A radio frequency front-end circuit with adaptive amplitude and phase weighting

Abstract

The present application belongs to the technical field of radio frequency front-end circuits, and relates to an adaptive amplitude-phase weighted radio frequency front-end circuit, including: a dual-channel module and a control module; the dual-channel module includes: a voltage-controlled phase shifter, a power combiner, a coupler, and a detector connected in sequence; one corresponding end of the two voltage-controlled phase shifters is respectively connected to the two input ports of the radio frequency front end, and the other corresponding end is connected to the coupler through the power combiner to divide the circuit passing through the coupler into two channels, one channel is connected to the output port of the radio frequency front end, and the other channel is connected to the detector to output the detection voltage of the detection signal; the control module outputs a bias voltage, performs phase shift control on the two voltage-controlled phase shifters, and obtains the current detection voltage; compares the current detection voltage with the previous detection voltage to obtain a bias voltage that makes the amplitude of the detection signal smaller. The present application can realize adaptive suppression of unknown repressive strong electromagnetic interference at the radio frequency front end.

Description

Technical Field

[0001] The present application relates to the technical field of radio frequency front-end circuits, and in particular to a radio frequency front-end circuit with adaptive amplitude and phase weighting. Background Art

[0002] With the rapid development of electronic information technology, electronic information equipment is developing in the direction of miniaturization and integration. The degree of refinement of internal devices in electronic information systems is constantly deepening, and the electromagnetic sensitivity is gradually increasing. At the same time, the rapid development of radio technology has led to a sharp increase in the number of electronic information equipment, resulting in an increasingly complex electromagnetic environment in space. Highly sensitive electronic information systems are susceptible to interference from unknown electromagnetic interference signals such as electromagnetic waves emitted by high-power devices on the same platform and other radio equipment in space, resulting in saturation compression in the amplification link, affecting the normal functioning of the system. As the front door of the electronic information system, the RF front end is the main way for electromagnetic interference to couple into the internal electronic information system. Suppressing electromagnetic interference at the RF front end is the key to preventing the electronic information system from entering a saturated state, which is conducive to the normal operation of the electronic information system under electromagnetic interference.

[0003] In the prior art, array beamforming technology is often used, and the main implementation schemes include: array beamforming anti-interference algorithm type and array beamforming anti-interference circuit type. Among them:

[0004] Array beamforming anti-interference algorithm type uses an algorithm based on digital signal processing technology to obtain the angle of arrival information of the interference signal, and then controls the RF T / R components of the analog phased array to perform beamforming based on the angle of arrival information of the interference signal, so that its radiation pattern forms a null in the direction of the interference signal wave, thereby achieving the purpose of suppressing interference.

[0005] Array beamforming anti-interference circuits use pure hardware circuits such as orthogonal couplers, phase shifters, and multi-phase filters to perform amplitude and phase weighted control on strong electromagnetic interference signals of multiple RF channels, so that the main lobe of the array beam is aligned with the direction of the expected signal so that the expected signal is constructively added, and at the same time, the null of the array beam is aligned with the direction of the interference signal so that the electromagnetic interference signal is greatly suppressed.

[0006] However, the prior art has the following disadvantages:

[0007] Array beamforming anti-interference algorithms can effectively suppress low-power interference; however, when the RF front end faces high-power suppressive strong electromagnetic saturation interference, the power-sensitive devices of the RF front end of the receiving link, such as low-noise amplifiers and mixers, will enter the saturation state due to excessive input power, and gain compression will cause the useful signal to be submerged in the strong electromagnetic interference, so it cannot cope with the suppressive strong electromagnetic interference.

[0008] Array beamforming anti-interference circuit type, the interference suppression circuit is designed at the RF front end to suppress the interference before entering the digital back end. It can have a good suppression effect on the suppressed saturation electromagnetic interference with known incoming wave direction; however, the circuit has poor flexibility and it is difficult to adjust the spatial null position, that is, it is difficult to achieve adaptive interference suppression, and there are disadvantages such as complex circuit structure, large size and narrow working bandwidth. Summary of the invention

[0009] Based on this, it is necessary to provide an adaptive amplitude-phase weighted RF front-end circuit to address the above technical problems, which can achieve adaptive suppression of unknown suppressive strong electromagnetic interference at the RF front end.

