CN111510089B - A low-noise amplifier module with bypass function and its control method - Google Patents

Abstract

The invention discloses a low-noise amplifying module with bypass function and a control method thereof, belonging to the technical field of monolithic radio frequency/microwave integrated circuits; the low-noise amplification module with the bypass function comprises a first single-pole double-throw radio frequency switch, a second single-pole double-throw radio frequency switch and a low-noise amplifier; the first output end of the first single-pole double-throw radio frequency switch is connected with the input end of the low-noise amplifier; the second output end of the first single-pole double-throw radio frequency switch is connected with the first input end of the second single-pole double-throw radio frequency switch; the output end of the low-noise amplifier is connected with the second input end of the second single-pole double-throw radio frequency switch; the invention integrates two radio frequency switches on the basis of the low noise amplifier, thereby realizing the bypass function. The method has obvious influence on the range of the input signal, can process the signal with the amplitude lower than that of the input 1dB compression point signal of the low noise amplifier, can process the signal with the amplitude higher than that of the input 1dB compression point signal, and effectively improves the dynamic range of the system.

Description

A low-noise amplifier module with bypass function and its control method

technical field

The invention discloses a low-noise amplification module with a bypass function and a control method, belonging to the technical field of single-chip radio frequency/microwave integrated circuits.

Background technique

Low-noise amplifiers are key components in wireless transceiver systems, and are widely used in wireless communications, radio and television, and point-to-point communications. The low noise amplifier is in the first stage of the receiver, and its noise figure plays a decisive role in the noise figure of the system. In the system, the traditional low noise amplifier is in the working state when receiving the signal, and is in the off state when transmitting the signal. When receiving a signal, limited by the signal processing capability of the low noise amplifier itself, the output signal cannot be too large, otherwise the low noise amplifier will be pushed to saturation, and the signal that is too large may burn the low noise amplifier.

In modern wireless transceiver systems, low-noise amplifiers need to be capable of large-signal transmission in addition to processing small-signal amplification; however, there is still a lack of related technologies.

Contents of the invention

Based on the problems existing in the prior art, the present invention implements a low-noise amplifier module with a bypass function and a control method based on the GaAs PHEMT process, the purpose of which is to improve the signal dynamic range of the low-noise amplifier.

In the first aspect of the present invention, the present invention provides a low-noise amplifier module with a bypass function, the low-noise amplifier module includes a first single-pole double-throw radio frequency switch, a second single-pole double-throw radio frequency switch and a low-noise amplifier ; The first output end of the first single-pole double-throw radio frequency switch is connected with the input end of the low-noise amplifier; the second output end of the first single-pole double-throw radio frequency switch is connected with the first input end of the second single-pole double-throw radio frequency switch; low noise The output terminal of the amplifier is connected with the second input terminal of the second SPDT radio frequency switch.

Preferably, the first single pole double throw radio frequency switch and the second single pole double throw radio frequency switch are the same switch.

Optionally, the switch includes a plurality of transistors for turning on and off, a plurality of capacitors for isolating the external DC voltage, and a plurality of resistors for serially inputting a control signal into the radio frequency terminal.

Preferably, the switch includes two transistors, three capacitors and three resistors; the source of the transistor M1 is connected to the capacitor C1; the drain of the transistor M1 is connected to the capacitor C3; the gate of the transistor M1 is connected to the resistor R1; the source of the transistor M2 The pole is connected to the capacitor R3; the drain of the transistor M2 is connected to the capacitor C2; the gate of the transistor M2 is connected to the resistor R2; wherein, both the resistor R1 and the resistor R3 are connected to the voltage VC; the resistor R2 is grounded.

Further, the low-noise amplifier includes a bias network, an amplification network, and a negative feedback network; the bias network provides a DC bias for the transistors of the amplification network; the amplification network is used to amplify radio frequency signals; the negative A feedback network is used to achieve impedance matching.

