Utility model content
Purpose of utility model: the purpose of the utility model is to provide a kind of non-linear feedback circuit and using its low noise
Amplifier is able to solve the problem of temperature-compensation circuit is not suitable for low-noise amplifier in the prior art.
Technical solution: to reach this purpose, the utility model uses following technical scheme:
Non-linear feedback circuit described in the utility model, including at least one diode;When diode only one when,
The cathode of diode is used to connect the grid of enhanced pHemt pipe Q1 in low-noise amplifier, and the anode of diode is for connecting
The drain electrode of enhanced pHemt pipe Q1 in low-noise amplifier;When diode there are two or it is more than two when, all diodes are all
It is concatenated, wherein the anode of first diode is used to connect the drain electrode of enhanced pHemt pipe Q1 in low-noise amplifier,
The cathode of first diode connects the anode of second diode, and the cathode of the last one diode is put for connecting low noise
The grid of enhanced pHemt pipe Q1 in big device.
It further, further include first resistor R1;When diode only one when, one end of first resistor R1 connects diode
Cathode;When diode there are two or it is more than two when, one end of first resistor R1 connects the cathode of the last one diode;
The other end of first resistor R1 is for being grounded.It in this way can be by the positive temperature of the negative temperature characteristic of diode and first resistor R1 spy
Property complementation is got up, and is difficult to compensate for suitable temperature when preventing only with diode.And P1dB can also be improved.
It further, further include second resistance R2;When diode only one when, second resistance R2 and Diode series,
One end of the series circuit of two resistance R2 and diode composition is used to connect the leakage of enhanced pHemt pipe Q1 in low-noise amplifier
The other end of the series circuit of pole, second resistance R2 and diode composition is for connecting enhanced pHemt in low-noise amplifier
The grid of pipe Q1;When diode there are two or it is more than two when, second resistance R2 connects with all diodes, second resistance
One end of the series circuit of R2 and all diodes composition is used to connect the leakage of enhanced pHemt pipe Q1 in low-noise amplifier
Pole, second resistance R2 and the other end for the series circuit that all diodes form are enhanced in low-noise amplifier for connecting
The grid of pHemt pipe Q1.The positive temperature characterisitic complementation of the negative temperature characteristic of diode and second resistance R2 can be got up in this way,
Suitable temperature is difficult to compensate for when preventing only with diode.And P1dB can also be improved.
It further, further include 3rd resistor R3 and the first inductance L1;When diode only one when, the one of 3rd resistor R3
The cathode of end connection diode, the anode of one end connection diode of the first inductance L1;When diode there are two or two with
When upper, one end of 3rd resistor R3 connects the cathode of the last one diode, and one end of the first inductance L1 connects first two pole
The anode of pipe;The other end of 3rd resistor R3 is used to connect the grid of enhanced pHemt pipe Q1 in low-noise amplifier, the first electricity
The other end of sense L1 is used to connect the drain electrode of enhanced pHemt pipe Q1 in low-noise amplifier.It being capable of shape by 3rd resistor R3
At high-impedance state, direct current signal is prevented to be coupled to radio-frequency head.Direct current is prevented to believe by the perception that the first inductance L1 can use L1
Number it is coupled to radio frequency.
It further, further include first capacitor C1 and the second capacitor C2;When diode only one when, the one of first capacitor C1
The anode of end connection diode, the cathode of one end connection diode of the second capacitor C2;When diode there are two or two with
When upper, one end of first capacitor C1 connects the anode of first diode, and one end of the second capacitor C2 connects the last one two pole
The cathode of pipe;The other end of the other end of first capacitor C1 and the second capacitor C2 are used to be grounded.The first electricity can be passed through in this way
Hold C1 and the second capacitor C2 and filters out the electric current that DC terminal is coupled to radio-frequency head.
Using the low-noise amplifier of non-linear feedback circuit described in the utility model, including enhanced pHemt pipe Q1,
The grid of enhanced pHemt pipe Q1 connects at least one diode: when diode only one when, the cathode of diode, which connects, to be increased
The drain electrode of the grid of strong type pHemt pipe Q1, the anode of diode and enhanced pHemt pipe Q1 is all connected with one end of voltage source DC1;
When diode there are two or it is more than two when, the drain electrode of the anode and enhanced pHemt pipe Q1 of first diode is all connected with
One end of voltage source DC1, the cathode of first diode connect the anode of second diode, the cathode of the last one diode
The grid of link enhancement type pHemt pipe Q1;The source electrode of enhanced pHemt pipe Q1 and the other end of voltage source DC1 are grounded.