[0010] An adaptive amplitude-phase weighted radio frequency front-end circuit comprises: a dual-channel module and a control module connected to each other;

[0011] The dual-channel module includes: a voltage-controlled phase shifter, a power combiner, a coupler, and a detector connected in sequence; the number of the voltage-controlled phase shifters is two, one corresponding end of the two voltage-controlled phase shifters is respectively connected to the two input ports of the radio frequency front end, and the other corresponding end is connected to the coupler through the power combiner, so as to divide the circuit passing through the coupler into two channels, one channel is connected to the output port of the radio frequency front end, and the other channel is connected to the detector to output the detection voltage of the detection signal;

[0012] The control module outputs a bias voltage, performs phase shift control on two voltage-controlled phase shifters, and obtains a corresponding detection voltage as a current detection voltage; compares the current detection voltage with the previous detection voltage, obtains an optimal detection voltage that makes the amplitude of the detection signal smaller, and outputs a corresponding bias voltage in real time to achieve adaptive amplitude-phase weighting.

[0013] In one embodiment, the control module includes: a field programmable gate array, a digital-to-analog converter, and an analog-to-digital converter;

[0014] The digital-to-analog converter is connected to the field programmable gate array and the voltage-controlled phase shifter to output a bias voltage to adjust the two voltage-controlled phase shifters under the control of the field programmable gate array;

[0015] The analog-to-digital converter is connected to the field programmable gate array and the detector to collect the detection voltage output by the detector under the control of the field programmable gate array.

[0016] In one embodiment, the field programmable gate array controls the digital-to-analog converter to output the bias voltage according to different step values, and sets the corresponding clock according to the response time of the dual-channel module and the conversion time of the analog-to-digital converter, so that the bias voltage corresponds one-to-one to the corresponding detection voltage after phase shifting.

[0017] In one embodiment, the system further includes: a conditioning module disposed between the control module and the voltage-controlled phase shifter to linearly regulate the range of the bias voltage to within the voltage range required by the voltage-controlled phase shifter.

[0018] In one embodiment, the conditioning module includes: a power supply part and a conditioning part;

[0019] The power supply part provides power for the active circuit part, and the conditioning part linearly amplifies the input voltage from 0 to 5V to 0 to 14V.

[0020] In one embodiment, the dual-channel module further includes: a low noise amplifier disposed between the output port and the coupler to compensate for insertion loss and reduce attenuation of the desired signal.

[0021] In one embodiment, the dual-channel module further comprises: an adjustable low noise amplifier disposed between the detector and the coupler to ensure that the power of the signal is within the working range of the detector.

[0022] In one embodiment, the adjustable low noise amplifier comprises: two low noise amplifiers and an attenuator;

[0023] A low noise amplifier has a collector and an emitter connected to the coupler, and a base connected to one end of the attenuator;

[0024] The collector and emitter of another low noise amplifier are both connected to the other end of the attenuator, and the base is connected to the detector.

[0025] In one embodiment, the attenuation value of the attenuator is adjustable, so that the gain factor of the adjustable low noise amplifier can be adjusted by adjusting the attenuation value of the attenuator.

[0026] The above-mentioned adaptive amplitude-phase weighted RF front-end circuit adopts the idea of ​​dual-channel interference anti-phase synthesis cancellation, and uses FPGA to compare the amplitude of the cancellation synthesis output signal under different phase weightings to give the optimal phase weight, thereby realizing adaptive amplitude-phase weighted interference suppression, and can cope with high-power suppressive strong electromagnetic saturation interference, and has the ability to adaptively suppress unknown suppressive strong electromagnetic interference; a low-noise amplifier is used to compensate for the link loss of the signal, and it has the characteristic of no insertion loss; in addition, the combination of the detector and FPGA is adopted, and the adaptive interference suppression function does not depend on the specific interference frequency point, and it also has the advantages of adaptability, large interference power suppression, wide working bandwidth, simple circuit structure, miniaturization, low cost, etc., and has broad application prospects in the RF front end. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1It is a structural schematic diagram of a radio frequency front-end circuit with adaptive amplitude and phase weighting in one embodiment;