Preferably, the bias network includes a transistor M3, five resistors R4, R5, R6, R7, R8, two capacitors C3, C4, and an inductor L1; one end of the resistor R4 is connected to the power supply, and the other end is connected to the drain of the transistor M3 The drain of the transistor M3 is connected to the gate; one end of the capacitor C4 is connected to the ground, and the other end is connected to the gate of the transistor M3; one end of the resistor R5 is connected to the gate of the transistor M3, and the other end provides a bias for the amplifying network; one end of the resistor R6 Connect the power supply, the other end is connected to resistors R7 and R8; the other end of resistor R8 is connected to ground; the other end of resistor R7 provides DC bias for the transistor of the amplifying network; one end of capacitor C5 is connected to one end of R8, and the other end is grounded; one end of inductor L1 is connected to the power supply, One end powers the transistors of the amplifying network.

Preferably, the amplifying network includes two transistors, namely transistors M4 and M5, the source of the transistor M4 is connected to the ground, and the drain of the transistor M4 is connected to the source of the transistor M5.

Preferably, the negative feedback network includes a capacitor C6 and a resistor R9, wherein one end of the capacitor C6 is connected to the transistor drain of the amplifying network, and the other end is connected to the resistor R9; the other end of the resistor R9 is connected to the gate of the transistor of the amplifying network.

In the second aspect of the present invention, the present invention also provides a low noise amplification control method with a bypass function; the method includes:

Input RF signal from IN port;

Selecting a channel through the first single-pole double-throw radio frequency switch, and selecting the first channel or the second channel;

In the first path, select to enter the low-noise amplifier to realize signal amplification, and transmit to the OUT port after passing through the second single-pole double-throw radio frequency switch;

In the second path, the selection is transmitted to the OUT port after passing through the second SPDT RF switch.

Preferably, in order to improve the overall dynamic range of the system, the first path or the second path is selected through the 1dB compression point. When the RF signal input from the IN port is lower than the low noise amplifier input 1dB compression point, the first path is selected for signal amplification. Send it to the post-processing; when the RF signal input from the IN port is greater than the 1dB compression point of the low-noise amplifier input, because the low-noise amplifier cannot handle such signals, the second channel is selected to transmit the signal to the post-processing.

Beneficial effects of the present invention: the patent of the present invention integrates two radio frequency switches on the basis of the low noise amplifier, so as to realize the bypass function. The input signal range has a significant impact, and the present invention can process signals whose amplitude is lower than the input 1dB compression point of the low noise amplifier, and can also process signals whose amplitude is greater than the input 1dB compression point, effectively improving the dynamic range of the system.

Description of drawings

Fig. 1 is a structure diagram of a traditional low noise amplifier;

Fig. 2 is the overall block diagram of the low noise amplification module with bypass function of the present invention;

Fig. 3 is the radio frequency switch circuit diagram in the low noise amplifying module with bypass function of the present invention;

Fig. 4 is the overall block diagram of the low noise amplifier in the low noise amplifier module with bypass function of the present invention;

Fig. 5 is the circuit diagram of the low noise amplifier module with bypass function of the present invention;

Fig. 6 is a flow chart of the low noise amplification control method with bypass function of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1, it is a block diagram of a traditional low-noise amplifier, including an input port (IN port) and an output port (OUT port). When the signal exceeds the input 1dB compression point of the LNA, the LNA output signal is compressed and distorted.

In one embodiment, in order to solve the defects of the traditional low noise amplifier; the present invention adopts the overall block diagram of the low noise amplifier module with bypass function as shown in FIG. 2 .

The low-noise amplifier module with bypass function includes a first single-pole double-throw radio frequency switch K1, a second single-pole double-throw radio frequency switch K2 and a low-noise amplifier AMP; the first output end RF1 of the first single-pole double-throw radio frequency switch is connected to the low The noise amplifier input terminal LNA-IN is connected; the second output terminal RF2 of the first single-pole double-throw radio frequency switch is connected with the first input terminal RF1 of the second single-pole double-throw radio frequency switch; the low-noise amplifier output terminal LNA-OUT is connected with the second single-pole double-throw radio frequency switch The second input terminal R2 of the double-throw radio frequency switch is connected.