It further, further include first resistor R1;When diode only one when, one end of first resistor R1 connects diode
Cathode;When diode there are two or it is more than two when, one end of first resistor R1 connects the cathode of the last one diode;
The other end of first resistor R1 is grounded.It in this way can be mutual by the positive temperature characterisitic of the negative temperature characteristic of diode and first resistor R1
Benefit is got up, and is difficult to compensate for suitable temperature when preventing only with diode.And P1dB can also be improved.
It further, further include second resistance R2;When diode only one when, second resistance R2 and Diode series,
The one end for the series circuit that two resistance R2 are formed with diode connect the drain electrode of enhanced pHemt pipe Q1 in low-noise amplifier,
The other end for the series circuit that second resistance R2 is formed with diode connect the grid of enhanced pHemt pipe Q1 in low-noise amplifier
Pole;When diode there are two or it is more than two when, second resistance R2 connects with all diodes, second resistance R2 with own
The drain electrode of enhanced pHemt pipe Q1, second resistance R2 in one end connection low-noise amplifier of the series circuit of diode composition
The grid of enhanced pHemt pipe Q1 in low-noise amplifier is connect with the other end of the series circuit of all diodes composition.This
Sample can get up the positive temperature characterisitic complementation of the negative temperature characteristic of diode and second resistance R2, when preventing only with diode
It is difficult to compensate for suitable temperature.And P1dB can also be improved.
It further, further include 3rd resistor R3 and the first inductance L1;When diode only one when, the one of 3rd resistor R3
The cathode of end connection diode, the anode of one end connection diode of the first inductance L1;When diode there are two or two with
When upper, one end of 3rd resistor R3 connects the cathode of the last one diode, and one end of the first inductance L1 connects first two pole
The anode of pipe;The grid of the other end link enhancement type pHemt pipe Q1 of 3rd resistor R3, the other end of the first inductance L1, which connects, to be increased
The drain electrode of strong type pHemt pipe Q1.It is capable of forming high-impedance state by 3rd resistor R3, direct current signal is prevented to be coupled to radio-frequency head.
Direct current signal is prevented to be coupled to radio frequency by the perception that the first inductance L1 can use L1.
It further, further include first capacitor C1 and the second capacitor C2;When diode only one when, the one of first capacitor C1
The anode of end connection diode, the cathode of one end connection diode of the second capacitor C2;When diode there are two or two with
When upper, one end of first capacitor C1 connects the anode of first diode, and one end of the second capacitor C2 connects the last one two pole
The cathode of pipe;The other end of the other end of first capacitor C1 and the second capacitor C2 are grounded.First capacitor C1 can be passed through in this way
The electric current that DC terminal is coupled to radio-frequency head is filtered out with the second capacitor C2.
The utility model has the advantages that leading to the utility model discloses a kind of non-linear feedback circuit and using its low-noise amplifier
The negative temperature characteristic for crossing diode to carry out temperature-compensating to pHemt pipe Q1 enhanced in low-noise amplifier, to realize increasing
Benefit is stablized.In addition, the nonlinear characteristic by diode also can provide higher hamonic wave for low-noise amplifier, higher hamonic wave
Mutually offset the OIP3 that can be improved low-noise amplifier with addition.
Specific embodiment
The technical solution of the utility model is further introduced with attached drawing With reference to embodiment.
Fig. 1 is in the prior art using the circuit diagram of the power amplifier of temperature-compensation circuit, this temperature-compensation circuit
The variable condition of enhanced pHemt pipe Q21 can be allowed consistent with enhanced pHemt pipe Q11.When the temperature rises, enhanced
The electric current of pHemt pipe Q21 reduces, and the partial pressure fallen on the 4th resistance R4 reduces.At this time the Vds of enhanced pHemt pipe Q21 and
Vgs can be increased, and can inversely increase the electric current of enhanced pHemt pipe Q21, so that enhanced pHemt pipe Q21 electric current is protected in high/low temperature
It holds constant.Simultaneously enhanced pHemt pipe Q11 electric current also with the Vgs of enhanced pHemt pipe Q11 raising and remain unchanged.
