阅读说明：本技术 控制电路和低噪声放大器 (Control circuit and low noise amplifier ) 是由 张晓朋 曲韩宾 高博 王文娟 赵亚 谷江 于 2019-10-21 设计创作，主要内容包括：本发明属于射频芯片设计技术领域,涉及一种控制电路和低噪声放大器,包括差分比较模块、电平转移模块和开关模块；差分比较模块接收外部信号设备的电平信号,在电平信号的电压小于参考电压时向电平转移模块发送第一截止信号,或,在电平信号的电压大于或等于参考电压时向电平转移模块发送第一导通信号；电平转移模块根据第一截止信号截止并输出第二截止信号,或将第一导通信号进行电平转移得到第二导通信号；开关模块根据第二截止信号截止以控制外部低噪声放大器工作,或根据第二导通信号导通以控制外部低噪声放大器关断。本发明可以使低噪声放大器应用在时分双工模式下,功耗低,开关速度快,抗干扰能力强。(The invention belongs to the technical field of radio frequency chip design, and relates to a control circuit and a low noise amplifier, which comprise a differential comparison module, a level transfer module and a switch module; the differential comparison module receives a level signal of external signal equipment, and sends a first cut-off signal to the level transfer module when the voltage of the level signal is less than a reference voltage, or sends a first conduction signal to the level transfer module when the voltage of the level signal is greater than or equal to the reference voltage; the level transfer module cuts off and outputs a second cut-off signal according to the first cut-off signal, or carries out level transfer on the first conducting signal to obtain a second conducting signal; the switch module is turned off according to the second turn-off signal to control the external low noise amplifier to work, or turned on according to the second turn-on signal to control the external low noise amplifier to turn off. The invention can make the low noise amplifier applied in the time division duplex mode, and has low power consumption, fast switching speed and strong anti-interference capability.)

1. A control circuit, comprising: the circuit comprises a differential comparison module, a level transfer module and a switch module; the input end of the differential comparison module is suitable for being connected with external signal equipment, the voltage end of the differential comparison module is suitable for being connected with an external power supply, and the output end of the differential comparison module is connected with the input end of the level shift module; the voltage end of the level transfer module is suitable for being connected with an external power supply, and the output end of the level transfer module is connected with the input end of the switch module; the output end of the switch module is suitable for being connected with an external low noise amplifier;

the differential comparison module is used for receiving a level signal of an external signal device and sending a first cut-off signal to the level shift module when the voltage of the level signal is smaller than a reference voltage, or sending a first conduction signal to the level shift module when the voltage of the level signal is larger than or equal to the reference voltage;

the level shift module is used for stopping according to the first stopping signal and sending a second stopping signal to the switch module when the received signal is a first stopping signal, or carrying out level shift on the first conducting signal to obtain a second conducting signal and sending the second conducting signal to the switch module when the received signal is a first conducting signal;

the switch module is used for switching off according to the second cut-off signal when the received signal is the second cut-off signal so as to control the external low noise amplifier to work, or switching on according to the second switching-on signal when the received signal is the second switching-on signal so as to control the external low noise amplifier to be switched off.

2. The control circuit of claim 1, wherein the differential comparison module comprises: the circuit comprises a first resistor, a second resistor, a third resistor, a bias resistor, a differential amplification unit and a first voltage division unit;

the first end of the first resistor is connected with the input end of the differential comparison module, and the second end of the first resistor is connected with the first end of the differential amplification unit;

a second end of the differential amplification unit is connected with a first end of the second resistor, a third end of the differential amplification unit is connected with a first end of the third resistor and an output end of the differential comparison module, a fourth end of the differential amplification unit is connected with a first end of the bias resistor, and a fifth end of the differential amplification unit is connected with a first end of the first voltage division unit;

the second end of the second resistor, the second end of the third resistor and the second end of the first voltage division unit are connected with the voltage end of the differential comparison module, and the third end of the first voltage division unit and the second end of the bias resistor are grounded.

