, and the electrical length of the end-open stub 37 being 90° with respect to the fundamental wave, and 38 denotes an output-side matching circuit with its input terminal connected to the other end of thesecond transmission line 36. The input-side -matchingcircuit 31 serves for matching on the input side of theHBT 32 at the fundamental wave frequency f0, and the output-side matching circuit 38 serves for matching on the output side of theHBT 32 at the quadrupled wave frequency 4f0. The matchingcircuits HBT 32 operates at around the pinch-off. - The frequency multiplier of this constitution is similar in constitution to the frequency multiplier of the first embodiment except the
transmission line 33 inserted between the emitter of theHBT 32 and the ground GND. Accordingly, the frequency multiplier of this third embodiment has the same effects as the frequency multiplier of the first embodiment. - The first embodiment has a problem that when the lengths of the
transmission lines HBT 2 becomes so large that input-side matching is often difficult to obtain, and that the reflection coefficient becomes 1 or more, causing occurrence of oscillation. Thus, in this third embodiment, by inserting thetransmission line 33 between the emitter of theHBT 32 and the ground GND, the reflection coefficient on the input side of theHBT 32 can be reduced so that the input-side matching can be easily attained without significantly losing the multiplication gain. As a result of this, the reflection characteristics at the input end of this frequency multiplier can be improved and the circuit operation can be stabilized. It is noted that thetransmission line 33 is set to an electrical length of about 10° with respect to the fundamental wave, i.e., an electrical length of 5-15°. - FIG. 4 is a circuit diagram of a frequency multiplier according to a fourth embodiment of the present invention.
Reference numeral 41 denotes an input-side matching circuit to which an input signal with frequency f0 is inputted, 42 denotes an HBT in which an output terminal of the input-side matching circuit 41 is connected to the base, 43 denotes an inductor for connecting the emitter of theHBT 42 and the ground GND to each other, 44 denotes a first inductor with one end connected to the collector of theHBT first inductor inductor 45 and the ground GND, 47 denotes a capacitor connected between the other end of theinductor 45 and the ground GND, 48 denotes a second inductor with one end connected to the other end of thefirst inductor inductor inductor 49 and the ground GND, 51 denotes a capacitor connected between the other end of theinductor 49 and the ground GND, and 52 denotes an output-side matching circuit with its input terminal connected to the other end of theinductor 48. The input-side matching circuit 41 serves for matching on the input side of theHBT 42 at the fundamental wave frequency f0, and the output-side matching circuit 52 serves for matching on the output side of theHBT 42 at the quadrupled wave frequency 4f0. The matchingcircuits HBT 42 operates at around the pinch-off. - In this frequency multiplier, instead of the end-
open stub 6 for blocking the passage of the fundamental wave shown in FIG. 1 in the first embodiment, an equivalent circuit for blocking the passage of the fundamental wave, in which the end-open stub 6 for blocking the passage of the fundamental wave has been converted into a concentrated constant circuit being constituted by theinductor 49, thecapacitor 50 and thecapacitor 51. Also, instead of the end-open stub 4 for blocking the passage of the doubled wave shown in FIG. 1 in the first embodiment, an equivalent circuit for blocking the passage of the doubled wave, in which the end-open stub 4 for blocking the passage of the doubled wave has been converted into a concentrated constant circuit being constituted by theinductor 45, thecapacitor 46 and thecapacitor 47. - The frequency multiplier of this constitution is similar in constitution to the frequency multiplier of the second embodiment except the
inductor 43 inserted between the emitter of theHBT 42 and the ground GND. Accordingly, the frequency multiplier of this fourth embodiment has the same effects as the frequency multiplier of the second embodiment. - Also, by the
inductor 43 inserted between the emitter of theHBT 42 and the ground GND, the reflection coefficient on the input side of theHBT 42 can be reduced, so that the input-side matching can be easily attained without significantly losing the multiplication gain. As a result of this, the reflection characteristics at the input end of this frequency multiplier can be improved and the circuit operation can be stabilized. It is noted that theinductor 43 is set to about a few Ω with respect to the fundamental wave, i.e., 1-10Ω. - Although an HBT has been employed as the high frequency transistor in the above first to fourth embodiments, it is also effective to constitute the frequency multiplier of the present invention by using a MESFET (MEtal Semiconductor Field Effect Transistor) or HEMT.
