Broadband anti-burning anti-crosstalk annular low noise amplifier assembly

Abstract

The utility model relates to a broadband anti-burning anti-crosstalk annular low noise amplifier assembly, which comprises an input end, a low noise amplifier assembly and an output end, the input end is connected with a band-pass filter, and the output end is connected with a low-pass filter; the band-pass filter is connected with the low-noise amplifier assembly, and the low-pass filter is connected with the low-noise amplifier assembly through the down-conversion mixer; the low-noise amplifier assembly is of a multi-stage cascade system structure and comprises a front-stage broadband low-noise amplifier, a rear-stage SPDT radio frequency switch, a biasing circuit with temperature and voltage compensation effects and an ESD protection circuit. The front-stage broadband low-noise amplifier is cascaded with the rear-stage SPDT radio frequency switch; the front-stage broadband low-noise amplifier and the rear-stage SPDT radio frequency switch are respectively cascaded with a biasing circuit with temperature and voltage compensation effects; the utility model has the advantages of reasonable structure, strong anti-interference performance, safety and reliability, and can avoid burnout.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of low noise amplifier, concretely relates to wideband anti burning anti crosstalk annular low noise amplifier assembly. BACKGROUND

[0002] In recent years, with the rapid development of wireless communication technology, the requirements for receiver system are more and more strict, and the low noise amplifier is located at the first stage of the receiver, which is the key to determine the performance parameters such as sensitivity, dynamic range and anti-interference ability, in practical application, when a large number of signals are received by the antenna, the signals will saturate the circuit module at the back end of the mixer after passing through the low noise amplifier, resulting in that the receiver cannot work normally, since the low noise amplifier is usually used in the front end of the receiving end to amplify weak signals while introducing as little noise as possible, in radar or communication system, there may be a burst of high-power signals, which may cause the transistor to be burned out due to the input signal being too strong, resulting in that the amplifier is damaged, in addition, the existing low noise amplifier assembly has high integration, which may cause crosstalk from adjacent circuits or other parts in the same system, in addition, there may be interference between different channels or frequency bands, or interference caused by ground loop, resulting in that the low noise amplifier assembly cannot work normally, therefore, it is necessary to provide a wideband anti-burning anti-crosstalk annular low noise amplifier assembly which is reasonable in structure, avoids burning, strong in anti-interference, safe and reliable. SUMMARY

[0003] The utility model discloses a kind of wideband anti-burning anti-crosstalk annular low noise amplifier assemblies, to overcome the deficiencies of prior art, and provide a wideband anti-burning anti-crosstalk annular low noise amplifier assembly which is reasonable in structure, avoids burning, strong in anti-interference, safe and reliable.

[0004] The utility model discloses a kind of wideband anti-burning anti-crosstalk annular low noise amplifier assemblies, to overcome the deficiencies of prior art, and provide a wideband anti-burning anti-crosstalk annular low noise amplifier assembly which is reasonable in structure, avoids burning, strong in anti-interference, safe and reliable.

[0005] The input end is also provided with an input protection circuit.

[0006] The low noise amplifier component adopts 0.25um gate length GaAs PHEMT process transistor, wherein the front stage broadband low noise amplifier uses E-Mode transistor, and the rear stage SPDT radio frequency switch adopts D-Mode transistor.

[0007] The front stage broadband low noise amplifier adopts a resistance feedback type structure, and comprises a common source amplifier M1, a V out , a radio frequency choke inductor L D , a radio frequency inductor L bond , a stabilizing resistor R D , a source degeneration inductor L degen , and bypass capacitors C4 and C5.

[0008] The common source amplifier M1 adopts an E-Mode pHEMT transistor, the gate and the drain of which are connected through an LRC feedback network, the resistor R1 controls the gain and feedback depth, the inductor L1 controls the bandwidth of the circuit, and the capacitor C3 isolates the gate and the drain to prevent DC leakage.

[0009] The V out is supplied to the gate of the transistor M1 through a radio frequency signal blocking resistor R2 to prevent radio frequency signal from leaking from the gate bias circuit to deteriorate the noise and gain.

