CN115061524B - Power control circuit of multimode radio and multimode radio - Google Patents

Abstract

The present application discloses a power control circuit of a multi-mode radio station and a multi-mode radio station, and relates to the field of power control technology. The power control circuit of the multi-mode radio station includes a power amplifier, a directional coupler, and a control loop; the output end of the radio frequency excitation signal is connected to the input end of the power amplifier; the output end of the power amplifier is connected to the input end of the directional coupler; the output end of the directional coupler is connected to the antenna, and the coupling end of the directional coupler is connected to the input end of the control loop; the output end of the control loop is connected to the input end of the power amplifier; wherein the control loop includes a constant envelope control loop and a non-constant envelope control loop, the constant envelope control loop is used to perform power control on the constant envelope signal; the non-constant envelope control loop is used to perform power control on the non-constant envelope signal. Through the above-mentioned method, the present application can meet the power control of constant envelope and non-constant envelope signals, make the designed algorithm simple, and reduce the difficulty of power control of the multi-mode radio station.

Description

Power control circuit of multi-mode radio station and multi-mode radio station

Technical Field

The present application relates to the technical field of power control, and in particular to a power control circuit of a multi-mode radio station and a multi-mode radio station.

Background Art

With the development of radio stations, factors such as broadband, multi-mode, multi-test, and multi-waveform of radio stations have increased the complexity of radio power control. The current radio power control has current feedback power control and voltage feedback power control. The voltage feedback power control method uses a directional coupler between the power amplifier and the antenna port to couple the power, and then detects it through a detector. The error voltage is obtained by comparing the voltage signal with the reference voltage, thereby controlling the gain of the power amplifier to ensure that the power output of the power amplifier is stable, and at the same time, it is necessary to ensure that the signal transmission is not distorted. However, the current multi-mode radio station has constant envelope and non-constant envelope modulation signals, and the frequency hopping rate is hundreds to tens of thousands of hops per second. The above factors make power control more difficult.

Summary of the invention

The present application proposes a power control circuit of a multi-mode radio station and a multi-mode radio station, so as to solve the problem that the power control of the multi-mode radio station is too difficult.

In order to solve the above technical problems, a technical solution adopted in the present application is: providing a power control circuit of a multi-mode radio station, the power control circuit of the multi-mode radio station includes a power amplifier, a directional coupler, and a control loop; the power control circuit performs power control on the radio frequency excitation signal of the multi-mode radio station, and transmits the radio frequency excitation signal after power control through an antenna; wherein the output end of the radio frequency excitation signal is connected to the input end of the power amplifier; the output end of the power amplifier is connected to the input end of the directional coupler; the output end of the directional coupler is connected to the antenna, and the coupling end of the directional coupler is connected to the input end of the control loop; the output end of the control loop is connected to the input end of the power amplifier; wherein the control loop includes a constant envelope control loop and a non-constant envelope control loop, the constant envelope control loop is used to perform power control on the constant envelope signal; the non-constant envelope control loop is used to perform power control on the non-constant envelope signal.

The control loop further includes a switch, the input end of the switch inputs a reference voltage; the first output end of the switch is connected to the input end of the constant envelope control loop; the second output end of the switch is connected to the input end of the non-constant envelope control loop.

Among them, the non-constant envelope control loop includes a peak detector and a first operational amplifier comparator, the input end of the peak detector is connected to the coupling end of the directional coupler; the first input end of the first operational amplifier comparator is connected to the output end of the peak detector, the second input end of the first operational amplifier comparator inputs the non-constant envelope signal, and the second input end of the first operational amplifier comparator is connected to the second output end of the switch, and the output end of the first operational amplifier comparator is connected to the input end of the power amplifier.

The non-constant envelope control loop further includes a first capacitor, a first end of the first capacitor is connected to a first input end of the first operational amplifier comparator, and a second end of the first capacitor is connected to an output end of the first operational amplifier comparator.

The non-constant envelope control loop further comprises an adjustable attenuator, the input end of the adjustable attenuator is connected to the coupling end of the directional coupler, and the output end of the adjustable attenuator is connected to the input end of the peak detector.

