Disclosure of Invention
In order to solve the above problems, an object of the present invention is to provide a hybrid branch line coupler that simultaneously implements frequency and power division multiplexing, can meet the requirement for output power variation of an output signal, and can operate in a plurality of communication bands.
In order to make up for the defects of the prior art, the invention adopts the technical scheme that:
a hybrid branch line coupler for simultaneously realizing frequency and power division ratio structure comprises a hybrid coupler, wherein the hybrid coupler comprises a planar microstrip unit, a substrate and a stratum which are sequentially arranged from top to bottom;
the planar microstrip unit comprises a plurality of loading branch line couplers, the loading branch line couplers comprise branch line couplers, and the branch line couplers comprise microstrip lines A1, microstrip lines A2, microstrip lines A3, microstrip lines A4, impedance match lines B1, impedance match lines B2, impedance match lines B3, impedance match lines B4 and a pair of coupling lines D1; the microstrip line A1 and the microstrip line A2 are parallel to a horizontal axis, the microstrip line A3 and the microstrip line A4 are parallel to a vertical axis, the impedance match line B1 and the impedance match line B2 are respectively connected to two ends of the microstrip line A1 through external capacitors, and the impedance match line B3 and the impedance match line B4 are respectively connected to two ends of the microstrip line A2 through external capacitors;
the loaded branch line coupler further comprises a plurality of power division modules, each power division module comprises a blocking capacitor C4, a variable capacitance diode P1 and a radio frequency choke RFC1, one end of each blocking capacitor C4 is connected to one end of each variable capacitance diode P1 and one end of each radio frequency choke RFC1 respectively, the other end of each radio frequency choke RFC1 is connected with direct current voltage through an external lead, the other end of each variable capacitance diode P1 is grounded through a metal through hole, the two ends of each microstrip line A1 and A2 and the middle of each microstrip line A3 and A4 are respectively connected with an active division module and the other end of each blocking capacitor C4 in each power division module;
the loaded branch line coupler also comprises a varactor diode P2 and a radio frequency choke RFC 2; two ends of the coupling line D1 are respectively connected to one ends of a variable capacitance diode P2 and a radio frequency choke RFC2, the other end of the radio frequency choke RFC2 is connected with a direct current voltage through an external lead, and the other end of the variable capacitance diode P2 is grounded through a metal through hole.
Preferably, the varactor diode P1 and the varactor diode P2 both use MA46H201 chips.
Preferably, the substrate is made of Rogers RT/Duroid4003c material with the dielectric constant of 3.38 and the thickness of 0.813 mm.
Preferably, the formation is a metal formation.
Furthermore, the adjustable power ratio of the hybrid coupler is 3-10dB, and the adjustable frequency is 1.7GHz-2.9 GHz.
The invention has the beneficial effects that: the reconfigurable frequency and power division ratio is realized based on the branch line structure, so that the function of the power divider is realized, the adjustable working frequency can be realized, and the reconfigurable power divider is very suitable for the application of a modern wireless communication system; compared with the prior art, the variable capacitance diode is loaded on the branch line coupler, so that any power division ratio and any center frequency output can be realized, the whole structure is simple, the miniaturization can be realized, and the integration is easy; in addition, because of using the plane microstrip structure, so make simple and easy, the cost is lower; because the output frequency is adjustable, communication in a wide bandwidth range can be realized. Therefore, the invention has reasonable design and simple structure, can meet the requirement on the output power change of the output signal, can work in a plurality of communication frequency bands and is beneficial to improving the overall performance of a communication system.
Drawings
The following description of the preferred embodiments of the present invention will be made in conjunction with the accompanying drawings.