[0010] The radio frequency choke inductor L D prevents radio frequency signal from leaking from the drain bias circuit; meanwhile, the radio frequency choke inductor L D and the DC blocking capacitor C2 in the output signal path constitute an output matching network; the source degeneration inductor L degen is used to adjust the input impedance of the circuit, and together with the series matching inductor L g and the DC blocking capacitor C1, constitutes an input matching network.

[0011] The rear stage SPDT radio frequency switch is composed of a typical SPDT radio frequency switch circuit and a logic control circuit, and comprises: an antenna path RF in1 , an RF in2 path connected to the front stage broadband low noise amplifier, a radio frequency switch transistor M1, M2, a resistor R1, R3 in series at the gate of the transistor, a bias resistor R2, R4 between the drain and the source of the transistor, and logic control transistors M3, M4.

[0012] The bias circuit with temperature and voltage compensation function comprises three NMOS transistors M1, M2, M3 and a resistor R1 for temperature and voltage compensation; the gate and the drain of the M1 are connected together to form a common source diode; the drain of the M2 is connected to an external power supply voltage V reg through two resistors R1, R2 in series; and the gate of the M2 is connected to the drain of the M2 through R1.

[0013] The bias circuit with temperature and voltage compensation functions is further integrated with a current detection circuit module and a negative feedback regulation bias circuit.

[0014] The broadband anti-burning and anti-crosstalk annular low-noise amplifier assembly has the advantages that when the signal received by the antenna is weak, the signal is transmitted to the rear-end circuit through the internal amplifier; when the input signal is too strong, the signal can directly reach the rear-end circuit through the internal radio frequency switch, the problem that when a large number of input signals are received by the antenna, the signals are easy to saturate the circuit modules at all levels after the mixer after the low-noise amplifier, and the subsequent amplifier cannot work normally is solved; the annular low-noise amplifier assembly can be used in the frequency band of 400-700MHz, the input return loss is lower than -10dB, the noise coefficient is in the range of 0.85-1.05dB, the small signal gain is higher than 18dB, the input third-order intermodulation point is higher than 0dBm, the bypass switch insertion loss is in the range of -1.1 to -0.99dB, and the static power consumption current is kept at 10m4; the annular low-noise amplifier assembly has the advantages of reasonable structure, anti-burning, strong anti-interference performance, safety and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The utility model discloses a schematic diagram of the principle.

[0016] Figure 2 The utility model discloses the whole structure schematic diagram of the principle.

[0017] Figure 3 The utility model discloses the whole circuit diagram of the cascade system.

[0018] Figure 4 The utility model discloses the circuit topology drawing of the low noise amplifier of the front stage bandwidth.

[0019] Figure 5 The utility model discloses the SPDT radio frequency switch circuit structure diagram of the back stage.

[0020] Figure 6 The utility model discloses the bias circuit structure diagram with temperature, voltage compensation function. DETAILED DESCRIPTION

[0021] The utility model will be further explained in connection with the drawings.

[0022] Embodiment 1

[0023] As Figures 1-6As shown in the figure, the wideband burnout-resistant anti-crosstalk annular low-noise amplifier assembly comprises an input end, a low-noise amplifier assembly and an output end, the input end is connected with a band-pass filter BPF, and the output end is connected with a low-pass filter LPF; the band-pass filter is connected with the low-noise amplifier assembly, and the low-pass filter is connected with the low-noise amplifier assembly through a down-conversion mixer; the low-noise amplifier assembly adopts a multi-stage cascade system structure, and comprises a front-stage wideband low-noise amplifier, a rear-stage SPDT radio frequency switch, a bias circuit with temperature and voltage compensation effects and an ESD protection circuit (an integrated electrostatic discharge protection structure for preventing electrostatic breakdown of sensitive devices); the front-stage wideband low-noise amplifier is connected in cascade with the rear-stage SPDT radio frequency switch; and the front-stage wideband low-noise amplifier and the rear-stage SPDT radio frequency switch are connected in cascade with the bias circuit with temperature and voltage compensation effects, respectively.