Wherein, the peak detector includes a second capacitor, a first resistor, a first diode, a second diode, a second resistor and a third capacitor, wherein the first end of the second capacitor is connected to the output end of the adjustable attenuator; the first end of the first resistor is connected to the second end of the second capacitor; the forward end of the first diode is connected to the second end of the first resistor and is grounded; the negative end of the first diode is connected to the second end of the second capacitor; the forward end of the second diode is respectively connected to the second end of the second capacitor and the negative end of the first diode; the first end of the second resistor is connected to the negative end of the second diode; the second resistor is connected to the first input end of the first operational amplifier comparator; the first end of the third capacitor is grounded, and the second end of the third capacitor is connected to the second end of the second resistor.

The first diode and the second diode include Schottky diodes.

Among them, the constant envelope control loop includes a mean detector and a second operational amplifier comparator, the input end of the mean detector is connected to the coupling end of the directional coupler; the first input end of the second operational amplifier comparator is connected to the output end of the mean detector, the second input end of the second operational amplifier comparator is connected to the first output end of the switch, and the output end of the second operational amplifier comparator is connected to the input end of the power amplifier.

Among them, the constant envelope control loop further includes a fourth capacitor and a third resistor, the first end of the fourth capacitor is connected to the first input end of the second operational amplifier comparator; the first end of the third resistor is connected to the second end of the fourth capacitor, and the third resistor is connected to the output end of the second operational amplifier comparator.

In order to solve the above technical problems, another technical solution adopted in the present application is: to provide a multi-mode radio station, which includes the power control circuit of any of the above multi-mode radio stations.

The beneficial effect of the present application is that, different from the prior art, the control loop of the power control circuit of the multi-mode radio station of the present application sets a constant envelope control loop and a non-constant envelope control loop, and performs power control on the constant envelope signal and the non-constant envelope signal of the multi-mode radio station respectively, so that the power control circuit of the multi-mode radio station of the present application can meet the power control of the constant envelope and non-constant envelope signals, and compared with the prior art, the use of a dual control loop in the power control circuit of the multi-mode radio station of the present application can greatly reduce the difficulty of the design algorithm of the multi-mode radio station power control, thereby reducing the cost of the multi-mode radio station power control.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a conventional power control of a multi-mode radio station;

FIG2 is a schematic diagram of the structure of a conventional single-loop power control;

FIG3 is a schematic structural diagram of a first embodiment of a power control circuit of a multi-mode radio station of the present application;

FIG4 is a schematic diagram of the structure of a second embodiment of a power control circuit of a multi-mode radio station of the present application;

FIG5 is a partial structural diagram of an embodiment of a non-constant envelope control loop of the present application;

FIG6 is a schematic diagram of an actual control circuit of an embodiment of a control loop of the present application;

7 is a waveform diagram of an embodiment of power control and modulation of a predistortion of a radio frequency excitation signal of the present application;

FIG8 is a schematic diagram of the structure of a multi-mode radio station according to an embodiment of the present application.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

In order to solve the power control problem of multi-mode radio stations, the current existing technology for controlling the power of multi-mode radio stations is a software power control method. Please refer to Figure 1. Figure 1 is a structural diagram of traditional power control of multi-mode radio stations. As shown in Figure 1, the input signal RF_IN is input to the input end of the power amplifier 1, and the output signal of the power amplifier 1 obtains a forward coupled signal through a directional coupler 2. The forward coupled signal then enters the detector 3 for detection, and the obtained voltage signal is converted into a digital signal through an analog-to-digital converter 4 (Analog-to-digital Converter, ADC), enters a field programmable gate array 5 (Field Programmable Gate Array, FPGA) to be compared with a factory-calibrated reference signal, and the obtained control digital signal then enters a digital-to-analog converter 6 (Digital to Analog Convertor, DAC), and controls the gain of the power amplifier 1 through an operational amplifier circuit 7, thereby achieving closed-loop control of the power of the multi-mode radio station.

However, in the software power control method in the prior art, the signal needs to fit more frequency points and power registrations, and a higher sampling rate is required for non-constant envelope signals to meet the accuracy of signal detection, which leads to a more complex design algorithm for the software power control method, more difficult production and higher production cost.

Next, please refer to FIG. 2, which is a schematic diagram of the structure of the traditional single-loop power control. As shown in FIG. 2, the output end of the RF excitation signal is connected to the input end of the power amplifier 10; the output end of the power amplifier 10 is connected to the input end of the directional coupler 20; the output end of the directional coupler 20 is connected to the antenna 40, and the coupling end of the directional coupler 20 is connected to the input end of the mean detector 311, the output end of the mean detector 311 is connected to the first input end of the third operational amplifier comparator 70, the second input end of the third operational amplifier comparator 70 inputs the reference voltage APC, and the output end of the third operational amplifier comparator 70 is connected to the power amplifier. A resistor and a capacitor are connected between the first input end and the output end of the third operational amplifier comparator 70.

