CN107911093A - Automatic growth control agc circuit, method and apparatus - Google Patents

Abstract

This application discloses a kind of automatic growth control agc circuit, method and apparatus, it is related to electronic technology field, is used for realization automatic growth control.Automatic growth control agc circuit includes：Controller, low-noise amplifier, variable gain amplification coupling circuit, power amplifier, the first analog-digital converter ADC, average power detection circuit, operational amplifier, the 2nd ADC.The embodiment of the present application is applied to reception of wireless signals.

Description

Automatic gain control AGC circuit, method and device

technical field

The present invention relates to the field of electronic technology, in particular to an automatic gain control (Automatic GainControl, AGC) circuit. Methods and Apparatus.

Background technique

When receiving radio frequency signals such as WIFI signals in the radio frequency signal receiving link, it needs to be amplified or attenuated and then converted to a digital signal through an analog-to-digital converter (Analog-to-Digital Converter, ADC), and finally the digital signal is processed demodulation. The signal strength of the Wireless Fidelity (Wireless Fidelity, WIFI) signal or interference signal changes at any time. If the amplification or attenuation of the RF signal receiving link adopts a fixed gain, when the signal strength of the RF signal or interference signal is high, it may cause ADC saturation, when the signal strength of the radio frequency signal or interference signal is small, it may lead to a decrease in the resolution of the ADC.

Contents of the invention

Embodiments of the present application provide an automatic gain control AGC circuit, method and device, so as to dynamically adjust the gain of a radio frequency signal receiving link.

In order to achieve the above object, the embodiments of the present application adopt the following technical solutions:

In the first aspect, an automatic gain control AGC circuit is provided, including: a controller, a low-noise amplifier, a variable gain amplification coupling circuit, a power amplifier, a first analog-to-digital converter ADC, an average power detection circuit, an operational amplifier, and a first Two ADCs; wherein, the input end of the low noise amplifier is used to receive radio frequency signals, and the output end of the low noise amplifier is connected to the first input end of the variable gain amplification coupling circuit; the variable gain amplification coupling circuit The direct output end of the power amplifier 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 first ADC; the output end of the first ADC is connected to the first input end of the controller; The coupling output end of the variable gain amplification coupling circuit is connected to the input end of the average power detection circuit; the output end of the average power detection circuit is connected to the input end of the operational amplifier; the output end of the operational amplifier is connected to the The input end of the second ADC; the output end of the second ADC is connected to the second input end of the controller; the output end of the controller is connected to the second input end of the variable gain amplification coupling circuit;

The low noise amplifier is used to receive radio frequency signals and amplify them;

The variable gain amplifying coupling circuit is used to attenuate the radio frequency signal according to the control signal of the controller; it is also used to output the coupling signal of the radio frequency signal through the coupling output port, and the coupling signal of the coupling signal the signal strength is proportional to the signal strength of the radio frequency signal;

The power amplifier is used to amplify the radio frequency signal;

The first ADC is used to perform analog-to-digital conversion on the radio frequency signal to obtain a first digital signal, and send it to the controller;

The average power detection circuit is used to detect the coupling signal to obtain an analog voltage signal;

The operational amplifier is used to amplify the analog voltage signal;

The second ADC is used to perform analog-to-digital conversion on the amplified analog voltage signal to obtain a second digital signal, and send it to the controller;

The controller is used to receive the second digital signal through the second ADC; and adjust the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit according to the second digital signal.

The second aspect provides an automatic gain control AGC method, which is applied to the AGC circuit described in the first aspect, the AGC circuit includes a variable gain amplification coupling circuit, and the method includes:

receiving a second digital signal;

Adjusting the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit according to the second digital signal.

In a third aspect, a controller is provided, which is applied to the AGC circuit as described in the first aspect, the AGC circuit includes a variable gain amplification coupling circuit, and the controller includes:

a receiving unit, configured to receive a second digital signal;

An adjustment unit, configured to adjust the attenuation value of the radio frequency signal by the variable gain amplification coupling circuit according to the second digital signal.