[0024] The input end is further provided with an input protection circuit.

[0025] In the embodiment, the input protection circuit can adopt a limiter / clamping circuit: a limiting diode (such as a PIN diode) or a transient voltage suppressor (TVS) is added to the input end to limit the amplitude of the input signal and prevent overvoltage impact on the amplifier; the input protection circuit can also adopt an isolator / annular device: in a radar or high-power system, an isolator is used to absorb reverse power to avoid damage to the LNA caused by reflected signals.

[0026] The low-noise amplifier assembly adopts a 0.25um gate length GaAs PHEMT process transistor, wherein the front-stage wideband low-noise amplifier uses an enhancement-mode E-Mode transistor, and the rear-stage SPDT radio frequency switch uses a depletion-mode D-Mode transistor.

[0027] In the embodiment, the front-stage wideband low-noise amplifier and the rear-stage SPDT radio frequency switch are connected in cascade with a system circuit structure as shown in the figure. Figure 3 M1 is a low-noise amplifier transistor, and M2 and M3 are radio frequency switch transistors; the drain of M2 is connected with the drain of M1, the drain of M3 is connected with the gate of M1, and the constant bias circuit of M1 is connected with a power supply voltage V bias of the logic circuit of M2 and M3 (not shown in the figure); in this way, when V bias = 0V, V bias1 = 0V, V bias2 = 3.3V, M1 and M2 are cut off, M3 is turned on, the input signal does not pass through the wideband low-noise amplifier and directly flows out from the radio frequency switch; when V bias = 3.3V, V bias1 = 3.3V, V bias2=0V, M1, M2 are on, M3 is off, the input signal is amplified by the amplifier first and then output from the switch. The following will be described respectively for the front stage wideband low noise amplifier and the rear stage SPDT radio frequency switch.

[0028] The front stage wideband low noise amplifier adopts the structure based on resistance feedback, including common source amplifier M1, V out , radio frequency choke inductor L D , radio frequency inductor L bond , stable resistance R D (reselective addition according to actual situation), source degeneration inductor L degen and bypass capacitor C4 and C5 for filtering bias power supply noise.

[0029] The common source amplifier M1 adopts E-Mode pHEMT transistor, the gate and the drain thereof are connected through LRC feedback network, resistance R1 controls the gain and feedback depth, inductor L1 controls the bandwidth of the circuit, capacitor C3 isolates the gate and the drain, preventing direct current leakage.

[0030] The V out is powered by the gate of transistor M1 through radio frequency signal blocking resistance R2, the resistance R2 needs to be large enough (>1000Ω) to prevent radio frequency signal from leaking from the gate bias circuit to deteriorate the noise and gain.

[0031] The radio frequency choke inductor L D avoids radio frequency signal from leaking from the drain bias circuit to affect the gain and linearity index; at the same time, the radio frequency choke inductor L D and the output signal path form the output matching network with the direct current isolation capacitor C2; the source degeneration inductor L degen is used for adjusting the input impedance of the circuit, and together with the series matching inductor L g and the direct current isolation capacitor C1 forms the input matching network.

[0032] The rear stage SPDT radio frequency switch is composed of the typical SPDT radio frequency switch circuit with the addition of logic control circuit, including: coupling antenna path RF in1 , coupling the RF in2 of the front stage wideband low noise amplifier path, radio frequency switch transistor M1, M2, resistance R1, R3 in series at the gate of the transistor, bias resistance R2, R4 between the drain and the source of the transistor, logic control transistor M3, M4.

[0033] In the embodiment, the rear-stage SPDT radio frequency switch circuit adopts GaAs pHEMT with 0.25um gate length, depletion mode transistor; the switch works in passive state, and the on-off of the pass is controlled by the gate-source potential difference; meanwhile, the switch circuit only produces weak DC power consumption, and has no influence on the overall power consumption; and the pHEMT has low insertion loss and high linearity physical characteristics, and will not deteriorate the overall noise coefficient and linearity performance.