As the power control complexity of multi-mode radio increases due to factors such as wideband, multi-mode, multi-test, and multi-waveform, the distortion of the excitation RF signal of the traditional single-loop power control of multi-mode radio gradually increases, and the transmission efficiency gradually decreases.

In order to solve the problem of power control of multi-mode radio in the prior art, the present application first proposes a power control circuit of a multi-mode radio. Please refer to FIG3 , which is a schematic diagram of the structure of the first embodiment of the power control circuit of the multi-mode radio of the present application. As shown in FIG3 , the power control circuit 100 of the multi-mode radio of the present embodiment includes a power amplifier 10, a directional coupler 20, and a control loop 30; the power control circuit 100 performs power control on the RF excitation signal of the multi-mode radio, and transmits the RF excitation signal after power control through the antenna 40; wherein, the output of the RF excitation signal The end is connected to the input end of the power amplifier 10; the output end of the power amplifier 10 is connected to the input end of the directional coupler 20; the output end of the directional coupler 20 is connected to the antenna 40, and the coupling end of the directional coupler 20 is connected to the input end of the control loop 30; the output end of the control loop 30 is connected to the input end of the power amplifier 10; wherein the control loop 30 includes a constant envelope control loop 31 and a non-constant envelope control loop 32, the constant envelope control loop 31 is used to perform power control on the constant envelope signal; the non-constant envelope control loop 32 is used to perform power control on the non-constant envelope signal.

The power amplifier 10 is used to amplify the RF excitation signal input by the multi-mode radio station; the directional coupler 20 is a passive four-port device with port reciprocity, one of which is isolated from the input port. Under ideal conditions, the four ports are fully matched and the circuit is lossless. The directional coupler 20 has four ports, an input port, an output port, a coupling port, and an isolation port. On some commercial couplers, the isolation port is usually terminated internally or externally with a matching load, making the four-port device look like a three-port device. The directional coupler 20 can be implemented in a variety of ways, such as microstrip lines, strip lines, coaxial lines, and waveguides, which are used to sample input and output signals. In this embodiment, the directional coupler 20 is used to detect the power of the RF excitation signal, obtain a positive coupling voltage signal, and input it into the control loop 30.

The control loop 30 includes a constant envelope control loop 31 and a non-constant envelope control loop 32. When the input RF excitation signal type is a constant envelope signal, the power control circuit 100 of the multi-mode radio station of this embodiment adopts the constant envelope control loop to control the power of the RF excitation signal. When the input RF excitation signal type is a non-constant envelope signal, the non-constant envelope control loop is used to control the power of the RF excitation signal.

Different from the prior art, the control loop 30 of the power control circuit 100 of the multi-mode radio station of the present application is provided with a constant envelope control loop 31 and a non-constant envelope control loop 32, which respectively perform power control on the constant envelope signal and the non-constant envelope signal of the multi-mode radio station, so that the power control circuit 100 of the multi-mode radio station of the present application can meet the power control of the constant envelope and non-constant envelope signals. Moreover, compared with the prior art, the use of a dual control loop in the power control circuit 100 of the multi-mode radio station of the present application can greatly reduce the difficulty of the design algorithm of the multi-mode radio station power control, thereby reducing the cost of the multi-mode radio station power control.

Optionally, please refer to FIG4 , which is a schematic diagram of the structure of the second embodiment of the power control circuit of the multi-mode radio station of the present application. As shown in FIG4 , the power control circuit 100 of the multi-mode radio station of the present embodiment further includes a switch 33, the input end of the switch 33 inputs the reference voltage APC; the first output end of the switch 33 is connected to the input end of the constant envelope control loop 31; the second output end of the switch 33 is connected to the input end of the non-constant envelope control loop 32.

The first output end of the switch 33 is connected to the input end of the constant envelope control loop 31 through the fourth resistor 331, one end of the fourth resistor 331 is connected to the first output end of the switch 33, and the other end of the fourth resistor 331 is connected to the input end of the constant envelope control loop 31; the second output end of the switch 33 is connected to the input end of the non-constant envelope control loop 32 through the fifth resistor 332, one end of the fifth resistor 332 is connected to the second output end of the switch 33, and the other end of the fifth resistor 332 is connected to the input end of the non-constant envelope control loop 32, and the fourth resistor 331 and the fifth resistor 332 are used to protect the switch 33.