In a fourth aspect, there is provided a computer-readable storage medium storing one or more programs, the one or more programs include instructions, and the instructions, when executed by a computer, cause the computer to execute the method described in the second aspect. method.

The automatic gain control AGC circuit, method and device provided by the embodiments of the present application couple the radio frequency signal to obtain a coupling signal, the signal strength of the coupling signal is proportional to the signal strength of the radio frequency signal, and the coupling signal is detected to obtain an analog voltage signal, and the analog voltage signal is obtained by detecting the coupling signal. After the voltage signal is amplified, the analog-to-digital conversion is performed to obtain a digital signal, and the attenuation of the VGA on the main circuit is adjusted according to the digital signal, that is, the gain of the main circuit is adjusted according to the signal strength of the radio frequency signal, and the gain of the radio frequency signal receiving link is dynamically adjusted.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces the drawings that are required in the description of the embodiments or the prior art.

Fig. 1 is the first schematic diagram of the AGC circuit provided by the embodiment of the present application;

Fig. 2 is the second schematic diagram of the AGC circuit provided by the embodiment of the present application;

Fig. 3 is the waveform diagram of the WIFI signal and mean power detection that the embodiment of the application provides;

4 is a schematic diagram of waveforms without VGA attenuation and VGA attenuation provided by the embodiment of the present application;

FIG. 5 is a first schematic diagram of the timing sequence of an interference signal and a useful radio frequency signal provided by an embodiment of the present application;

FIG. 6 is a second schematic diagram of the timing sequence of an interference signal and a useful radio frequency signal provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of a time delay of an average power detection circuit provided by an embodiment of the present application;

Fig. 8 is a schematic flow diagram 1 of the AGC method provided by the embodiment of the present application;

FIG. 9 is a schematic flow diagram II of the AGC method provided by the embodiment of the present application;

FIG. 10 is a schematic flow diagram III of the AGC method provided by the embodiment of the present application;

FIG. 11 is a schematic structural diagram of a controller provided by an embodiment of the present application.

Detailed ways

Embodiments of the present application are described below in conjunction with the accompanying drawings.

The gain described in the embodiment of this application refers to the amplification factor. In electronics, it is usually the ratio of the output signal to the input signal of a system. For example, the antenna gain indicates the parameter of the radiation concentration of the directional antenna. The ratio of the square of the electric field intensity generated in the predetermined direction, the amplifier gain indicates the amplification factor of the amplifier power, expressed in common logarithm of the ratio of output power to input power, etc.

The automatic gain control (Automatic Gain Control, AGC) described in the embodiment of the present application refers to an automatic control method that automatically adjusts the gain of the amplifying circuit according to the signal strength. AGC is a kind of limiting output, which uses the effective combination of linear amplification and compression amplification to adjust the output signal. When a weak signal is input, the linear amplifying circuit works to ensure the strength of the output signal; when the input signal reaches a certain strength, the compression amplifying circuit is started to reduce the output amplitude. It can automatically control the magnitude of the gain by changing the input and output compression ratio. Therefore, the single-stage AGC can only limit the maximum output amplitude of the signal, and when the input signal is small enough, the output amplitude will decrease. In order to stabilize the output amplitude at a fixed value, it may be possible to use the simultaneous action of the limiting amplifier and AGC: that is, without the action of the AGC, the amplitude of the output signal is the same even when the input signal is the weakest. It should exceed the required fixed value, and then adjust the output amplitude to the required fixed value through AGC control, that is, generally the input signal is multi-stage amplified, and the signal of the last stage amplifier is rectified and filtered to control the DC level of the first stage. The output of the first stage amplifier.

An embodiment of the present application provides an AGC circuit. Referring to FIG. 1 , the AGC circuit includes: a controller 100, a low noise amplifier 101, a variable gain amplifier coupling circuit 102, a power amplifier 103, and a first analog-to-digital converter (Analog-to-Digital Converter, ADC) 104 , average power detection circuit 105 , operational amplifier 106 , second ADC 107 , comparator 108 .