The first single pole double throw radio frequency switch K1 and the second single pole double throw radio frequency switch K2 can realize the signal path selection function; the low noise amplifier AMP realizes the signal amplification function. The input signal can be amplified or passed through through RF switches K1 and K2.

Since the RF switch and the low-noise amplifier are integrated at the same time, when the signal amplitude is lower than the input 1dB compression point of the low-noise amplifier, the RF signal is transmitted to the amplifier AMP through the RF switch K1, and then transmitted to the RF switch K2 after being amplified by the amplifier AMP; When the signal amplitude is greater than the input 1dB compression point of the low-noise amplifier, the signal is directly transmitted to the RF switch K2 through the RF switch K1, and then transmitted to the subsequent stage through K2. Since the 1dB compression point of the RF switch itself is high, the signal will not be compressed.

In one embodiment, the first single-pole double-throw radio frequency switch and the second single-pole double-throw radio frequency switch are the same switch; the switch includes a plurality of transistors for turning on and off, and is used for isolating external DC Multiple capacitors for the voltage and multiple resistors for the control signal to be serially connected to the radio frequency terminal; through this embodiment, the number of control signals can be reduced without designing a numerical control circuit, and the design complexity can be greatly simplified.

The input signal can be amplified or passed through through RF switches K1 and K2. When the signal is lower than the input 1dB compression point of the low noise amplifier, the input signal is selected to enter the input terminal of the low noise amplifier through the switch K1 to realize signal amplification, and the amplified signal is output through the switch K2; when the signal is higher than the input 1dB compression point of the low noise amplifier , the input signal selects the through path through the switch K1 and directly enters the switch K2, which can avoid the signal from being compressed and distorted.

In a preferred embodiment, as shown in FIG. 3, the switch may further include two transistors, three capacitors and three resistors; the source of transistor M1 is connected to capacitor C1; the drain of transistor M1 is connected to capacitor C3; The gate of M1 is connected to resistor R1; the source of transistor M2 is connected to capacitor R3; the drain of transistor M2 is connected to capacitor C2; the gate of transistor M2 is connected to resistor R2; where both resistors R1 and resistor R3 are connected to voltage VC; resistor R2 is grounded ; In this embodiment, the transistors M1 and M2 are turned on or off by controlling the voltage VC. Transistor M1 is turned on and off by controlling the gate, and the gate of transistor M2 is clamped to ground, and can be turned on and off by controlling its source, which is very low in complexity and easy to implement.

In this embodiment, the control voltage VC provides control signals for the transistors M1 and M2 through the resistors R3 and R1. The control voltage VC controls the gate voltage of the transistor M1 to turn the transistor M1 on or off; in addition, controls the source of the transistor M2 through the resistor R3 to turn the transistor M2 on or off. The advantage of this control method is that one control signal can be used to realize the function of one transistor being turned on and one transistor being turned off.

In one embodiment, as shown in Figure 4, a block diagram structure of a low-noise amplifier is provided, and the low-noise amplifier includes a bias network, an amplification network and a negative feedback network; The transistor provides DC bias; the amplifying network is used to realize the radio frequency signal amplification function; the negative feedback network is used to realize impedance matching; the bias network provided by the present invention can adopt a CASCODE (common gate) amplifying structure to provide a low noise amplifier. grid voltage bias; the negative feedback network can achieve good input and output return loss in a wider frequency band; the amplification network can achieve high power gain; the low noise amplifier realized by this embodiment has low power supply current and The radio frequency parameters are more stable.