The switch 33 can be connected to the constant envelope control loop 31 and the non-constant envelope control loop 32 according to the mode of the multi-mode radio. When the multi-mode radio is in the constant envelope mode, the input end of the switch 33 is connected to the first output end of the switch 33; when the multi-mode radio is in the non-constant envelope mode, the output end of the switch 33 is connected to the second output end of the switch 33. The switch 33 can be a chip ADG884. In other embodiments, the switch 33 can also be other circuit structures, as long as it meets the above functions, which is not limited here.

Different from the prior art, the setting of the switch 33 enables the power control circuit 100 of the multi-mode radio station to meet the power control of both constant envelope and non-constant envelope signals. The power control circuit 100 of the multi-mode radio station of the present application can select to connect the constant envelope control loop 31 and the non-constant envelope control loop 32 according to the constant envelope mode of the multi-mode radio station, thereby greatly reducing the difficulty of the power control design algorithm.

Optionally, please refer to Figure 4, the non-constant envelope control loop 32 includes a peak detector 321 and a first operational amplifier comparator 322, the input end of the peak detector 321 is connected to the coupling end of the directional coupler 20; the first input end of the first operational amplifier comparator 322 is connected to the output end of the peak detector 321, the second input end of the first operational amplifier comparator 322 inputs the non-constant envelope signal AM_audio, and the second input end of the first operational amplifier comparator 322 is connected to the second output end of the switch 33, and the output end of the first operational amplifier comparator 322 is connected to the input end of the power amplifier.

The second input terminal of the first operational amplifier comparator 322 receives the non-constant envelope signal AM_audio, and a sixth resistor 324 is set. One end of the sixth resistor is connected to the second input terminal of the first operational amplifier comparator 322, and the other end of the sixth resistor 324 receives the non-constant envelope signal AM_audio.

When the mode of the multi-mode radio is the non-constant envelope mode, the input end of the switch 33 is connected to the second output end of the switch 33. At this time, the power control circuit 100 of the multi-mode radio performs power control for the non-constant envelope signal. For the non-constant envelope signal AM_audio, the non-constant envelope signal AM_audio and the reference voltage APC are input to the second input end of the first operational amplifier comparator 322. The first input end of the first operational amplifier comparator 322 receives the voltage signal of the peak detector 321. The first operational amplifier comparator 322 integrates and compares the signals of the first input end and the second input end, and the obtained error signal is used to control the power amplifier 10, thereby realizing the power closed-loop control for the non-constant envelope signal. In this embodiment, the first input end of the first operational amplifier comparator 322 is a positive input end, and the second input end is a negative input end. In other embodiments, the first input end of the first operational amplifier comparator 322 can also be a negative input end, and the second input end can also be a positive input end, which is not limited here. In this embodiment, the peak detector 321 may be a MA4E2200 chip. In other embodiments, the peak detector 321 may also be other chips as long as it meets the function of the peak detector 321 in this embodiment, and is not limited here.

Optionally, the non-constant envelope control loop 32 further includes a first capacitor 323, a first end of the first capacitor 323 is connected to a first input end of the first operational amplifier comparator 322, and a second end of the first capacitor 323 is connected to an output end of the first operational amplifier comparator 322. The first capacitor 323 is provided to maintain the stability of the circuit.

Optionally, please refer to Figures 4 and 5, Figure 5 is a partial structural diagram of an embodiment of a non-constant envelope control loop of the present application, the non-constant envelope control loop 32 further includes an adjustable attenuator 325, the input end of the adjustable attenuator 325 is connected to the coupling end of the directional coupler 20, and the output end of the adjustable attenuator 325 is connected to the input end of the peak detector 321.

In this embodiment, an adjustable attenuator 325 is provided between the directional coupler 20 and the peak detector 321 to improve the detection dynamic range of the peak detector 321 .