[0034] The topology structure of the rear-stage SPDT radio frequency switch circuit is shown in Figure 5 The RF in1 is connected to the antenna pass, when the received signal energy of the antenna is very high, the signal does not need to be amplified by the amplifier, and can directly pass through the branch to enter the rear-stage mixer; the RF in2 is connected to the front-stage wideband low noise amplifier pass, when the received signal energy of the antenna is very low, the signal is amplified first and then enters the rear-stage mixer. Wherein, M1 and M2 are radio frequency switch transistors; R1 and R3 are transistor gate series resistors; R2 and R4 are transistor drain and source bias resistors; M3 and M4 are logic control transistors; when V bias =0V, M3 in the logic circuit is turned on, M4 is turned off, thus M1 in the switch circuit is turned on, M2 is turned off, and Branch-1 is connected; on the contrary, when V bias =3.3V, Branch-2 is connected. The bias resistors R2 and R4 are used for stabilizing the DC bias of the radio frequency switch; the gate series resistors R1 and R3 are used for isolating the bias voltage and the radio frequency signal; the resistors R5, R6, R7 and R8 in the logic circuit control the switch speed, if the value is too large, the speed will be slow; if the value is too small, the circuit power consumption will increase; when the resistor values are R2=R4=R5=R6=40kΩ, R1=R3=R7=R8=20kΩ, the best switch performance is obtained.

[0035] The utility model discloses a broadband anti-burnout anti-crosstalk annular low noise amplifier assembly, in use, the utility model discloses a bypass switch function is integrated in the low noise amplifier assembly inside, namely when the signal weak that antenna receives, signal transmission to rear end circuit through internal amplifier, and when input signal is too strong, can directly reach rear end circuit through internal radio frequency switch, effectively solve when the antenna receives a big quantity order input signal, the signal after low noise amplifier, easy make the saturation of each stage circuit module after mixer, lead to the problem of subsequent amplifier unable normal work, the utility model discloses can be in 400~700MHz frequency band, input return loss is less than -10dB, noise factor is in 0.85~1.05dB range, small signal gain is higher than 18dB, input third order intermodulation point is higher than 0dBm, bypass switch insertion loss is in -1.1~-0.99dB range, static power consumption current keeps at 10m4, the utility model discloses have the advantages of reasonable structure, avoid burning, strong anti -interference, safe and reliable.

[0036] Example 2

[0037] As Figures 1-6 shown, broadband anti-burnout anti-crosstalk annular low noise amplifier assembly, it includes input, low noise amplifier assembly and output, the input is connected with band pass filter, the output is connected with low pass filter, the band pass filter is connected with low noise amplifier assembly, the low pass filter is connected with low noise amplifier assembly through down conversion mixer, the low noise amplifier assembly adopts multistage cascade system structure, including: front stage broadband low noise amplifier, back stage SPDT radio frequency switch, bias circuit with temperature, voltage compensation effect, ESD protection circuit, the front stage broadband low noise amplifier is connected in cascade with back stage SPDT radio frequency switch, the front stage broadband low noise amplifier, back stage SPDT radio frequency switch are connected in cascade with bias circuit with temperature, voltage compensation effect respectively.

[0038] The bias circuit with temperature, voltage compensation effect includes three NMOS transistors M1, M2, M3 and resistance R1 for temperature, voltage compensation, the M1 gate and drain are connected together and constitute a common source stage diode, have the effect of voltage clamping, the drain of M2 is connected to the external supply voltage V reg through two resistances R1, R2 in series, the gate of M2 is connected to the drain of itself through R1, M3 is a typical source follower structure, the gain is approximately 1, increase output capacity, so that V b =V out .

[0039] In the embodiment, the bias circuit with temperature, voltage compensation effect structure is as shown in Figure 6 M1, M2 work in saturation zone, when V reg decreases, I1 also decreases, because M1, M2 gate voltage Also decreases, however, the amount of decrease can be compensated by the voltage drop across R1; conversely, V reg increases, the amount of increase can be compensated by the voltage increase across R1; by keeping V b approximately constant, V out has a stable bias voltage output.