In a preferred embodiment, as shown in Figure 5, the circuit structure of each network in a kind of low noise amplifier is provided:

The bias network includes a transistor M3, five resistors R4, R5, R6, R7, R8, two capacitors C3, C4, and an inductor L1; one end of the resistor R4 is connected to the power supply, and the other end is connected to the drain of the transistor M3; The drain of M3 is connected to the gate; one end of the capacitor C4 is connected to the ground, and the other end is connected to the gate of the transistor M3; one end of the resistor R5 is connected to the gate of the transistor M3, and the other end provides a bias for the amplification network; one end of the resistor R6 is connected to the power supply, The other end is connected to resistors R7 and R8; the other end of resistor R8 is connected to ground; the other end of resistor R7 provides DC bias for the transistor M5 of the amplifying network; one end of capacitor C5 is connected to one end of R8, and the other end is grounded; one end of inductor L1 is connected to the power supply, and the other end is connected to The drain of transistor M5 supplies power to transistor M5 of the amplification network.

The amplifying network includes two transistors, i.e. transistors M4 and M5, the source of the transistor M4 is connected to the ground, the drain of the transistor M4 is connected to the source of the transistor M5; the drain of the transistor M5 is connected to the inductance L1 of the bias network, M4 The source is connected to resistor R5 of the bias network.

The negative feedback network includes a capacitor C6 and a resistor R9, wherein one end of the capacitor C6 is connected to the drain of the transistor M5 of the amplifying network, and the other end is connected to the resistor R9; the other end of the resistor R9 is connected to the gate of the transistor M4 of the amplifying network.

Through the above settings, the power supply current and radio frequency parameters of the low noise amplifier can be made more stable at high and low temperatures.

In the field of low-noise amplifiers, the enhanced PHEMT of gallium arsenide material has great advantages. At present, domestic and foreign manufacturers mainly focus on the enhanced PHEMT process for high-performance low-noise amplifier products, and the working frequency band of the fifth-generation mobile communication system One is the sub 6G frequency band. In this frequency band, the enhanced PHEMT process of gallium arsenide material has a low noise figure, can provide high gain, has high linearity and transconductance, and only needs a single power supply to meet design requirements for low noise amplifiers.

In one embodiment, optionally, the transistor in the present invention is an enhancement mode PHEMT device. The enhanced PHEMT device is a voltage-controlled device that controls the channel resistance by the gate voltage and controls the drain current through the channel resistance. All the transistors M1 , M2 , M3 , M4 and M5 in this embodiment can be enhancement-mode PHEMTs made of GaAs material. The radio frequency switch of this embodiment can be manufactured based on the enhanced PHEMT process of gallium arsenide material, and can be compatible with the low noise amplifier process.

In one embodiment, as shown in FIG. 6, the present invention also provides a low noise amplification control method with a bypass function, the method comprising:

Input RF signal from IN port;

Selecting a channel through the first single-pole double-throw radio frequency switch, and selecting the first channel or the second channel;

In the first path, select to enter the low-noise amplifier to realize signal amplification, and transmit to the OUT port after passing through the second single-pole double-throw radio frequency switch;

In the second path, the selection is transmitted to the OUT port after passing through the second SPDT RF switch.

In a preferred embodiment, when the RF signal input from the IN port is lower than the low-noise amplifier input 1dB compression point, the first path is selected to amplify the signal and sent to the post-stage processing; when the RF signal input from the IN port is greater than the low When the noise amplifier enters the 1dB compression point, select the second channel to transmit the signal to the post-processing.

In a supplementary embodiment, this embodiment also provides a low-noise amplifier chip, which can be applied to the fifth-generation mobile communication base station, including any low-noise amplifier module with bypass function described in the above-mentioned embodiments , and has the beneficial effects of the above-mentioned control circuit.