Wherein, the input end of low noise amplifier 101 is used for receiving radio frequency signal, the output end of low noise amplifier 101 is connected the first input end of variable gain amplifier coupling circuit 102; The direct output end of variable gain amplifier coupling circuit 102 is connected power amplifier The input end of 103; The output end of power amplifier 103 connects the input end of first ADC 104; The output end of first ADC104 connects the first input end of controller; The coupling output end of variable gain amplification coupling circuit 102 connects mean power detection The input end of circuit 105; The output end of mean power detection circuit 105 is connected the input end of operational amplifier 106; The output end of operational amplifier 106 is connected the input end of second ADC 107; The output end of second ADC 107 is connected the second of controller Input terminal; the output terminal of the controller is connected to the second input terminal of the variable gain amplification coupling circuit 102; input. Wherein, the main circuit includes a path formed by a low noise amplifier 101 , a variable gain amplifier coupling circuit 102 , a power amplifier 103 , and a first ADC 104 .

The main working principle of the circuit of the embodiment of the present application is: the radio frequency signal passes through the low noise amplifier 101, the variable gain amplifier coupling circuit 102, the power amplifier 103, and the first ADC 104 to the controller 100, and then the controller 100 decodes it. Tune. The average power detection circuit 105 detects the magnitude of the radio frequency signal and sends it to the controller 10100. The controller 100 controls the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit 102 according to the detection result, thereby adjusting the low noise amplifier 101, variable The gain amplifies the gain of the main circuit where the coupling circuit 102 , the power amplifier 103 , and the first ADC 104 are located. specific:

LNA 101

The low noise amplifier 101 refers to an amplifier with a very low noise figure. It is generally used as a high-frequency or intermediate-frequency preamplifier for various radio receivers, and an amplifying circuit for high-sensitivity electronic detection equipment. When a weak signal is amplified, the noise of the amplifier itself may seriously interfere with the signal, and the low noise amplifier 101 can reduce this noise to improve the signal-to-noise ratio of the output. In the embodiment of the present application, the low noise amplifier 101 is used to receive a radio frequency signal through an input terminal, and amplify the radio frequency signal to improve the signal-to-noise ratio. The radio frequency signal may include modulated signals with a peak-to-average ratio such as Wireless Fidelity (Wireless Fidelity, WIFI), Long Term Evolution (Long Term Evolution, LTE), Worldwide Interoperability for Microwave Access (Worldwide Interoperability for Microwave Access, WIMAX), and the like. In this embodiment of the present application, a WIFI signal is taken as an example for description.

Variable gain amplifier coupling circuit 102

The variable gain amplifying coupling circuit 102 is used to attenuate the radio frequency signal according to the control signal of the controller 100; it is also used to output the coupling signal of the radio frequency signal through the coupling output port, and the signal strength of the coupling signal is proportional to the signal strength of the radio frequency signal.

Referring to FIG. 2 , the variable gain amplifier coupling circuit 102 may include a first variable gain amplifier (Variable Gain Amplifier, VGA) 1021 , a coupler 1022 and a second VGA 1023 . The output end of the low noise amplifier 101 is connected to the input end of the first VGA 1021; The output end of the first VGA 1021 is connected to the input end of the coupler 1022; The coupling output terminal of the second VGA 1023 is connected to the input terminal of the power amplifier 103 as the output terminal of the variable gain amplification coupling circuit 102 as the coupling output terminal of the variable gain amplification coupling circuit 102; input. It should be noted that although only two VGAs are described in the example, the present application does not limit the number of VGAs, there may be one or more, and when there are more than one, the overall attenuation range is larger. In addition, the present application does not limit the series sequence of the VGA and the coupler, as long as the coupled signal output by the coupler meets the input range of the average power detection circuit 105, for example, the coupler 103 can also be located after the VGA 1023 or after the VGA Before 1021.