3. The control circuit according to claim 2, wherein the differential amplifying unit includes: a first transistor, a second transistor, and a fourth resistor;

the grid electrode of the first transistor is connected with the first end of the differential amplification unit, the drain electrode of the first transistor is connected with the second end of the differential amplification unit, and the source electrode of the first transistor is connected with the fourth end of the differential amplification unit; the grid electrode of the second transistor is connected with the first end of the fourth resistor, the drain electrode of the second transistor is connected with the third end of the differential amplification unit, and the source electrode of the second transistor is connected with the fourth end of the differential amplification unit; and the second end of the fourth resistor is connected with the fifth end of the differential amplification unit.

4. The control circuit of claim 2, wherein the first voltage division unit comprises: a fifth resistor and a sixth resistor;

the first end of the fifth resistor is connected with the first end of the first voltage division unit and the first end of the sixth resistor, and the second end of the fifth resistor is connected with the second end of the first voltage division unit; and the second end of the sixth resistor is connected with the third end of the first voltage division unit.

5. The control circuit of any of claims 1 to 4, wherein the level shift module comprises: a third transistor, a second voltage division unit and a seventh resistor;

a gate of the third transistor is connected to an input terminal of the level shift module, a drain of the third transistor is connected to a voltage terminal of the level shift module, and a source of the third transistor is connected to an input terminal of the second voltage divider and a first terminal of the seventh resistor; the output end of the second voltage division unit is connected with the output end of the level transfer module; and the second end of the seventh resistor is grounded.

6. The control circuit of claim 5, wherein the second voltage division unit comprises: a fourth transistor;

and the grid electrode of the fourth transistor is connected with the input end of the second voltage division unit, and the source electrode and the drain electrode of the fourth transistor are both connected with the output end of the second voltage division unit.

7. The control circuit of claim 5, wherein the second voltage division unit comprises: a Schottky diode;

the positive pole of the Schottky diode is connected with the input end of the second voltage division unit, and the negative pole of the Schottky diode is connected with the output end of the second voltage division unit.

8. The control circuit of any of claims 1 to 4, wherein the switch module comprises: a fifth transistor, a first capacitor and an eighth resistor;

a first end of the eighth resistor is connected with the input end of the switch module, and a second end of the eighth resistor is connected with both the gate of the fifth transistor and the first end of the first capacitor; the drain electrode of the fifth transistor is connected with the output end of the switch module, and the source electrode of the fifth transistor and the second end of the first capacitor are both grounded.

9. The control circuit of claim 8, wherein the switch module further comprises: a ninth resistor;

the first end of the ninth resistor is connected with the grid electrode of the fifth transistor, and the second end of the ninth resistor is grounded.

10. A low noise amplifier comprising a low noise amplification chip, characterized by comprising the control circuit according to any one of claims 1 to 9 connected to the low noise amplification chip.

Technical Field

The invention belongs to the technical field of radio frequency chip design, and particularly relates to a control circuit and a low noise amplifier.

Background

In recent years, with the rapid development of wireless communication, especially with the arrival of fifth generation mobile communication, people have an increasing demand for realizing comprehensive coverage of mobile communication signals, so that a large number of small base stations are required to be laid for shunting to solve communication pressure, and a low noise amplifier is taken as an important device in a fifth generation mobile communication system, and is further required to be upgraded and updated to adapt to development demands of low power consumption, high integration, multiple functions and the like. However, the conventional low noise amplifier has problems of high power consumption and the like.

Disclosure of Invention

In view of this, embodiments of the present invention provide a control circuit and a low noise amplifier to solve the problem of high power consumption of the low noise amplifier in the prior art.