It can be understood that some features of the amplification module and the control method in the present invention may be referred to each other, and the present invention will not give examples one by one.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (8)

1. A low-noise amplification module with bypass function, characterized in that, comprises the first single-pole double-throw radio frequency switch, the second single-pole double-throw radio frequency switch and low-noise amplifier; the first output of the first single-pole double-throw radio frequency switch end is connected with the input end of the low noise amplifier; the second output end of the first single pole double throw radio frequency switch is connected with the first input end of the second single pole double throw radio frequency switch; the output end of the low noise amplifier is connected with the second single pole double throw radio frequency switch The second input terminal is connected; the low noise amplifier includes a bias network, an amplification network and a negative feedback network; the bias network provides a DC bias for the transistor of the amplification network; the amplification network is used to realize the radio frequency signal amplification function; The negative feedback network is used to achieve impedance matching; the bias network includes a transistor M3, five resistors R4, R5, R6, R7, R8, two capacitors C4, C5, and an inductor L1; one end of the resistor R4 is connected to the power supply , the other end is connected to the drain of the transistor M3; the drain of the transistor M3 is connected to the gate; one end of the capacitor C4 is connected to the ground, and the other end is connected to the gate of the transistor M3; one end of the resistor R5 is connected to the gate of the transistor M3, and the other end is an amplifier The network provides bias; one end of resistor R6 is connected to the power supply, the other end is connected to resistors R7 and R8; the other end of resistor R8 is connected to ground; the other end of resistor R7 provides DC bias for the transistor of the amplifying network; one end of capacitor C5 is connected to one end of R8, and the other end is grounded ; One end of the inductor L1 is connected to the power supply, and the other end supplies power to the transistor of the amplifying network. 2. A low-noise amplifier module with a bypass function according to claim 1, wherein the first single-pole double-throw radio frequency switch and the second single-pole double-throw radio frequency switch are the same switch. 3. A low-noise amplification module with a bypass function according to claim 2, wherein each single-pole double-throw radio frequency switch includes a plurality of transistors for turning on and off, for isolating external Multiple capacitors for the DC voltage and multiple resistors for the control signal to be connected to the RF terminal. 4. A kind of low-noise amplifier module with bypass function according to claim 2, is characterized in that, each SPDT radio frequency switch also comprises two transistors, three electric capacity and three resistances; The source of transistor M1 The pole connection capacitor C1; the drain connection capacitance C3 of the transistor M1; the gate connection resistance R1 of the transistor M1; the source connection resistance R3 of the transistor M2; the drain connection capacitance C2 of the transistor M2; the gate connection resistance R2 of the transistor M2; Wherein, both the resistor R1 and the resistor R3 are connected to the voltage VC; the resistor R2 is grounded. 5. A low-noise amplifying module with a bypass function according to claim 1, wherein the amplifying network includes two transistors, i.e. transistors M4 and M5, the source of transistor M4 is connected to ground, and the source of transistor M4 is connected to the ground. The drain of is connected to the source of transistor M5. 6. A low-noise amplifying module with a bypass function according to claim 1, wherein the negative feedback network includes a capacitor C6 and a resistor R9, wherein one end of the capacitor C6 is connected to the transistor drain of the amplifying network, and the other is One end is connected to the resistor R9; the other end of the resistor R9 is connected to the transistor gate of the amplifying network. 7. A low-noise amplification control method with a bypass function, which is applied to a low-noise amplification module with a bypass function as claimed in any one of claims 1 to 6, wherein the method comprises: Input RF signal from IN port; Selecting a channel through the first single-pole double-throw radio frequency switch, and selecting the first channel or the second channel; In the first path, select to enter the low-noise amplifier to realize signal amplification, and transmit to the OUT port after passing through the second single-pole double-throw radio frequency switch; In the second path, the selection is transmitted to the OUT port after passing through the second SPDT radio frequency switch, and the amplified radio frequency signal is output from the OUT port. 8. A kind of low-noise amplification control method with bypass function according to claim 7, it is characterized in that, when the radio frequency signal input from the IN port is lower than the low-noise amplifier input 1dB compression point, select the first path to carry out After the signal is amplified, it is sent to the post-stage processing; when the RF signal input from the IN port is greater than the 1dB compression point of the low-noise amplifier input, the second channel is selected to transmit the signal to the post-stage processing.