VGA 1021 and VGA 1023

The VGA 1021 and the VGA 1023 are used to amplify or attenuate the input radio frequency signal according to the control signal of the controller 100 . It can change the gain of the main circuit, adjust the dynamic range of the signal, and stabilize the output signal power. VGA controls the size of the gain through the high and low levels of the external digital signal. The steps to adjust the gain usually include 0.5dB, 1dB, 2dB, 4dB, 8dB and 16dB. The maximum attenuation value can achieve -31.5dB. If the maximum gain is about 18dB without attenuation, that is, the gain range is -31.5 dB ~ 18dB. In the embodiment of this application, its attenuation function is mainly used.

Coupler 1022

The coupler 1022 includes a straight-through path and a coupling path, wherein the straight-through path is used to pass the radio frequency signal, and the coupling path is used to generate a coupled signal of the radio frequency signal, and the signal strength of the coupled signal is proportional to the signal strength of the radio frequency signal, so by measuring the coupled signal The magnitude of the RF signal can be measured indirectly.

Power Amplifier 103

The power amplifier 103 is used to amplify the radio frequency signal to a range suitable for the input voltage of the first ADC 104 when the power of the radio frequency signal is low.

First ADC 104

The first ADC 104 is used to perform analog-to-digital conversion on the radio frequency signal to obtain a first digital signal, and send it to the controller 100 . It is specifically used to convert time-continuous and amplitude-continuous analog signals into time-discrete and amplitude-discrete digital signals. Therefore, analog-to-digital conversion generally goes through four processes: sampling, holding, quantization, and encoding. In actual circuits, some of these processes are combined, for example, sampling and holding, quantization and encoding are often implemented simultaneously in the conversion process. The first ADC 104 may be an 80MSPS chip with an 8bit sampling rate.

Average power detection circuit 105

The average power detection circuit 105 can be an average power detection circuit using a root mean square detector, which can be used for signal power detection of arbitrary waveforms. The root mean square detector is an output voltage response device that has nothing to do with the input signal waveform. In the embodiment of the present application, the average power detection circuit 105 is used to detect the coupling signal to obtain an analog voltage signal.

Due to the frame structure characteristics of the WIFI signal, the gain must be locked and kept constant within a very short period of the preamble. Generally, the entire process is required to be completed within 1us of the traditional short training field (Legacy Short Training Field, L-STF) part. The duration and accuracy of the average power detection will directly determine the total time of the AGC. In addition, since the WIFI signal adopts the modulation method of Orthogonal Frequency Division Multiplexing (OFDM), the peak-to-average ratio is very high. If the peak or logarithmic power detection method is used, the output voltage signal will vary with The peak value of the input RF signal varies with each other, and the actual power cannot be prepared to be detected. It directly affects the realization of subsequent judgment and control mechanisms.

The average power detection circuit 105 is designed with the delay as the main index, and the accuracy and dynamic range as the secondary indexes. The size of the delay is a key indicator that directly affects whether the entire AGC architecture can meet the requirements. The dynamic range and accuracy index are considered under the index of meeting the smaller delay time. The larger the dynamic range, the higher the detection sensitivity; the higher the accuracy, the smaller the probability of misjudgment. Referring to FIG. 3 , FIG. 3A is a time-domain waveform of a WIFI signal, and FIG. 3B is a waveform diagram of a corresponding analog voltage signal output by the average power detection circuit 105 . The average power detection adopts the calculation method of true root mean square value (also called true effective value), and the average power detection circuit 105 can specifically be realized by calculation of a dedicated chip or a field programmable gate array (Field Programmable Gate Array, FPGA). The application examples are not limited.

op amp 106

The operational amplifier 106 ("op amp" for short) is a circuit unit with a very high amplification factor. In actual circuits, some kind of functional module is usually combined with a feedback network. It is an amplifier with a special coupling circuit and feedback. Its output signal can be the result of mathematical operations such as addition, subtraction, or differentiation and integration of the input signal. In the embodiment of the present application, it can be used to amplify the analog voltage signal output by the average power detection circuit 105 to a range suitable for the input voltage of the second ADC 107 .