[0040] When the external temperature decreases, because the transistor threshold voltage V TH increases, the currents I1, I2 decrease, the M2 gate voltage increases, the voltage across R1 decreases, the M2 gate voltage V b increases, effectively compensating for the magnitude of the decrease in I2; when the temperature increases, the same applies, through the compensating effect of R1, weakening the influence of temperature on V out .

[0041] In the circuit structure, M1, M2, M3 are selected to be the same size, when the external supply voltage V reg changes ΔV, the current I1 changes ΔI1, the gate-source voltage of M1 and M2 each changes ΔV gs , the gate voltage of M3 V b changes ΔV b , which can be written as: ΔV = ΔI1·R2 + 2·ΔV gs (1), ΔV b = [(V reg + ΔV) - (I1 + ΔI1)·(R1 + R2)] - [V reg - I1·(R1 + R2)] (2), ΔV b = ΔV - ΔI1·(R1 + R2) (3), substituting equation (1) into equation (3), ΔV b can be written as: ΔV b = 2·ΔV gs - ΔI1·R1 (4), therefore, by reasonably selecting R1, the influence of the external bias voltage on V b can be compensated, making ΔV b approximately 0.

[0042] The bias circuit with temperature and voltage compensation also integrates a current detection circuit module and a negative feedback adjustment bias circuit.

[0043] In this embodiment, overcurrent protection: a current detection module is added to the bias circuit, which automatically cuts off or adjusts the bias voltage when the current exceeds the threshold; temperature compensation: the low-noise amplifier component temperature is monitored and the bias is adjusted through negative feedback to avoid overheating and burning.

[0044] In actual use, the low-noise amplifier assembly adopts a high-thermal-conductivity substrate (such as aluminum nitride ceramic) and reduces reflected power through good impedance matching to avoid local hot spots caused by standing waves and achieve an anti-burning function.

[0045] The low-noise amplifier assembly uses a metal shield to isolate the LNA (low-noise amplifier) from other high-frequency circuits (such as mixers and local oscillators) to achieve electromagnetic shielding; it can also be isolated through physical layout: physically isolating sensitive circuits from high-power transmission channels, digital circuits, and the like to reduce coupling paths. Bandpass filters / low-pass filters are added at the input / output ends to suppress out-of-band interference signals (such as adjacent frequency signals and harmonics); star grounding / layered grounding is used in grounding and wiring optimization: to avoid common ground impedance coupling, an independent ground layer is used to separate analog and digital grounds to achieve an anti-crosstalk function.

[0046] The utility model discloses a broadband anti-burning anti-crosstalk annular low noise amplifier assembly, in use, the utility model discloses a bypass switch function is integrated in the low noise amplifier assembly, namely when the signal received by the antenna is weak, the signal is transmitted to the rear end circuit through the internal amplifier, and when the input signal is too strong, can directly reach the rear end circuit through the internal radio frequency switch, effectively solve when the antenna receives a big quantity order input signal, the signal after low noise amplifier, easily make the saturation of each circuit module after mixer, lead to the problem of subsequent amplifier can not work normally, the utility model discloses can be in 400~700MHz frequency band, input return loss is less than -10dB, noise figure is in 0.85~1.05dB range, small signal gain is higher than 18dB, input third order intercept point is higher than 0dBm, bypass switch insertion loss is in -1.1~-0.99dB range, static power consumption current keeps at 10m4, the utility model discloses have the advantages of reasonable structure, avoid burning, strong anti-interference, safe and reliable.