A first aspect of an embodiment of the present invention provides a control circuit, including: the circuit comprises a differential comparison module, a level transfer module and a switch module; the input end of the differential comparison module is suitable for being connected with external signal equipment, the voltage end of the differential comparison module is suitable for being connected with an external power supply, and the output end of the differential comparison module is connected with the input end of the level shift module; the voltage end of the level transfer module is suitable for being connected with an external power supply, and the output end of the level transfer module is connected with the input end of the switch module; the output end of the switch module is suitable for being connected with an external low noise amplifier;

the differential comparison module is used for receiving a level signal of an external signal device and sending a first cut-off signal to the level shift module when the voltage of the level signal is smaller than a reference voltage, or sending a first conduction signal to the level shift module when the voltage of the level signal is larger than or equal to the reference voltage;

the level shift module is used for stopping according to the first stopping signal and sending a second stopping signal to the switch module when the received signal is a first stopping signal, or carrying out level shift on the first conducting signal to obtain a second conducting signal and sending the second conducting signal to the switch module when the received signal is a first conducting signal;

the switch module is used for switching off according to the second cut-off signal when the received signal is the second cut-off signal so as to control the external low noise amplifier to work, or switching on according to the second switching-on signal when the received signal is the second switching-on signal so as to control the external low noise amplifier to be switched off.

Optionally, the differential comparing module includes: the circuit comprises a first resistor, a second resistor, a third resistor, a bias resistor, a differential amplification unit and a first voltage division unit;

the first end of the first resistor is connected with the input end of the differential comparison module, and the second end of the first resistor is connected with the first end of the differential amplification unit;

a second end of the differential amplification unit is connected with a first end of the second resistor, a third end of the differential amplification unit is connected with a first end of the third resistor and an output end of the differential comparison module, a fourth end of the differential amplification unit is connected with a first end of the bias resistor, and a fifth end of the differential amplification unit is connected with a first end of the first voltage division unit;

the second end of the second resistor, the second end of the third resistor and the second end of the first voltage division unit are connected with the voltage end of the differential comparison module, and the third end of the first voltage division unit and the second end of the bias resistor are grounded.

Optionally, the differential amplifying unit includes: a first transistor, a second transistor, and a fourth resistor;

the grid electrode of the first transistor is connected with the first end of the differential amplification unit, the drain electrode of the first transistor is connected with the second end of the differential amplification unit, and the source electrode of the first transistor is connected with the fourth end of the differential amplification unit; the grid electrode of the second transistor is connected with the first end of the fourth resistor, the drain electrode of the second transistor is connected with the third end of the differential amplification unit, and the source electrode of the second transistor is connected with the fourth end of the differential amplification unit; and the second end of the fourth resistor is connected with the fifth end of the differential amplification unit.

Optionally, the first voltage division unit includes: a fifth resistor and a sixth resistor;

the first end of the fifth resistor is connected with the first end of the first voltage division unit and the first end of the sixth resistor, and the second end of the fifth resistor is connected with the second end of the first voltage division unit; and the second end of the sixth resistor is connected with the third end of the first voltage division unit.

Optionally, the level shift module includes: a third transistor, a second voltage division unit and a seventh resistor;

a gate of the third transistor is connected to an input terminal of the level shift module, a drain of the third transistor is connected to a voltage terminal of the level shift module, and a source of the third transistor is connected to an input terminal of the second voltage divider and a first terminal of the seventh resistor; the output end of the second voltage division unit is connected with the output end of the level transfer module; and the second end of the seventh resistor is grounded.

Optionally, the second voltage division unit includes: a fourth transistor;

and the grid electrode of the fourth transistor is connected with the input end of the second voltage division unit, and the source electrode and the drain electrode of the fourth transistor are both connected with the output end of the second voltage division unit.

Optionally, the second voltage division unit includes: a Schottky diode;

the positive pole of the Schottky diode is connected with the input end of the second voltage division unit, and the negative pole of the Schottky diode is connected with the output end of the second voltage division unit.