Second ADC 107

The second ADC 107 is used for converting the amplified analog voltage signal output by the operational amplifier 106 into a second digital signal after analog-to-digital conversion, and sending it to the controller 100 . The second ADC 107 may be an 80MSPS chip with an 8bit sampling rate.

Controller 100

The controller 100 may be a digital signal processing (Digital Signal Processing, DSP), a field programmable gate array (Field Programmable Gate Array, FPGA), a complex programmable logic device (Complex Programmable Logic Device, CPLD), a central processing unit (Central Processing Unit , CPU) etc. In this embodiment of the present application, an FPGA is taken as an example for description.

The controller 100 is used for receiving the second digital signal through the second ADC 107 ; and adjusting the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit 102 according to the second digital signal, so as to control the gain of the main circuit.

The automatic control loop in the entire AGC circuit mainly takes the controller 100 as the core, and the controller 100 compares it with an internal threshold value after receiving the second digital signal. If the second digital signal is less than or equal to the threshold value, adjust the attenuation value of the variable gain amplifier coupling circuit to 0 for the radio frequency signal to maintain the maximum gain, that is, adjust the attenuation value of the first VGA 1021 and the second VGA 1023 for the radio frequency signal is 0; if the second digital signal is greater than the threshold value, the controller 100 adjusts the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit 102 according to the difference between the second digital signal and the threshold value. For the scenario shown in Figure 2, since the maximum attenuation value of the first VGA 1021 is -31.5dB, when the difference exceeds 31.5dB, the attenuation value of the second VGA 1023 is controlled, so a maximum attenuation value of 63dB can be achieved. decay value.

Since the WIFI signal is a Time Division Duplex (TDD) system, and the signal changes in real time, when a frame of the receiving link ends, it will switch to the sending link. At this time, the variable gain amplification coupling should be controlled The circuit 102 has an attenuation value of 0 for the radio frequency signal, keeps it at the maximum gain, waits for the next frame to be received and re-forms the AGC control loop.

The waveform tested when the normal radio frequency signal is not attenuated by the variable gain amplifier coupling circuit 102 is shown in FIG. 4A . When the control loop is formed, the waveform of the radio frequency signal is found through the test as shown in FIG. 4B .

Interference signal processing

In addition, due to the wide application of WIFI, there are more or less interference signals in most of the existing application locations, and the interference here includes interference from other WIFI signals and interference from non-WIFI signals. Referring to Figure 5, if a useful RF signal is received first and the AGC is adjusted, a stronger interference signal arrives, in order to protect each device, the AGC should be readjusted. Therefore, it may cause that the locked useful radio frequency signal cannot be demodulated. As shown in Figure 6, if a strong interference signal is received first and the AGC is adjusted, the useful signal of the useful RF signal with a lower intensity arrives, and the current gain can only be maintained and demodulated without readjusting the AGC, which may sacrifice part of the performance. Because if the useful radio frequency signal is to be kept at the optimum gain, the interference signal will inevitably be larger, causing the first ADC 104 to tend to be saturated.

Large Signal Protection

Due to the uncertainty of external signals, there may be many large WIFI signals and large non-WIFI signals. In order to ensure that the first ADC 104 will not be damaged, this large signal should be quickly judged and attenuated. This application realizes this function through a comparator.

Comparator 108

The comparator 108 is used for quickly comparing and judging the received high-power signal, so as to prevent the first ADC 104 from being damaged due to excessive input signal power. If the analog voltage signal output by the average power detection circuit 105 is greater than the threshold of the comparator 108, the comparator outputs a comparison result signal, for example, a high level signal. It should be noted that the comparator 108 is optional in this application.