- The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Claims (10)
1. A frequency multiplier comprising:
an input-side matching circuit;
a high frequency transistor with base or gate connected to an output terminal of the input-side matching circuit and with emitter or source grounded;
first signal transmission means with one end connected to collector or drain of the high frequency transistor;
doubled-wave reflection means with one end connected to the other end of the first signal transmission means;
second signal transmission means with one end connected to the other end of the first signal transmission means;
fundamental-wave reflection means with one end connected to the other end of the second signal transmission means; and
an output-side matching circuit with its input terminal connected to the other end of the second signal transmission means.
2. The frequency multiplier according to , wherein:
claim 1
the first signal transmission means is a first transmission line;
the second signal transmission means is a second transmission line;
the doubled-wave reflection means is an end-open stub for blocking passage of a doubled wave; and
the fundamental-wave reflection means is an end-open stub for blocking passage of a fundamental wave.
3. The frequency multiplier according to , wherein:
claim 2
both the end-open stub for blocking passage of the doubled wave and the end-open stub for blocking passage of the fundamental wave have a characteristic impedance of 20-70Ω; and
both the first transmission line and the second transmission line have an electrical length of 10-40° with respect to the fundamental wave.
4. The frequency multiplier according to , wherein:
claim 1
the first signal transmission means is a first inductor;
the second signal transmission means is a second inductor;
the doubled-wave reflection means is a circuit generally equivalent to an end-open stub for blocking passage of a doubled wave, the circuit being an equivalent circuit for blocking passage of the doubled wave and being constituted by a concentrated constant circuit using an inductor and a capacitor; and
the fundamental-wave reflection means is a circuit generally equivalent to an end-open stub for blocking passage of a fundamental wave, the circuit being an equivalent circuit for blocking passage of the fundamental wave and being constituted by a concentrated constant circuit using an inductor and a capacitor.
5. The frequency multiplier according to , wherein:
claim 4
the first inductor has a reactance of 10-40Ω with respect to the fundamental wave; and
the second inductor has a reactance of 2-10Ω with respect to the fundamental wave.
6. The frequency multiplier according to , wherein
claim 1
the emitter or the source of the high frequency transistor is grounded via a transmission line.
7. The frequency multiplier according to , wherein
claim 6
the transmission line has an electrical length of 5-15° with respect to the fundamental wave.
8. The frequency multiplier according to , wherein
claim 1
the emitter or the source of the high frequency transistor is grounded via an inductor.
9. The frequency multiplier according to , wherein
claim 8
the inductor has a reactance of 1-10Ω with respect to the fundamental wave.
10. The frequency multiplier according to , wherein
claim 1
the high frequency transistor is a heterojunction bipolar transistor.
Priority Applications (1)
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US09/758,366 US6369675B2 (en) | 1998-11-18 | 2001-01-12 | Frequency multiplier capable of taking out efficiently and stably harmonics higher than fourth order |
Applications Claiming Priority (4)
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JP10-328197 | 1998-11-18 | ||
JP10328197A JP2000156611A (en) | 1998-11-18 | 1998-11-18 | Frequency multiplier |
US09/440,762 US6198365B1 (en) | 1998-11-18 | 1999-11-16 | Frequency multiplier capable of taking out efficiently and stably harmonics higher than fourth order |
US09/758,366 US6369675B2 (en) | 1998-11-18 | 2001-01-12 | Frequency multiplier capable of taking out efficiently and stably harmonics higher than fourth order |
Related Parent Applications (1)