But this temperature-compensation circuit in the prior art can not be used in low-noise amplifier, if being used in low-noise amplifier
In, then high/low temperature deviation can be bigger, and effect can be worse.
Therefore, present embodiment discloses a kind of non-linear feedback circuit, as shown in Fig. 2, include at least one two
Pole pipe;When diode only one when, the cathode of diode is used to connect the grid of enhanced pHemt pipe Q1 in low-noise amplifier
Pole, the anode of diode are used to connect the drain electrode of enhanced pHemt pipe Q1 in low-noise amplifier;When diode there are two or
When more than two, as in Fig. 2 D1, D2 ..., Dn, share n diode, n > 1, all diodes are connected in series,
In, the anode of first diode D1 is used to connect the drain electrode of enhanced pHemt pipe Q1 in low-noise amplifier, first two pole
The cathode of pipe D1 connects the anode of second diode D2, the cathode of the last one diode Dn is for connecting low-noise amplifier
In enhanced pHemt pipe Q1 grid.
This non-linear feedback circuit can also include first resistor R1, as shown in Figure 2;When diode only one when,
The cathode of one end connection diode of one resistance R1;When diode there are two or it is more than two when, one end of first resistor R1
Connect the cathode of the last one diode;The other end of first resistor R1 is for being grounded.
This non-linear feedback circuit can also include second resistance R2, as shown in Figure 2;When diode only one when,
One end of the series circuit of two resistance R2 and Diode series, second resistance R2 and diode composition is for connecting low noise amplification
The drain electrode of enhanced pHemt pipe Q1 in device, second resistance R2 are low for connecting with the other end for the series circuit that diode forms
The grid of enhanced pHemt pipe Q1 in noise amplifier;When diode there are two or it is more than two when, second resistance R2 and institute
There is diode to connect, one end of the series circuit of second resistance R2 and all diodes composition is for connecting low-noise amplifier
In enhanced pHemt pipe Q1 drain electrode, the other end of the series circuit that second resistance R2 is formed with all diodes is for connecting
The grid of enhanced pHemt pipe Q1 in low-noise amplifier.
This non-linear feedback circuit can also include 3rd resistor R3, as shown in Figure 2;When diode only one when,
The cathode of one end connection diode of three resistance R3;When diode there are two or it is more than two when, one end of 3rd resistor R3
Connect the cathode of the last one diode;The other end of 3rd resistor R3 is for connecting enhanced pHemt in low-noise amplifier
The grid of pipe Q1.
This non-linear feedback circuit can also include the first inductance L1, as shown in Figure 2;When diode only one when,
The anode of one end connection diode of one inductance L1;When diode there are two or it is more than two when, one end of the first inductance L1
Connect the anode of first diode;The other end of first inductance L1 is for connecting enhanced pHemt pipe in low-noise amplifier
The drain electrode of Q1.
This non-linear feedback circuit can also include first capacitor C1, as shown in Figure 2;When diode only one when,
The anode of one end connection diode of one capacitor C1;When diode there are two or it is more than two when, one end of first capacitor C1
Connect the anode of first diode;The other end of first capacitor C1 is for being grounded.
This non-linear feedback circuit can also include the second capacitor C2;When diode only one when, the second capacitor C2's
The cathode of one end connection diode;When diode there are two or it is more than two when, one end of the second capacitor C2 connects last
The cathode of a diode;The other end of second capacitor C2 is for being grounded.
Present embodiment also discloses the low-noise amplifier using above-mentioned non-linear feedback circuit, as shown in Fig. 2,
Including enhanced pHemt pipe Q1, the grid of enhanced pHemt pipe Q1 connects at least one diode: when diode only one
When, the grid of the cathode link enhancement type pHemt pipe Q1 of diode, the drain electrode of the anode of diode and enhanced pHemt pipe Q1
It is all connected with one end of voltage source DC1;When diode there are two or it is more than two when, the anode of first diode and enhanced
The drain electrode of pHemt pipe Q1 is all connected with one end of voltage source DC1, and the cathode of first diode connects the sun of second diode
Pole, the grid of the cathode link enhancement type pHemt pipe Q1 of the last one diode;The source electrode and voltage of enhanced pHemt pipe Q1
The other end of source DC1 is grounded.