FIG. 1 is a side view block diagram of the present invention;
FIG. 2 is a schematic diagram of the loaded branch line coupler of the present invention;
FIG. 3 is a comparison graph of simulated and actual measured amplitude response results for the present invention at a center frequency of 2.9 GHz;
FIG. 4 is a graph comparing simulated and actual measured phase response results for the present invention at a center frequency of 2.9 GHz;
FIG. 5 is a comparison graph of simulated and actual measured amplitude response results for the present invention at a center frequency of 2.4 GHz;
FIG. 6 is a comparison graph of simulated and actual measured phase response results for the present invention at a center frequency of 2.4 GHz;
FIG. 7 is a comparison graph of simulated and actual measured amplitude response results for the present invention at a center frequency of 1.7 GHz;
FIG. 8 is a graph comparing simulated and actual measured phase response results for the present invention at a center frequency of 1.7 GHz;
FIG. 9 is a comparison graph of simulated and actual measured amplitude response results when the center frequency is 1.9GHz and the power division ratio is 6dB according to the present invention;
FIG. 10 is a comparison graph of simulated and actual measured phase response results for a center frequency of 1.9GHz and a power division ratio of 6dB in accordance with the present invention;
FIG. 11 is a comparison graph of simulated and actual measured amplitude response results when the center frequency is 1.9GHz and the power division ratio is 10dB according to the present invention;
FIG. 12 is a comparison graph of simulated and actual measured phase response results for a center frequency of 1.9GHz and a power split ratio of 10dB in accordance with the present invention;
FIG. 13 is a comparison graph of simulated and actual measured amplitude response results for the present invention at a center frequency of 2.0GHz and a power division ratio of 6 dB;
FIG. 14 is a comparison graph of simulated and actual measured phase response results for the present invention at a center frequency of 2.0GHz and a power split ratio of 6 dB;
FIG. 15 is a graph comparing simulated and actual measured amplitude response results for the present invention at a center frequency of 2.0GHz and a power split of 8 dB;
FIG. 16 is a graph comparing simulated and actual measured phase responses for the present invention at a center frequency of 2.0GHz and a power ratio of 8 dB;
FIG. 17 is a comparison graph of simulated and actual measured amplitude response results for the present invention at a center frequency of 2.0GHz and a power division ratio of 10 dB;
FIG. 18 is a comparison graph of simulated and actual measured phase response results for the present invention at a center frequency of 2.0GHz and a power split ratio of 10 dB;
FIG. 19 is a comparison graph of simulated and actual measured amplitude response results for the present invention at a center frequency of 2.1GHz and a power split ratio of 6 dB;
FIG. 20 is a comparison graph of simulated and actual measured phase response results for the present invention at a center frequency of 2.1GHz and a power split ratio of 6 dB;
FIG. 21 is a graph comparing simulated and actual measured amplitude response results for the present invention at a center frequency of 2.1GHz and a power split of 8 dB;
FIG. 22 is a graph comparing simulated and actual measured phase responses for the present invention at a center frequency of 2.1GHz and a power ratio of 8 dB.
Detailed Description
Referring to fig. 1 and 2, a hybrid branch line coupler for simultaneously implementing a frequency and power division ratio structure includes a hybrid coupler 1, where the hybrid coupler 1 includes a planar microstrip unit 101, a substrate 102, and a ground layer 103, which are sequentially arranged from top to bottom;
the planar microstrip unit 101 comprises a plurality of loaded branch line couplers, wherein each loaded branch line coupler comprises a branch line coupler, and each branch line coupler comprises a microstrip line A1, a microstrip line A2, a microstrip line A3, a microstrip line A4, an impedance match line B1, an impedance match line B2, an impedance match line B3, an impedance match line B4 and a pair of coupling lines D1; the microstrip line A1 and the microstrip line A2 are parallel to a horizontal axis, the microstrip line A3 and the microstrip line A4 are parallel to a vertical axis, the impedance match line B1 and the impedance match line B2 are respectively connected to two ends of the microstrip line A1 through external capacitors, and the impedance match line B3 and the impedance match line B4 are respectively connected to two ends of the microstrip line A2 through external capacitors;
the loaded branch line coupler further comprises a plurality of power division modules Q, each power division module Q comprises a blocking capacitor C4, a variable capacitance diode P1 and a radio frequency choke RFC1, one end of each blocking capacitor C4 is connected to one end of each variable capacitance diode P1 and one end of each radio frequency choke RFC1 respectively, direct current voltage is introduced to the other end of each radio frequency choke RFC1 through an external lead, the other end of each variable capacitance diode P1 is grounded through a metal through hole, the direct current voltage is supplied to the variable capacitance diodes P1, two ends of the microstrip line A1 and the microstrip line A2 and the middle parts of the microstrip line A3 and the microstrip line A4 are connected with the active division module Q respectively and are connected to the other end of the blocking capacitor C4 in the power division module Q;
the loaded branch line coupler also comprises a varactor diode P2 and a radio frequency choke RFC 2; two ends of the coupling line D1 are respectively connected to one ends of a variable capacitance diode P2 and a radio frequency choke RFC2, the other end of the radio frequency choke RFC2 is connected with a direct current voltage through an external lead, so that the direct current voltage is supplied to the variable capacitance diode P2, and the other end of the variable capacitance diode P2 is grounded through a metal via hole.
Specifically, the frequency and power division ratio reconfiguration is realized based on a branch line structure, so that the function of a power divider is realized, the adjustable working frequency can be realized, and the method is very suitable for the application of a modern wireless communication system; compared with the prior art, the variable capacitance diode is loaded on the branch line coupler, so that any power division ratio and any center frequency output can be realized, the whole structure is simple, the miniaturization can be realized, and the integration is easy; in addition, because of using the plane microstrip structure, so make simple and easy, the cost is lower; because the output frequency is adjustable, communication in a wide bandwidth range can be realized. Therefore, the invention has reasonable design and simple structure, can meet the requirement on the output power change of the output signal, can work in a plurality of communication frequency bands and is beneficial to improving the overall performance of a communication system.
By analogy, the coupler structure of the present invention can also be used for other passive devices, such as power splitters and the like.