The controller 100 is also used to adjust the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit 102 to the maximum if the comparison result signal of the comparator 108 is received, and can control the attenuation value of the entire VGA to the maximum or control the attenuation value of a part of the VGA to the maximum. maximum. For example, assume that the threshold value of the comparator 108 is set to a voltage value corresponding to -10 dBm. If the comparator 108 outputs a high level, the controller 100 quickly controls the attenuation value of the first VGA 1021 to be the maximum, which is equivalent to attenuating the radio frequency signal by 31.5dB.

Latency Verification

For the AGC circuit of the WIFI signal, the most important thing is to ensure that the control is completed with a sufficiently low delay. As shown in FIG. 7 , the time delay of the analog voltage signal detected by the average power detection circuit 105 for the WIFI radio frequency signal is about 100 ns.

The time delay inside the FPGA is mainly the comparison between the second digital signal and the threshold value, and the output time delay of outputting control signals to the first VGA 1021 and the second VGA 1023 , which is about 100 ns.

In addition, the second ADC 107 is a clock with a sampling frequency of 80MHz, the cycle of the clock signal is 1/80MHz=12.5ns, and its fixed delay is a clock signal of 4 cycles, so the delay of the second ADC 107 is 12.5ns*4 = 50ns.

The total time delay is 100ns+100ns+50ns=250ns, which meets the design requirements of WIFI.

Scheme Comprehensive Verification

Finally, the whole circuit is used to test WIFI signals with different input powers, and the response speed and control function of the AGC circuit can be tested from -95dBm to -10dBm.

Starting from the power of -95dBm, the signal is gradually increased, and the step is 1dB, and the signal level of the first ADC 104 of the main circuit passing through the FPGA is tested. When the RF signal power is -50dBm, the AGC loop starts to work, and when the signal power is greater than -50dBm, the first VGA 1021 and the second VGA 1023 start to increase the attenuation value, the total gain gradually decreases, and the first ADC 104 is guaranteed The input level remains unchanged.

Starting from the power of -10dBm, the signal is gradually reduced, and the step is 1dB, and the signal level of the first ADC 104 of the main circuit passing through the FPGA is tested. The first VGA 1021 and the second VGA 1023 start to reduce the attenuation value, the total gain gradually increases, and ensure that the input level of the first ADC 104 remains unchanged. When the signal power is -50dBm, the attenuation values of the first VGA 1021 and the second VGA 1023 are 0, and the total gain is the largest. When the signal power is less than -50dBm, keep working with maximum gain.

Large signal verification. The power is kept at -50dBm in the initial state, and when the power is suddenly changed to 0dBm, the output state of the test comparator 108 is high and the attenuation value of the first VGA 1021 is -31.5dB.

The automatic gain control AGC circuit provided by the embodiment of the present application couples the radio frequency signal to obtain a coupled signal, the signal strength of the coupled signal is proportional to the signal strength of the radio frequency signal, detects the coupled signal to obtain an analog voltage signal, and amplifies the analog voltage signal Afterwards, analog-to-digital conversion is performed to obtain a digital signal, and the attenuation of the VGA on the main circuit is adjusted according to the digital signal, that is, the gain of the main circuit is adjusted according to the signal strength of the radio frequency signal, and the gain of the radio frequency signal receiving link is dynamically adjusted.

It should be noted that the average power detection and VGA circuit described in the embodiment of the present application can also be applied to power detection and adjustment at the output end of a power amplifier (Power Amplifier, PA) in the transmission link, so as to keep the output signal at a constant power value .

The embodiment of the present application also provides an AGC method, which is applied to the above-mentioned AGC circuit. Referring to FIG. 8, the method includes:

S101. Receive a second digital signal.

S102. Adjust the attenuation value of the radio frequency signal by the variable gain amplification coupling circuit according to the second digital signal.

In a possible design, referring to what is shown in FIG. 9, step S102 specifically includes:

S1021. Compare the second digital signal with a threshold value.