Optionally, the switch module includes: a fifth transistor, a first capacitor and an eighth resistor;

a first end of the eighth resistor is connected with the input end of the switch module, and a second end of the eighth resistor is connected with both the gate of the fifth transistor and the first end of the first capacitor; the drain electrode of the fifth transistor is connected with the output end of the switch module, and the source electrode of the fifth transistor and the second end of the first capacitor are both grounded.

Optionally, the switch module further includes: a ninth resistor;

the first end of the ninth resistor is connected with the grid electrode of the fifth transistor, and the second end of the ninth resistor is grounded.

A second aspect of an embodiment of the present invention provides a low noise amplifier, including a low noise amplification chip, and further including a control circuit, which is connected to the low noise amplification chip, as described in any one of the first aspect of the embodiments.

Compared with the prior art, the control circuit and the low-noise amplifier in the embodiment of the invention have the beneficial effects that: the circuit mainly comprises a differential comparison module, a level transfer module and a switch module, and has the advantages of simple structure, small size and easy control; the differential comparison module sends a first cut-off signal to the level shift module when the voltage of the level signal is less than the reference voltage, or sends a first turn-on signal to the level shift module when the voltage of the level signal is greater than or equal to the reference voltage; the level transfer module is cut off according to the first cut-off signal or carries out level transfer on the first conducting signal, so that output crosstalk or distortion of the circuit caused by power supply noise is avoided, and the anti-interference capability is strong; the switch module is switched off according to the second cut-off signal to control the external low noise amplifier to work, or is switched on according to the second conduction signal to control the external low noise amplifier to be switched off, so that the low noise amplifier can be applied to a time division duplex mode, the power consumption is low, and the switching speed is high.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of a control circuit according to an embodiment of the present invention;

FIG. 2 is a circuit diagram of a control circuit according to an embodiment of the present invention;

fig. 3 is a schematic diagram illustrating a relationship between a voltage of a level signal and an output voltage according to an embodiment of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, a control circuit according to an embodiment of the present invention mainly includes: a differential comparison module 100, a level shift module 200 and a switch module 300; the input end of the differential comparison module 100 is suitable for being connected with an external signal device, the voltage end of the differential comparison module 100 is suitable for being connected with an external power supply VDD, and the output end of the differential comparison module 100 is connected with the input end of the level shift module 200; the voltage end of the level shift module 200 is suitable for being connected with an external power supply VDD, and the output end of the level shift module 200 is connected with the input end of the switch module 300; the output of the switching module 300 is adapted to be connected to a bias circuit of an external low noise amplifier.

The differential comparison module 100 receives a level signal of an external signal device, and sends a first cut-off signal to the level shift module 200 when the voltage of the level signal is less than a reference voltage, the level shift module 200 cuts off according to the first cut-off signal and sends a second cut-off signal to the switch module 300 when the received signal is the first cut-off signal, and the switch module 300 cuts off according to the second cut-off signal when the received signal is the second cut-off signal, so as to control the external low noise amplifier to operate.

Or, the differential comparison module 100 receives a level signal of an external signal device, and sends a first conduction signal to the level shift module 200 when the voltage of the level signal is greater than or equal to a reference voltage, the level shift module 200 performs level shift on the first conduction signal to obtain a second conduction signal and sends the second conduction signal to the switch module 300 when the received signal is the first conduction signal, and the switch module 300 is turned on according to the second conduction signal when the received signal is the second conduction signal to control the external low noise amplifier to be turned off.

In the field of low noise amplifiers, the enhanced PHEMT of gallium arsenide materials has great advantages, manufacturers at home and abroad mainly concentrate on the enhanced PHEMT process for high-performance low noise amplifier products at present, and one of working frequency bands of a fifth-generation mobile communication system is a sub 6G frequency band, in the frequency band, the enhanced PHEMT process of gallium arsenide materials has low noise coefficient, can provide high gain, has high linearity and transconductance, only needs a single power supply for power supply, and meets the requirement of designing low noise amplifiers.