This low-noise amplifier can also include first resistor R1, as shown in Figure 2;When diode only one when, first
The cathode of one end connection diode of resistance R1;When diode there are two or it is more than two when, one end of first resistor R1 connects
Connect the cathode of the last one diode;The other end of first resistor R1 is grounded.
This low-noise amplifier can also include second resistance R2, as shown in Figure 2;When diode only one when, second
Resistance R2 and Diode series, the one end for the series circuit that second resistance R2 and diode form, which is connect in low-noise amplifier, to be increased
The drain electrode of strong type pHemt pipe Q1, second resistance R2 connect low-noise amplifier with the other end for the series circuit that diode forms
In enhanced pHemt pipe Q1 grid;When diode there are two or it is more than two when, second resistance R2 and all diodes are equal
Series connection, second resistance R2 connect enhanced pHemt in low-noise amplifier with the one end for the series circuit that all diodes form
The drain electrode of pipe Q1, the other end for the series circuit that second resistance R2 and all diodes form, which is connect in low-noise amplifier, to be enhanced
The grid of type pHemt pipe Q1.
This low-noise amplifier can also include 3rd resistor R3, as shown in Figure 2;When diode only one when, third
The cathode of one end connection diode of resistance R3;When diode there are two or it is more than two when, one end of 3rd resistor R3 connects
Connect the cathode of the last one diode;The grid of the other end link enhancement type pHemt pipe Q1 of 3rd resistor R3.
This low-noise amplifier can also include the first inductance L1, as shown in Figure 2;When diode only one when, first
The anode of one end connection diode of inductance L1;When diode there are two or it is more than two when, one end of the first inductance L1 connects
Connect the anode of first diode;The drain electrode of the other end link enhancement type pHemt pipe Q1 of first inductance L1.
This low-noise amplifier can also include first capacitor C1, as shown in Figure 2;When diode only one when, first
The anode of one end connection diode of capacitor C1;When diode there are two or it is more than two when, one end of first capacitor C1 connects
Connect the anode of first diode;The other end of first capacitor C1 is grounded.
This low-noise amplifier can also include the second capacitor C2, as shown in Figure 2;When diode only one when, second
The cathode of one end connection diode of capacitor C2;When diode there are two or it is more than two when, one end of the second capacitor C2 connects
Connect the cathode of the last one diode;The other end of second capacitor C2 is grounded.
Certainly, this low-noise amplifier can also include the input matching circuit connecting with enhanced pHemt pipe Q1 grid,
It also may include the output matching circuit with enhanced pHemt pipe Q1 drain electrode connection, as shown in Figure 2.
Wherein, the number of diode can need to be adjusted according to actual circuit, so that circuit is generated suitable pressure drop, protect
Card wait at room temperature the Vg of enhanced pHemt pipe Q1 with it is desired identical.For example, a diode can provide the pressure of about 0.9V
Drop, as temperature increases, pressure drop can be reduced, and be changed about between 0.1V~0.2V, negative temperature characteristic is obvious.Second electricity
Resistance R2 temperature change be it is opposite with diode, with temperature increase resistance value will increase, namely offer pressure drop will increase, be
Positive temperature characterisitic.Also, the amplitude that the pressure drop of second resistance R2 varies with temperature is smaller, can rise to the temperature change of diode
To the effect of fine tuning and supplement.When design, pressure drop that can be as needed first substantially selects the quantity of diode, example
4 diodes are selected if 4V.It adds second resistance R2 to be finely adjusted and supplement, if discovery diode bring temperature-compensating
It is excessive, the quantity of diode can be deleted, the resistance value of second resistance R2 is increased.The resistance value of first resistor R1 can directly influence instead
The Vg of DC current and enhanced pHemt pipe Q1 on current feed circuit, needs to carry out coordination artificial debugging with second resistance R2.Emulation
When need variation with reference to OIP3, can extract voltage current waveform on the feed circuit, guarantee OIP3 in link tune
It equally also can achieve good compensation effect in section.