Optionally, as shown in Figure 4, the peak detector 321 includes a second capacitor 3211, a first resistor 3212, a first diode 3213, a second diode 3214, a second resistor 3215 and a third capacitor 3216, the first end of the second capacitor 3211 is connected to the output end of the adjustable attenuator 325; the first end of the first resistor 3212 is connected to the second end of the second capacitor 3211; the positive end of the first diode 3213 is connected to the second end of the first resistor and grounded; the negative end of the first diode 3213 is connected to the second end of the second capacitor 3211; the positive end of the second diode 3214 is respectively connected to the second end of the second capacitor 3211 and the negative end of the first diode; the first end of the second resistor 3215 is connected to the negative end of the second diode 3214; the second resistor 3215 is connected to the first input end of the first operational amplifier comparator 322; the first end of the third capacitor 3216 is grounded, and the second end of the third capacitor 3216 is connected to the second end of the second resistor 3215.

Specifically, the first diode 3213 and the second diode 3214 include Schottky diodes. In this embodiment, the first diode 3213 and the second diode 3214 are silicon zero-bias p-type Schottky diodes.

With the increase of the modulation index of the RF excitation signal, the requirements for the threshold voltage of the detector are also increasing. Therefore, in order to detect the non-constant envelope type RF excitation signal, the present application sets up the above-mentioned new peak detector 321. Since the Schottky diode has the advantages of high switching frequency and low forward voltage drop, the forward conduction voltage of the first diode 3213 and the second diode 3214 of the peak detector 321 is extremely low, which can meet the detection requirements of input amplitude of -3 to +10dBm, modulation index greater than 95% and distortion less than 0.5%.

Optionally, please refer to Figure 4. As shown in Figure 4, the constant envelope control loop 31 includes a mean detector 311 and a second operational amplifier comparator 312. The input end of the mean detector 311 is connected to the coupling end of the directional coupler 20; the first input end of the second operational amplifier comparator 312 is connected to the output end of the mean detector 311, the second input end of the second operational amplifier comparator 312 is connected to the first output end of the switch 33, and the output end of the second operational amplifier comparator 312 is connected to the input end of the power amplifier 10.

When the mode of the multi-mode radio is the constant envelope mode, the input end of the switch 33 is connected to the first output end of the switch 33. At this time, the power control circuit 100 of the multi-mode radio performs power control for the constant envelope signal. The positive coupling voltage signal obtained by the directional coupler 20 is input into the mean detector 311. The mean detector 311 is connected to the first input end of the second op amp comparator 312. The reference voltage APC is input to the second input end of the second op amp comparator 312 through the first output end of the switch. The second op amp comparator 312 integrates and compares the signals at the first input end and the second input end, and the error signal obtained is used to control the power amplifier 10, thereby realizing the power closed-loop control for the constant envelope signal. In this embodiment, the mean detector 311 can use the LT5581 chip. In other embodiments, the mean detector 311 can also be other chips, as long as the function of the mean detector 311 in this embodiment is met, and it is not limited here.

Optionally, referring to FIG. 3 , the constant envelope control loop 31 of the present embodiment further includes a fourth capacitor 313 and a third resistor 314, wherein a first end of the fourth capacitor 313 is connected to a first input end of the second operational amplifier comparator 312; a first end of the third resistor 314 is connected to a second end of the fourth capacitor 313, and the third resistor 314 is connected to an output end of the second operational amplifier comparator 312.

The fourth capacitor and the third resistor 314 are also provided to maintain the stability of the circuit.

The power control circuit 100 of the multi-mode radio station of the present application adopts a dual-loop point power control method. For the constant envelope signal, the present application adopts a mean detector 311 for detection, and quickly integrates and compares the reference voltage APC with the voltage signal after mean detection, and uses the difference between the two to control the power amplifier 10, thereby realizing closed-loop power control; for the non-constant envelope signal, a new peak detector 321 is used for detection, and when performing closed-loop power control, the envelope following pre-distortion of the non-constant envelope signal can be satisfied, and the efficiency and distortion of the non-constant envelope signal can be effectively improved under the same saturation power. In addition, when the peak detector 321 of the present application adopts high linearity, it can also meet the frequency hopping power control of the non-constant envelope signal.

In an application scenario, please refer to FIG. 6 , which is a schematic diagram of an actual control circuit of an embodiment of a control loop of the present application.

As shown in Figure 6, the input end of the control loop is connected to the peak detector and the mean detector respectively, the peak detector is connected to the non-constant envelope loop control, the mean detector is connected to the constant envelope control loop, and the switch is connected to the non-constant envelope loop control and the constant envelope loop control, which is used for mode switching non-constant envelope loop control and constant envelope loop control based on a multi-mode radio station.