However, the conventional low noise amplifier focuses mainly on low noise and high gain, and neglects low power consumption, so as to ensure that the overall system has lower power consumption, the low noise amplifier is required to have an enable-and-turn-off function. However, the enabling and shutting circuit based on the gallium arsenide process is very difficult to implement because the enhanced PHEMT of the gallium arsenide material only has one type of active device, cannot form a complementary gate circuit, and is limited by the lower threshold voltage of the enhanced PHEMT, and it is not easy to manufacture a control circuit with accurate threshold voltage.

In view of the above problems, the present embodiment provides a control circuit applicable to a low noise amplifier of a fifth generation mobile communication base station, wherein a turn-off function is integrated in the low noise amplifier, the control can be performed under a TTL logic level, the anti-interference capability is strong, and by turning off a receiving channel of the low noise amplifier in real time, the low noise amplifier can be applied in a time division duplex mode, the switching speed is high, and the control circuit has a certain application value in a base station receiving system.

The control circuit has the advantages of simple structure, small size and easy control; the differential comparison module 100 outputs a turn-on or turn-off signal through differential comparison of the level signal; the level transfer module 200 transfers the level of the cut-off signal or the conducting signal, so that the output crosstalk or distortion of the circuit caused by power supply noise is avoided, and the anti-interference capability is strong; the switching module 300 controls the external low noise amplifier to operate or turn off according to the turn-off signal or the turn-on signal, so that the low noise amplifier can be applied in the time division duplex mode and has a fast switching speed.

In one embodiment, referring to fig. 2, the differential comparison module 100 may include: a first resistor R1, a second resistor R2, a third resistor R3, a bias resistor Rb, a differential amplifying unit 110, and a first voltage dividing unit 120. A first terminal of the first resistor R1 is connected to the input terminal of the differential comparison module 100, and a second terminal of the first resistor R1 is connected to the first terminal of the differential amplification unit 110. A second end of the differential amplifying unit 110 is connected to a first end of the second resistor R2, a third end of the differential amplifying unit 110 is connected to a first end of the third resistor R3 and an output end of the differential comparing module 100, a fourth end of the differential amplifying unit 110 is connected to a first end of the bias resistor Rb, and a fifth end of the differential amplifying unit 110 is connected to a first end of the first voltage dividing unit 120; the second terminal of the second resistor R2, the second terminal of the third resistor R3, and the second terminal of the first voltage divider unit 120 are all connected to the voltage terminal of the differential comparison module 100, and the third terminal of the first voltage divider unit 120 and the second terminal of the bias resistor Rb are all grounded.

Alternatively, the differential amplifying unit 110 may include: a first transistor E1, a second transistor E2, and a fourth resistor R4; the gate of the first transistor E1 is connected to the first terminal of the differential amplification unit 110, the drain of the first transistor E1 is connected to the second terminal of the differential amplification unit 110, and the source of the first transistor E1 is connected to the fourth terminal of the differential amplification unit 110; a gate of the second transistor E2 is connected to the first end of the fourth resistor R4, a drain of the second transistor E2 is connected to the third end of the differential amplification unit 110, and a source of the second transistor E2 is connected to the fourth end of the differential amplification unit 110; a second terminal of the fourth resistor R4 is connected to a fifth terminal of the differential amplifying unit 110.

Referring specifically to FIG. 2, Vref is the reference voltage, external power supplyThe voltage of VDD is divided by the fifth resistor R5 and the sixth resistor R6 to obtain a reference voltage Vref, and the reference voltage Vref is greater than the turn-on voltage of the second transistor E2. When the voltage Vin of the level signal is low, only the second transistor E2 operates normally, and the voltage V1 at the common source node is Vref-V_GS2，V_GS2The voltage between the gate and the source of the second transistor E2, at this time, the level shift module 200 and the switch module 300 are both in the off state according to the first off signal, and the low noise amplifier operates normally; referring to fig. 3, when the voltage Vin of the level signal is high and is greater than or equal to the reference voltage Vref, the first transistor E1 is turned on, and the current flowing through the bias resistor Rb increases, the voltage V1 at the common source node increases, and V is increased_GS2When the voltage at Vout is 0, that is, the low noise amplifier cannot operate normally, the circuit is turned off.