S1022. If the second digital signal is less than or equal to the threshold value, adjust the attenuation value of the variable gain amplifier coupling circuit to 0 to attenuate the radio frequency signal.

S1023. If the second digital signal is greater than the threshold value, adjust the attenuation value of the radio frequency signal by the variable gain amplification coupling circuit according to the difference between the second digital signal and the threshold value.

In a possible design, referring to Fig. 10, the method further includes:

S103. If the comparison result signal from the comparator is received, adjust the attenuation value of the radio frequency signal by the variable gain amplification coupling circuit to the maximum.

The embodiment of the present application also provides a controller, which is applied to the above-mentioned AGC circuit. Referring to FIG. 11, the controller 100 includes:

a receiving unit 1001, configured to receive a second digital signal;

The adjustment unit 1002 is configured to adjust the attenuation value of the radio frequency signal by the variable gain amplification coupling circuit according to the second digital signal.

In a possible design, the adjustment unit 1102 is specifically configured to: compare the second digital signal with a threshold value; if the second digital signal is less than or equal to the threshold value, adjust the variable gain amplification coupling circuit to The attenuation value of the radio frequency signal is 0; if the second digital signal is greater than the threshold value, adjust the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit according to the difference between the second digital signal and the threshold value.

In a possible design, the adjustment unit 110 is further configured to: adjust the attenuation value of the radio frequency signal by the variable gain amplification coupling circuit to the maximum if the comparison result signal of the comparator is received.

Since the controller in the embodiment of the present application can be applied to the above-mentioned AGC circuit, the technical effect it can obtain can also refer to the above-mentioned embodiment, and the embodiment of the present application will not repeat it here.

An embodiment of the present application provides a computer-readable storage medium that stores one or more programs, and the one or more programs include instructions that, when executed by a computer, cause the computer to perform the operations shown in Figures 8-10. described method.

It should be understood that, in various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the order of execution, and the execution order of the processes should be determined by their functions and internal logic, and should not be used in the embodiments of the present application. The implementation process constitutes any limitation.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit.

In the above embodiments, all or part of them may be implemented by software, hardware, firmware or any combination thereof. When implemented using a software program, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the processes or functions according to the embodiments of the present application will be generated in whole or in part. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website, computer, server, or data center Transmission to another website site, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer, or may be a data storage device including one or more servers, data centers, etc. that can be integrated with the medium. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, or a magnetic tape), an optical medium (eg, DVD), or a semiconductor medium (eg, a solid state disk (Solid State Disk, SSD)) and the like.

The above is only a specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application. Should be covered within the protection scope of this application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims (11)