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US09/440,762 Continuation US6198365B1 (en) | 1998-11-18 | 1999-11-16 | Frequency multiplier capable of taking out efficiently and stably harmonics higher than fourth order |
Publications (2)
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US20010010473A1 true US20010010473A1 (en) | 2001-08-02 |
US6369675B2 US6369675B2 (en) | 2002-04-09 |
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US09/440,762 Expired - Lifetime US6198365B1 (en) | 1998-11-18 | 1999-11-16 | Frequency multiplier capable of taking out efficiently and stably harmonics higher than fourth order |
US09/758,366 Expired - Fee Related US6369675B2 (en) | 1998-11-18 | 2001-01-12 | Frequency multiplier capable of taking out efficiently and stably harmonics higher than fourth order |
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US09/440,762 Expired - Lifetime US6198365B1 (en) | 1998-11-18 | 1999-11-16 | Frequency multiplier capable of taking out efficiently and stably harmonics higher than fourth order |
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US (2) | US6198365B1 (en) |
EP (1) | EP1003277B1 (en) |
JP (1) | JP2000156611A (en) |
DE (1) | DE69905686T2 (en) |
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JP2000223951A (en) * | 1999-01-27 | 2000-08-11 | Murata Mfg Co Ltd | Frequency multiplier and radio equipment using the same |
US6242009B1 (en) | 1999-04-20 | 2001-06-05 | Kareem I. Batarseh | Microbicidal formulations and methods to control microorganisms |
JP3366314B2 (en) * | 2000-02-29 | 2003-01-14 | 富士通カンタムデバイス株式会社 | Microwave frequency multiplier |
US6967540B2 (en) * | 2003-03-06 | 2005-11-22 | Paratek Microwave, Inc. | Synthesizers incorporating parascan TM varactors |
CN100438335C (en) * | 2004-05-28 | 2008-11-26 | 威盛电子股份有限公司 | Circuit for automatic coordinating resistance and capacitor time constant of semiconductor element and method thereof |
JP4425886B2 (en) | 2006-07-27 | 2010-03-03 | 住友電工デバイス・イノベーション株式会社 | Electronic circuit equipment |
US8018290B2 (en) * | 2006-10-17 | 2011-09-13 | Mitsubishi Electric Corporation | Oscillator, transmitter-receiver and frequency synthesizer |
JP5127362B2 (en) * | 2007-08-23 | 2013-01-23 | 三菱電機株式会社 | 2nd harmonic oscillator |
RU2522302C1 (en) * | 2013-05-07 | 2014-07-10 | Федеральное государственное унитарное предприятие "Научно-произвдственное предприятие "Исток" (ФГУП "НПП "Исток") | Frequency multiplier |
WO2016033559A1 (en) * | 2014-08-29 | 2016-03-03 | University Of Virginia | Balanced unilateral frequency quadrupler |
WO2018141398A1 (en) * | 2017-02-03 | 2018-08-09 | Telefonaktiebolaget Lm Ericsson (Publ) | A broadband frequency tripler |
CN109635607B (en) * | 2018-11-12 | 2019-11-08 | 晓函安全(北京)科技有限公司 | A kind of millimeter wave fairing realized towards single-chip |
KR102391222B1 (en) * | 2020-06-04 | 2022-04-27 | 동국대학교 산학협력단 | Injection locked frequency divider, phase locked loop and communication device with the same |
CN113054918B (en) * | 2021-03-10 | 2022-11-22 | 深圳大学 | Power amplifier circuit and microwave transmission equipment |
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JPS63217803A (en) * | 1987-03-06 | 1988-09-09 | Matsushita Electric Ind Co Ltd | Oscillation multiplier |
US4931921A (en) * | 1989-05-30 | 1990-06-05 | Motorola, Inc. | Wide bandwidth frequency doubler |
US5886595A (en) * | 1996-05-01 | 1999-03-23 | Raytheon Company | Odd order MESFET frequency multiplier |
EP1811647A1 (en) * | 1996-09-13 | 2007-07-25 | Denso Corporation | Voltage controlled oscillator |
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1998
- 1998-11-18 JP JP10328197A patent/JP2000156611A/en active Pending
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1999
- 1999-11-09 EP EP99122340A patent/EP1003277B1/en not_active Expired - Lifetime
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- 1999-11-16 US US09/440,762 patent/US6198365B1/en not_active Expired - Lifetime
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US6369675B2 (en) | 2002-04-09 |
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JP2000156611A (en) | 2000-06-06 |
DE69905686D1 (en) | 2003-04-10 |
US6198365B1 (en) | 2001-03-06 |
EP1003277B1 (en) | 2003-03-05 |
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