The construction method of the invention can be as follows: further, in the present embodiment, the initial value of varactor P1 in the power division module Q connected to microstrip line a1 and microstrip line a2 is C1, the initial value of varactor P1 in the power division module Q connected to microstrip line A3 and microstrip line A4 is C2, and then the center frequency is fixed, and the capacitance value thereof is changed by changing the voltages on varactor P1 and varactor P2, where the initial value on varactor P2 is C3, thereby realizing different power division ratio outputs.
Preferably, the width and length of microstrip line a1 and microstrip line a2 are 4.1mm and 11.2mm, respectively, the width and length of microstrip line A3 and microstrip line a4 are 0.1mm and 10.5mm, respectively, the distance between the two coupled lines is 0.2mm, the radius of the metal via hole is 0.3mm, and the width and length of impedance match line B1, impedance match line B2, impedance match line B3 and impedance match line B4 are 1.8mm and 4.5mm, respectively. The direct-current voltage introduced by the radio-frequency choke RFC1 in the power division module Q connected to the microstrip line A1 and the microstrip line A2 is V1The direct current voltage introduced by the RFC1 in the power division module Q connected to the microstrip line A3 and the microstrip line A4 is V2The DC voltage passed by the RF choke RFC2 connected to the coupled line D1 is V3。
Preferably, the varactor diode P1 and the varactor diode P2 both adopt MA46H201 chips, and can provide a capacitance of 0.3-2.1pF in a bias voltage range of 0-20V.
Preferably, the substrate is made of Rogers RT/Duroid4003c material with the dielectric constant of 3.38 and the thickness of 0.813 mm.
Preferably, the formation 103 is a metal formation, which has good electrical conductivity.
Furthermore, the adjustable power ratio of the hybrid coupler 1 is 3-10dB, and the adjustable frequency is 1.7GHz-2.9 GHz.
Specifically, refer to table one and table two.
Watch 1
Watch two
According to the data in the table one and the table two, the different bias voltage values V corresponding to the adjustable center frequency of the embodiment of the invention1、V2、V3And a capacitance value C1、C2、C3It can be seen that when the loaded capacitance value is increased, the operating frequency of the hybrid coupler 1 is reduced, and it can be seen that, on the premise of ensuring that the conditions of equal power division, low reflection, high isolation and the like are satisfied, the operating frequency of the hybrid coupler 1 can be adjusted by changing the size of the loaded capacitance value.
In fig. 3 to 22, in particular, frequency refers to a center frequency,spark refers to S parameter, phase difference refers to phase, Measured refers to actual measurement, Simulated refers to simulation, and S (1,1) to S (4,1) refer to specific S parameter, i.e. S11、S21、S31And S41;
Referring to FIGS. 3 and 4, corresponding V at this time1=20V,V2=20V,V3The phase output of the central frequency (2.9GHz) of the coupler is 90 DEG at 20V, and the measured S parameter is S11=-17.5dB,S31=-4.05dB,S41=-5.01dB,S21=-15.2dB。
Referring to FIGS. 5 and 6, at this time V1=7.4V,V2=8.2V,V3=20V。
Referring to fig. 7 and 8, corresponding V1=1.2V,V2=3.6V,V3At 12V, the differential phase output at the center frequency (1.7GHz) of the coupler is 92.3 ° and the measured S parameter is S11=-13.3dB,S31=-4.42dB,S41=-4.97dB,S21=-20.1dB。
Referring to fig. 9 and 10, corresponding V1=10.0V、V2=5.3V、V3At 1.8V, the coupler now has better phase characteristics at 1.9 GHz.
Referring to fig. 11 and 12, corresponding V1=10.0V、V2=4.6V、V3At 1.5V, the coupler now has better phase characteristics at 1.9 GHz.
Referring to fig. 13 and 14, corresponding V1=16.0V、V2=6.0V、V3At 3.7V, the coupler now has better phase characteristics at 2.0 GHz.
Referring to fig. 15 and 16, corresponding V1=16.0V、V2=5.6V、V3The coupler has better phase characteristics at 2.0GHz at 2.6V.
Referring to fig. 17 and 18, corresponding V1=17.8V、V2=5.1V、V3At 2.1V, the coupler now has better phase characteristics at 2.0 GHz.
Referring to fig. 19 and 20, corresponding V1=20V、V2=9.2V、V34.1V, thisThe time coupler has better phase characteristics at 0.8 GHz.
Referring to fig. 21 and 22, corresponding V1=20V、V2=7.5V、V3At 2.7V, the coupler now has better phase characteristics at 2.1 GHz.
All the above results are measured by a network analyzer under a real environment that the substrate 102 is made of Rogers RT/Duroid4003c, has a dielectric constant of 3.38 and a thickness of 0.813 mm; the simulation and test comparison graph shows that the coincidence degree of the simulation and actual measurement curves is higher, and the scheme of the invention is practical and feasible.
While the preferred embodiments and basic principles of the present invention have been described in detail, it will be understood by those skilled in the art that the invention is not limited to the embodiments, but is intended to cover various modifications, equivalents and alternatives falling within the scope of the invention as claimed.