1. An automatic gain control AGC circuit is characterized in that, comprising: controller, low noise amplifier, variable gain amplifier coupling circuit, power amplifier, the first analog-to-digital converter ADC, average power detection circuit, operational amplifier, the first Two ADCs; wherein, the input end of the low noise amplifier is used to receive radio frequency signals, and the output end of the low noise amplifier is connected to the first input end of the variable gain amplification coupling circuit; the variable gain amplification coupling circuit The direct output end of the power amplifier 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 first ADC; the output end of the first ADC is connected to the first input end of the controller; The coupling output end of the variable gain amplification coupling circuit is connected to the input end of the average power detection circuit; the output end of the average power detection circuit is connected to the input end of the operational amplifier; the output end of the operational amplifier is connected to the The input end of the second ADC; the output end of the second ADC is connected to the second input end of the controller; the output end of the controller is connected to the second input end of the variable gain amplification coupling circuit; The low noise amplifier is used to receive radio frequency signals and amplify them; The variable gain amplifying coupling circuit is used to attenuate the radio frequency signal according to the control signal of the controller; it is also used to output the coupling signal of the radio frequency signal through the coupling output port, and the coupling signal of the coupling signal the signal strength is proportional to the signal strength of the radio frequency signal; The power amplifier is used to amplify the radio frequency signal; The first ADC is used to perform analog-to-digital conversion on the radio frequency signal to obtain a first digital signal, and send it to the controller; The average power detection circuit is used to detect the coupling signal to obtain an analog voltage signal; The operational amplifier is used to amplify the analog voltage signal; The second ADC is used to perform analog-to-digital conversion on the amplified analog voltage signal to obtain a second digital signal, and send it to the controller; The controller is used to receive the second digital signal through the second ADC; and adjust the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit according to the second digital signal. 2. The circuit according to claim 1, wherein the variable gain amplifier coupling circuit comprises a coupler, a first VGA and a second VGA, wherein the output terminal of the low noise amplifier is connected to the first The input end of VGA; The output end of the first VGA is connected to the input end of the coupler; The straight-through output end of the coupler is connected to the input end of the second VGA, and the coupled output end of the coupler is used as the input end of the coupler The coupling output end of the variable gain amplification coupling circuit is connected to the input end of the average power detection circuit; the output end of the second VGA is connected to the input of the power amplifier as the direct output end of the variable gain amplification coupling circuit end. 3. The circuit according to claim 1, wherein the controller is specifically used for: comparing the second digital signal with a threshold value; If the second digital signal is less than or equal to the threshold value, adjusting the attenuation value of the radio frequency signal by the variable gain amplification coupling circuit to 0; If the second digital signal is greater than the threshold value, adjusting the attenuation of the radio frequency signal by the variable gain amplifier coupling circuit according to the difference between the second digital signal and the threshold value value. 4. The circuit according to claim 1, wherein the AGC circuit further comprises a comparator, the output terminal of the average power detection circuit is also connected to the input terminal of the comparator, and the comparator is connected to the The third input terminal of the controller, if the output signal of the average power detection circuit is greater than the threshold of the comparator, the comparator outputs a comparison result signal; The controller is further configured to adjust the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit to a maximum if the comparison result signal of the comparator is received. 5. An automatic gain control AGC method is characterized in that, being applied to the AGC circuit according to any one of claims 1-4, the AGC circuit comprises a variable gain amplification coupling circuit, and the method comprises: receiving a second digital signal; Adjusting the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit according to the second digital signal. 6. The method according to claim 5, wherein adjusting the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit according to the second digital signal comprises: comparing the second digital signal with a threshold value; If the second digital signal is less than or equal to the threshold value, adjusting the attenuation value of the variable gain amplifier coupling circuit to attenuate the radio frequency signal to 0; If the second digital signal is greater than the threshold value, adjusting the attenuation of the radio frequency signal by the variable gain amplifier coupling circuit according to the difference between the second digital signal and the threshold value value. 7. method according to claim 5, is characterized in that, described AGC circuit also comprises comparator, described method also comprises: If the comparison result signal of the comparator is received, the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit is adjusted to the maximum. 8. A controller, characterized in that it is applied to the AGC circuit according to any one of claims 1-4, the AGC circuit includes a variable gain amplification coupling circuit, and the controller includes: a receiving unit, configured to receive a second digital signal; An adjustment unit, configured to adjust the attenuation value of the radio frequency signal by the variable gain amplification coupling circuit according to the second digital signal. 9. The controller according to claim 8, wherein the adjustment unit is specifically used for: comparing the second digital signal with a threshold value; If the second digital signal is less than or equal to the threshold value, adjusting the attenuation value of the radio frequency signal by the variable gain amplification coupling circuit to 0; If the second digital signal is greater than the threshold value, adjusting the attenuation of the radio frequency signal by the variable gain amplifier coupling circuit according to the difference between the second digital signal and the threshold value value. 10. The controller according to claim 8, wherein the AGC circuit further comprises a comparator, and the adjustment unit is also used for: If the comparison result signal of the comparator is received, the attenuation value of the radio frequency signal by the variable gain amplifier coupling circuit is adjusted to the maximum. 11. A computer-readable storage medium storing one or more programs, wherein the one or more programs comprise instructions, which when executed by a computer cause the computer to perform the any one of the methods described.