The peak detector uses a MA4E2200 silicon zero-bias p-type Schottky diode and RC to form a detector. The attenuator IDTF2255 chip is used to expand the detection dynamic range of the peak detector. The input end of the control loop is connected to the capacitor C14, the resistor R12, the resistor R10 and the capacitor C4 in sequence and connected to the RF2 end of the IDTF2255 chip. The GND1, GND2, GND3, GND4, NC1, NC2, NC3, NC4 and NC5 ends of the MA4E2200 chip are connected to the ground. The RTN1 end of the IDTF2255 chip is connected to the capacitor C9 and then to the ground. The RTN2 end of the MA4E2200 chip is connected to the capacitor C10 and then to the ground. The RTN3 end of the IDTF2255 chip is connected to the capacitor C11 and then to the ground. The VMODE end and the VDD end of the IDTF2255 chip are connected to a power supply with a voltage of 3V and a current of 3A, and are grounded through the capacitor C2. The VCTRL end of the IDTF2255 chip is connected to the adjustable attenuator 325.

The RF1 end of the IDTF2255 chip is connected to one end of the capacitor C3, the other end of the capacitor C3 is connected to the resistor R8 and grounded, and the other end of the capacitor C3 is connected to the 3 end of the MA4E2200 silicon zero bias p-type Schottky diode D1, the 1 end of the silicon zero bias p-type Schottky diode D1 is grounded, the 2 ends of the MA4E2200 silicon zero bias p-type Schottky diode D1 are connected to the resistor R6 and grounded, and the 2 ends of the silicon zero bias p-type Schottky diode D1 are connected to the capacitor C7 and grounded.

The input terminal 2 of the silicon zero bias p-type Schottky diode D1 is connected to the resistor R4 and connected to the op amp comparator U2A in the non-constant envelope loop control, the input terminal 3 of the op amp comparator U2A is connected to one end of the resistor R5, the other end of the resistor R5 is connected to the capacitor C6 and grounded, and the other end of the resistor R5 receives the non-constant envelope signal AM_mod, the input terminal 3 of the op amp comparator U2A is connected to the resistor R9 and grounded, the input terminal 3 of the op amp comparator U2A is connected to the capacitor C8 and grounded, and connected to the switch through the resistor R7. The 4th terminal of the op amp comparator U2A is grounded, the 8th terminal of the op amp comparator U2A is connected to a power supply with a voltage of 5V, the output terminal 1 of the op amp comparator U2A is connected to one end of the resistor R3, the other end of the resistor R3 is connected to the capacitor C5 and grounded, and the other end of the resistor R3 is connected to the switch. The capacitor C1 is connected between the output terminal 1 and the input terminal 2 of the op amp comparator U2A, and the resistor R1 is connected in parallel with the capacitor C1.

The switch adopts the ADG884 chip, the NC1 end of the ADG884 chip is connected to the other end of the resistor R3, and the NC2 end of the ADG884 chip is connected to the other end of the resistor R7.

The control signal APC_SW is connected to the IN2 terminal of the ADG884 chip through the resistor R11, and the IN2 terminal of the ADG884 chip is connected to the capacitor C13 and grounded; the control signal SW is also input to the IN2 terminal of the ADG884 chip, and the reference voltage APC is input to the COM2 terminal of the ADG884 chip. The COM1 terminal of the ADG884 chip is connected to the resistor R13 as the output terminal of the control loop, the NO1 terminal and the NO2 terminal of the switch are connected to the constant envelope loop control, the VCC terminal of the switch is connected to the capacitor C12 and grounded, and is connected to a power supply with a voltage of 5V, and the GND terminal of the switch is grounded.

The control signals APC_SW and SW are generated based on the mode of the multi-mode radio. When the multi-mode radio is in non-constant envelope mode, the ADG884 chip controls the reference voltage APC to access the non-constant envelope loop control; when the multi-mode radio is in constant envelope mode, the ADG884 chip controls the reference voltage APC to access the constant envelope loop control.