Optionally, the first voltage division unit 120 may include: a fifth resistor R5 and a sixth resistor R6; a first end of the fifth resistor R5 is connected to both the first end of the first voltage division unit 120 and the first end of the sixth resistor R6, and a second end of the fifth resistor R5 is connected to the second end of the first voltage division unit 120; a second terminal of the sixth resistor R6 is connected to the third terminal of the first voltage divider 120.

The differential comparison module 100 of this embodiment mainly compares the voltage of the level signal with a reference voltage, where the reference voltage is the voltage at the connection point of the fourth resistor R4 and the fifth resistor R5, that is, compares the voltage at the first end of the differential amplification unit 110 with the voltage at the fifth end, and further controls the operating state of the low noise amplifier. When the voltage Vin of the level signal is less than the reference voltage Vref, the first transistor E1 is turned off, the second transistor E2 is turned on, the differential comparison module 100 outputs a first off signal, the level shift module 200 and the switch module 300 are both turned off, and the connected external low noise amplifier normally operates; when the voltage Vin of the level signal is greater than or equal to the reference voltage Vref, the differential comparison module 100 outputs a first conducting signal, that is, the output signal is a high level, the level shift module 200 and the switch module 300 are both conducting, and at this time, the voltage at Vout is 0, the low noise amplifier cannot normally operate, and the circuit is turned off, so that the low noise amplifier can be applied in the time division duplex mode, the average delay time of state switching is short, the switching speed is high, the reference voltage is easy to adjust, and the applicability is strong.

In one embodiment, referring to fig. 2, the level shift module 200 may include: a third transistor E3, a second voltage division unit 210, and a seventh resistor R7; the gate of the third transistor E3 is connected to the input terminal of the level shift module 200, the drain of the third transistor E3 is connected to the voltage terminal of the level shift module 200, and the source of the third transistor E3 is connected to the input terminal of the second voltage divider 210 and the first terminal of the seventh resistor R7; the output end of the second voltage division unit 210 is connected with the output end of the level shift module 200; the second terminal of the seventh resistor R7 is connected to ground.

Optionally, the second voltage division unit 210 may include: a fourth transistor E4; the gate of the fourth transistor E4 is connected to the input terminal of the second voltage division unit 210, and the source and the drain of the fourth transistor E4 are both connected to the output terminal of the second voltage division unit 210.

Optionally, the second voltage division unit 210 may further include: a Schottky diode; the anode of the schottky diode is connected to the input terminal of the second voltage dividing unit 210, and the cathode of the schottky diode is connected to the output terminal of the second voltage dividing unit 210.

The level conversion module can convert an input signal into a bias signal inside the control circuit, so that the subsequent circuit is used, the independence of a key circuit power supply is ensured, and the output crosstalk or distortion of the circuit caused by power supply noise is avoided. Specifically, the level signal passes through the differential comparison module 100 and is input to the third transistor E3, the third transistor E3 performs level shifting on the first on signal, and when the voltage Vin of the level signal is greater than or equal to the turn-on voltage of the first transistor E1, the level of the first on signal can be shifted down by V_GS3，V_GS3Is a voltage between the gate and the source of the third transistor E3; then the voltage is divided by a Schottky diode or a fourth transistor E4 to obtain a fifth crystalThe transistor E5 supplies a gate voltage (second on signal). The third transistor E3 is used as a source output tube, so that the output phase and the logic relation are unchanged, the problem of mutual coupling of the front stage and the rear stage is solved, and the load capacity of the circuit is improved.