Claims

1. A broadband burnout-resistant, crosstalk-immune, annular low-noise amplifier assembly comprising an input, a low-noise amplifier assembly, and an output, characterized by: The input end is connected with a band-pass filter, and the output end is connected with a low-pass filter; the band-pass filter is connected with a low-noise amplifier assembly, and the low-pass filter is connected with the low-noise amplifier assembly through a down-conversion frequency mixer; the low-noise amplifier assembly adopts a multi-stage cascade system structure, and comprises a front-stage broadband low-noise amplifier, a rear-stage SPDT radio frequency switch, a bias circuit with temperature and voltage compensation effects, and an ESD protection circuit; the front-stage broadband low-noise amplifier is connected in cascade with the rear-stage SPDT radio frequency switch; and the front-stage broadband low-noise amplifier and the rear-stage SPDT radio frequency switch are connected in cascade with the bias circuit with temperature and voltage compensation effects, respectively.

2. The broadband burnout-resistant, anti-crosstalk, annular low-noise amplifier assembly of claim 1, wherein: The input end is further provided with an input protection circuit.

3. The broadband burnout-resistant, alien crosstalk-free, annular low-noise amplifier assembly of claim 1, wherein: The low-noise amplifier assembly adopts a 0.25um gate length GaAs PHEMT process transistor, wherein the front-stage broadband low-noise amplifier uses an E-Mode transistor, and the rear-stage SPDT radio frequency switch uses a D-Mode transistor.

4. The broadband burnout-resistant, crosstalk-immune, annular low-noise amplifier assembly of claim 3, wherein: The front-stage broadband low-noise amplifier adopts a resistance feedback type structure, comprising a common-source amplifier M1, V out , a radio frequency choke inductor L D , a radio frequency inductor L bond , a stabilizing resistor R D , a source degeneration inductor L degen , and bypass capacitors C4 and C5.

5. The broadband burnout-resistant, alien crosstalk-free, annular low-noise amplifier assembly of claim 4, wherein: The common source amplifier M1 adopts an E-Mode pHEMT transistor, the gate and the drain of which are connected through an LRC feedback network, the resistance R1 controls the gain and the feedback depth, the inductance L1 controls the bandwidth of the circuit, and the capacitance C3 isolates the gate and the drain to prevent DC leakage.

6. The broadband burnout-resistant, alien crosstalk-free, annular low-noise amplifier assembly of claim 4, wherein: The V out The gate of transistor Ml is powered through a radio frequency signal blocking resistor R2 to prevent radio frequency signal leakage from the gate bias circuit which would otherwise degrade noise and gain.

7. The broadband burnout-proof anti-crosstalk annular low-noise amplifier assembly of claim 4, wherein: The radio frequency choke inductance L D Avoids the radio frequency signal from leaking from the drain bias circuit; meanwhile, the radio frequency choke inductance L D And the output matching network is composed of the drain bias circuit, the output signal path and the blocking capacitor C2 The source degeneration inductance L degen for adjusting the input impedance of the circuit while matching the series inductance L g and the blocking capacitor C1 together form an input matching network.

8. The broadband burnout-resistant, alien crosstalk-free, annular low-noise amplifier assembly of claim 3, wherein: The rear-stage SPDT radio frequency switch is composed of a typical SPDT radio frequency switch circuit and a logic control circuit, and includes: an antenna path RF in1 , an RF in2 path connected with the front-stage wideband low-noise amplifier, radio frequency switch transistors M1 and M2, transistor gate series resistors R1 and R3, transistor drain-source bias resistors R2 and R4, and logic control transistors M3 and M4.

9. The broadband burnout-resistant, alien crosstalk-free, annular low-noise amplifier assembly of claim 1, wherein: The bias circuit with temperature and voltage compensation comprises three NMOS transistors M1, M2 and M3 and a resistance R1 for temperature and voltage compensation; the gate and the drain of the M1 are connected together to form a common-source stage diode; the drain of the M2 is connected to an external power supply voltage V reg through two resistances R1 and R2 in series; the gate of the M2 is connected to the drain of the M2 through the R1.

10. The broadband burnout-resistant, crosstalk-immune, annular low-noise amplifier assembly of claim 9, wherein: The bias circuit with temperature and voltage compensation effects is further integrated with a current detection circuit module and a negative feedback adjusting bias circuit.

Images