The mean detector uses the LT5581 chip. The input end of the control loop is connected to capacitor C14, resistor R12, and resistor R14 in sequence, and is connected to one end of capacitor C22 in the mean detector. The other end of capacitor C22 is connected to resistor R24 and grounded, and the other end of capacitor C22 is connected to one end of resistor R18. The other end of resistor R18 is connected to resistor R23 and grounded. The other end of resistor R18 is connected to one end of capacitor C21. The other end of capacitor C21 is respectively connected to one end of inductor L1 and capacitor C24. Capacitor C24 is grounded. The other end of inductor L1 is connected to capacitor C20 and the RFin end of the LT5581 chip, and the other end of inductor L1 is connected to resistor R22 and grounded.

The GND, GND2, GND3 and GND4 terminals of the LT5581 chip are grounded, the CSQ terminal of the LT5581 chip is connected to the capacitor C15 and grounded, the Vcc terminal and the EN terminal of the LT5581 chip are connected to a power supply with a voltage of 3V, and are respectively connected to the capacitors C18 and C19 and grounded, the Vout terminal of the LT5581 chip is connected to the capacitor C26 and grounded, the Vout terminal of the LT5581 chip is connected to one end of the resistor R21, and the other end of the resistor R21 is respectively connected to the resistor R20 and the capacitor C25, and the capacitor C25 is grounded. The LT5581 chip is used to receive a constant envelope signal and output a voltage signal proportional to the constant envelope signal on a linear scale.

In the constant envelope loop control, the input terminal 6 of the operational amplifier comparator U2B is connected to the resistor R20, the input terminal 5 of the operational amplifier comparator U2B is connected to the resistor R17 and grounded, the input terminal 5 of the operational amplifier comparator U2B is connected to the capacitor C16 and grounded, and the input terminal 5 of the operational amplifier comparator U2B is connected to the resistor R15 and then connected to the NO2 terminal of the switch, the output terminal 7 of the operational amplifier comparator U2B is connected to one end of the resistor R16, the other end of the resistor R16 is connected to the capacitor C17, the capacitor C17 is grounded, and the other end of the resistor R16 is connected to the NO1 terminal of the switch. Among them, the input terminal 6 and the output terminal 7 of the operational amplifier comparator U2B are connected through the resistor R19 and the capacitor C23, and the resistor R25 is connected in parallel with the resistor R19 and the capacitor C23.

Please refer to Figure 7, which is a waveform diagram of an embodiment of the predistortion power control and modulation of the RF excitation signal of the present application. The circuit in Figure 6 has been actually tested, and the predistortion power control and modulation of the RF excitation signal is shown in Figure 7.

The following table shows the distortion and transmission efficiency of the traditional single-loop power control and the solution of this application at different frequencies:

It can be seen from the above table that, compared with the traditional single-loop power control, the modulation of the scheme of the present application reduces the distortion at different frequency points, and optimizes the distortion of the RF excitation signal to about 2%, reaching a relatively high level.

Secondly, after adopting the solution of the present application, the transmission efficiency at different frequencies is improved; the overall efficiency is improved by about 24%.

The following table shows the frequency switching time and power overshoot at different frequencies under constant envelope signal conditions when the traditional single-loop power control and the solution of this application are applied to the PR9530 radio:

From the above table, it can be seen that the power overshoot and frequency switching time of the traditional single-loop power control and the solution of the present application are not much different, and both can meet the requirements of the indicators.

Different from the prior art, the control loop of the power control circuit 100 of the multi-mode radio station of the present application is provided with a constant envelope control loop 31 and a non-constant envelope control loop 32, which respectively perform power control on the constant envelope signal and the non-constant envelope signal of the multi-mode radio station, so that the power control circuit of the multi-mode radio station of the present application can meet the power control of the constant envelope and non-constant envelope signals. Moreover, compared with the prior art, the use of a dual control loop in the power control circuit 100 of the multi-mode radio station of the present application can greatly reduce the difficulty of the design algorithm of the multi-mode radio station power control, thereby reducing the cost of the multi-mode radio station power control.

Furthermore, the present application adopts a dual-loop power control method, using a mean detector 311 for fast detection of constant envelope signals to achieve closed-loop power control; and using a peak detector 321 for fast detection of non-constant envelope signals to achieve closed-loop power control, so that the power control circuit of the multi-mode radio station of the present application can meet the power control of constant envelope and non-constant envelope signals while reducing the difficulty of the design algorithm of the multi-mode radio station power control.

The present application also adopts a novel peak detector 321, which can effectively improve the transmission efficiency of the RF excitation signal and reduce the distortion under the same saturation power.