In one embodiment, the switch module 300 may include: a fifth transistor E5, a first capacitor C1, and an eighth resistor R8; a first end of the eighth resistor R8 is connected to the input end of the switch module 300, a second end of the eighth resistor R8 is connected to both the gate of the fifth transistor E5 and the first end of the first capacitor C1, a drain of the fifth transistor E5 is connected to the output end of the switch module 300, and a source of the fifth transistor E5 is grounded; the second terminal of the first capacitor C1 is connected to ground. The eighth resistor R8 can limit the gate current of the fifth transistor E5, and ensure that the gate of the fifth transistor E5 is not damaged due to excessive current; the first capacitor C1 combines with the eighth resistor R8 to form a low-pass filter circuit, when the input level signal fluctuates, the low-pass filter circuit can filter the input signal, and the anti-interference capability of the control circuit is improved.

Optionally, the switch module 300 may further include: a ninth resistor R9; a first terminal of the ninth resistor R9 is connected to the gate of the fifth transistor E5, and a second terminal of the ninth resistor R9 is grounded. When the control circuit has no signal input or the input terminal of the switch module 300 is low, the ninth resistor R9 pulls the gate of the fifth transistor E5 to ground.

The switch module 300 is connected to the bias circuit of the low noise amplifier, so that the on or off of the low noise amplifier is controlled by one transistor, and a pull-down resistor (a ninth resistor R9) is added in front of the fifth transistor E5, so that the input terminal of the switch module 300 can be stably in a low level state when no high level input is performed, and the malfunction that the inverter of the low noise amplifier is turned over towards the end outputting the low level due to the high level interference when the high level input is performed is prevented.

The fifth transistor E5 of the switching module 300 is an enhancement mode PHEMT device. The enhanced PHEMT device is a voltage control device in which the channel resistance is controlled by the gate voltage and the drain current is controlled by the channel resistance. When the voltage V between the gate and the source of the fifth transistor E5_GS5When the voltage is larger than the turn-on voltage of the fifth transistor E5, electrons flow into the quantum well to form a two-dimensional electron gas, and at the moment, a voltage is applied to the drain electrode, and the electrons in the channel form a drain current I under the action of an external electric field_DS5(ii) a And when the gate-source voltage of the fifth transistor E5 is continuously increased, the two-dimensional electron gas concentration in the channel is also increased, the channel resistance is reduced, and the drain current I is increased_DS5The output voltage Vout is set to 0, so that the low noise amplifier is turned off, and the low noise amplifier can still keep stable in a high-temperature and low-temperature state.

Optionally, the first transistor E1, the second transistor E2, the third transistor E3, the fourth transistor E4, and the fifth transistor E5 in this embodiment may all be enhancement mode PHEMTs of gallium arsenide material. The control circuit of the embodiment can be manufactured based on an enhanced PHEMT process of a gallium arsenide material, and can be compatible with a low-noise amplifier process.

In the above embodiment, the circuit mainly includes the differential comparison module 100, the level shift module 200 and the switch module 300, and has a simple structure, a small size, easy control and low power consumption; the differential comparison module 100 sends a first off signal to the level shift module 200 when the voltage of the level signal is less than the reference voltage, or sends a first on signal to the level shift module 200 when the voltage of the level signal is greater than or equal to the reference voltage; the level shift module 200 is turned off according to the first cut-off signal, or performs level shift on the first conducting signal, so as to avoid output crosstalk or distortion of the circuit caused by power noise, and have strong anti-interference capability; the switch module 300 turns off the external low noise amplifier according to the second off signal, or turns on the external low noise amplifier according to the second on signal to turn off the external low noise amplifier, so that the low noise amplifier is applied in the time division duplex mode, and has a large input impedance and a small output impedance, so that the circuit driving capability is strong, the switching speed is high, and the common mode interference resistance is strong, thereby meeting the requirements of the low noise amplifier in the fifth generation mobile communication base station.

The embodiment further provides a low noise amplifier, which can be applied to a fifth generation mobile communication base station, and includes a low noise amplifier chip, and further includes any one of the control circuits described in the above embodiments connected to the low noise amplifier chip, and has the beneficial effects of the control circuit.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.