Fig. 3 is the relation curve of the gain and frequency in specific embodiment of the present invention under various situations.Wherein,
" without_-55 " indicates when not using first resistor R1, second resistance R2 and all diodes -55 DEG C of low-noise amplifiers
Gain, 25 DEG C of low noise amplifications when " without_25 " expression does not use first resistor R1, second resistance R2 and all diodes
The gain of device, 85 DEG C of low noises when " without_85 " expression does not use first resistor R1, second resistance R2 and all diodes
The gain of amplifier, " New_-55 " are indicated using -55 DEG C of low noises when first resistor R1, second resistance R2 and all diodes
The gain of amplifier, " New_25 " indicate to put using 25 DEG C of low noises when first resistor R1, second resistance R2 and all diodes
The gain of big device, " New_85 " are indicated using 85 DEG C of low noise amplifications when first resistor R1, second resistance R2 and all diodes
The gain of device, when temperature-compensation circuit in Fig. 1 is used -55 DEG C in low-noise amplifier by " Traditional_-55 " expression
The gain of low-noise amplifier, " Traditional_25 " expression use temperature-compensation circuit in Fig. 1 in low-noise amplifier
25 DEG C when low-noise amplifier gain, " Traditional_85 " indicates temperature-compensation circuit in Fig. 1 using low noise
The gain of low-noise amplifier when 85 DEG C in amplifier." Diode_-55 " expression does not use first resistor R1 and second resistance
R2, only with the gain of the low-noise amplifier of diode low-noise amplifier at -55 DEG C, " Diode_25 " expression is not used
First resistor R1 and second resistance R2, only with the gain of the low-noise amplifier of diode low-noise amplifier at 25 DEG C,
" Diode_85 " expression does not use first resistor R1 and second resistance R2, only with the low-noise amplifier of diode at 85 DEG C
The gain of low-noise amplifier.As it can be seen that when not using first resistor R1, second resistance R2 and all diodes, high/low temperature
Gain inequality is 1.2dB or so.When joined first resistor R1, second resistance R2 and all diodes, the gain inequality of high/low temperature
For 0.2dB or so, the consistency of low-noise amplifier gain in high/low temperature is largely maintained.It joined diode
When, the gain inequality of high/low temperature is 1dB or so.Temperature-compensation circuit in Fig. 1 is used in low-noise amplifier, the gain of high/low temperature
Difference is 2.5dB.It can be seen that low-noise amplifier is in height after joined first resistor R1, second resistance R2 and all diodes
The gain inequality of low temperature reduces very much.First resistor R1 and second resistance R2 are not used, when only with diode, low noise amplification
Device also reduces much in the gain inequality of high/low temperature.
Fig. 4 is the relation curve of the OIP3 and P1dB and frequency in specific embodiment of the present invention under various situations,
Low-noise amplifier when wherein " OIP3_Without " indicates not using first resistor R1, second resistance R2 and all diodes
OIP3, " OIP3_New " indicate the OIP3 using low-noise amplifier when first resistor R1, second resistance R2 and all diodes,
" OIP3_Diode " expression does not use first resistor R1 and second resistance R2, only with low-noise amplifier when diode
OIP3, low-noise amplifier when " P1dB_Without " expression does not use first resistor R1, second resistance R2 and all diodes
P1dB, " P1dB_New " indicates low-noise amplifier when using first resistor R1, second resistance R2 and all diodes
P1dB, " P1dB_Diode " expression does not use first resistor R1 and second resistance R2, only with low-noise amplifier when diode
P1dB.As it can be seen that when not using first resistor R1, second resistance R2 and all diodes, the output OIP3 of low-noise amplifier
For 26~28.7dBm or so, OIP3 ratio P1dB high 10dB.Using first resistor R1, second resistance R2 and all diodes it
Afterwards, the output OIP3 of low-noise amplifier is 31~33dBm or so, compared to not using first resistor R1, second resistance R2 and institute
3-7dB is increased when having diode, OIP3 ratio P1dB high 14dB has the promotion of highly significant.Do not use first resistor R1 and
Second resistance R2, when only with diode, the output OIP3 of low-noise amplifier is 26dBm or so, compared to not using the first electricity
OIP3 when hindering R1, second resistance R2 and all diodes is similar, and OIP3 ratio P1dB increases 14dB, mentions there has also been biggish
It rises.Simultaneously it can also be seen that the P1dB ratio P1dB_Diode of P1dB_New will be improved on high frequency after the addition of R1 and R2
8dB.Because if only using diode, do not have to R1 and R2, will lead to that there are many number of diodes, and parasitic capacitance value is excessive, generates appearance
Property feedback so that the P1dB of chip is reduced.