In summary, the power control circuit 100 of the multi-mode radio station of the present application can greatly reduce the difficulty of power control design of the multi-mode radio station; improve the transmission efficiency of the RF excitation signal, reduce distortion, and reduce the power control cost of the multi-mode radio station; and can realize frequency hopping power control.

The present application further proposes a multi-mode radio station. Please refer to FIG. 8 , which is a schematic structural diagram of an embodiment of the multi-mode radio station of the present application. The multi-mode radio station 200 of this embodiment includes the power control circuit 100 of any of the multi-mode radio stations described above.

The multi-mode radio station 200 of this embodiment can be a domestic tactical radio station in the air defense field, a 1.5-generation radio station, a 2-generation radio station, a single-soldier integrated terminal, etc., and is not limited here.

The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims (6)

1. A power control circuit for a multi-mode radio station, characterized in that the power control circuit comprises a power amplifier, a directional coupler, and a control loop; The power control circuit performs power control on the radio frequency excitation signal of the multi-mode radio station, and transmits the radio frequency excitation signal after power control through the antenna; Wherein, the output end of the radio frequency excitation signal is connected to the input end of the power amplifier; The output end of the power amplifier is connected to the input end of the directional coupler; The output end of the directional coupler is connected to the antenna, and the coupling end of the directional coupler is connected to the input end of the control loop; The output end of the control loop is connected to the input end of the power amplifier; Wherein, the control loop includes a constant envelope control loop, a non-constant envelope control loop and a switch, the input end of the switch inputs a reference voltage, the first output end of the switch is connected to the input end of the constant envelope control loop, and the second output end of the switch is connected to the input end of the non-constant envelope control loop; the constant envelope control loop is used to perform power control on the constant envelope signal; the non-constant envelope control loop is used to perform power control on the non-constant envelope signal; The non-constant envelope control loop includes an adjustable attenuator, a peak detector and a first operational amplifier comparator, wherein the input end of the adjustable attenuator is connected to the coupling end of the directional coupler, and the output end of the adjustable attenuator is connected to the input end of the peak detector; the first input end of the first operational amplifier comparator is connected to the output end of the peak detector, the second input end of the first operational amplifier comparator inputs the non-constant envelope signal, and the second input end of the first operational amplifier comparator is connected to the second output end of the switch, and the output end of the first operational amplifier comparator is connected to the input end of the power amplifier; The peak detector includes a second capacitor, a first resistor, a first diode, a second diode, a second resistor and a third capacitor; the first end of the second capacitor is connected to the output end of the adjustable attenuator; the first end of the first resistor is connected to the second end of the second capacitor; the forward end of the first diode is connected to the second end of the first resistor and grounded; the negative end of the first diode is connected to the second end of the second capacitor; the forward end of the second diode is respectively connected to the second end of the second capacitor and the negative end of the first diode; the first end of the second resistor is connected to the negative end of the second diode; the second resistor is connected to the first input end of the first operational amplifier comparator; the first end of the third capacitor is grounded, and the second end of the third capacitor is connected to the second end of the second resistor. 2. The power control circuit of the multi-mode radio station according to claim 1, wherein the non-constant envelope control loop further comprises: A first capacitor, wherein a first end of the first capacitor is connected to a first input end of the first operational amplifier comparator, and a second end of the first capacitor is connected to an output end of the first operational amplifier comparator. 3 . The power control circuit of a multi-mode radio station according to claim 1 , wherein the first diode and the second diode comprise Schottky diodes. 4. The power control circuit of the multi-mode radio station according to claim 1, wherein the constant envelope control loop comprises: A mean detector, the input end of the mean detector is connected to the coupling end of the directional coupler; A second operational amplifier comparator, wherein a first input terminal of the second operational amplifier comparator is connected to an output terminal of the mean detector, a second input terminal of the second operational amplifier comparator is connected to a first output terminal of the switch, and an output terminal of the second operational amplifier comparator is connected to an input terminal of the power amplifier. 5. The power control circuit of the multi-mode radio station according to claim 4, characterized in that the constant envelope control loop further comprises: a fourth capacitor, wherein a first terminal of the fourth capacitor is connected to a first input terminal of the second operational amplifier comparator; A third resistor, wherein a first end of the third resistor is connected to a second end of the fourth capacitor, and the third resistor is connected to an output end of the second operational amplifier comparator. 6. A multi-mode radio station, characterized in that the multi-mode radio station comprises the power control circuit of the multi-mode radio station according to any one of claims 1-5.