[0028] Figure 2 It is a schematic structural diagram of an adjustable low noise amplifier of a radio frequency front-end circuit with adaptive amplitude and phase weighting in one embodiment;

[0029] Figure 3 It is a schematic diagram of the architecture of a radio frequency front-end circuit with adaptive amplitude and phase weighting in one embodiment;

[0030] Figure 4 A control flow chart of a radio frequency front-end circuit with adaptive amplitude and phase weighting in one embodiment;

[0031] Figure 5 An S parameter test diagram of a radio frequency front-end circuit with adaptive amplitude and phase weighting in one embodiment;

[0032] Figure 6 This is a test diagram of the interference suppression capability of a radio frequency front-end circuit with adaptive amplitude and phase weighting in one embodiment.

[0033] Reference numerals:

[0034] Dual-channel module 1, voltage-controlled phase shifter A, power combiner B, coupler C, adjustable low-noise amplifier D, detector E, low-noise amplifier F;

[0035] Control module 2;

[0036] Conditioning module 3;

[0037] Input port one is RFIN1, input port two is RFIN2, and output port is RFOUT. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0039] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0040] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "multiple groups" means at least two groups, such as two groups, three groups, etc., unless otherwise clearly and specifically defined.

[0041] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0043] The present application provides a radio frequency front-end circuit with adaptive amplitude and phase weighting, such as Figure 1 and Figure 2 As shown, in one embodiment, it includes: a dual-channel module and a control module, and the dual-channel module is connected to the control module.

[0044] The dual-channel module includes: a voltage-controlled phase shifter, a power combiner, a coupler and a detector. There are two voltage-controlled phase shifters, one corresponding end of each of the two voltage-controlled phase shifters is connected to two input ports (i.e., input port 1 and input port 2) of the RF front end, and the other corresponding end is connected to the power combiner to output two phase-shifted signals and form a phase difference of 180°; the input end of the power combiner is connected to the two voltage-controlled phase shifters, and the output end is connected to the coupler to output a synthesized signal; the input end of the coupler is connected to the power combiner, and the output end is divided into two channels, one channel is connected to the output port of the RF front end, and the other channel is connected to the detector to output two coupled signals, wherein one coupled signal is the output signal and the other coupled signal is the detection signal; the input end of the detector is connected to the coupler, and the output end is connected to the control module to detect the envelope amplitude value of the detection signal and output the detection voltage (DC) of the detection signal. It should be noted that the dual-channel module is also provided with a plurality of interactive pin interfaces for powering active devices and connecting bias voltages. Such interfaces belong to the prior art and will not be described in detail here.

[0045] The control module outputs a bias voltage, performs phase shift control on two voltage-controlled phase shifters, and obtains a corresponding detection voltage as a current detection voltage; at the same time, the control module compares the current detection voltage with the previous detection voltage to obtain an optimal detection voltage that makes the amplitude of the detection signal smaller (specifically, the detection voltage that makes the amplitude of the detection signal smaller between the current detection voltage and the previous detection voltage is used as the optimal detection voltage, that is, if the current detection voltage makes the amplitude of the detection signal smaller, the current detection voltage is used as the optimal detection voltage, and if the previous detection voltage makes the amplitude of the detection signal smaller, the previous detection voltage is used as the optimal detection voltage), and outputs a bias voltage corresponding to the optimal detection voltage in real time to achieve adaptive amplitude-phase weighting.

[0046] Preferably, the control module includes: a field programmable gate array (FPGA), a digital-to-analog converter (DA) and an analog-to-digital converter (AD); the field programmable gate array (FPGA) is connected to the digital-to-analog converter (DA) and the analog-to-digital converter (AD) respectively to control the digital-to-analog converter (DA) to output a bias voltage and control the analog-to-digital converter (AD) to collect the detection voltage; the digital-to-analog converter (DA) is connected to the field programmable gate array and the voltage-controlled phase shifter to convert the output value of the field programmable gate array into a DC bias voltage and output it under the control of the field programmable gate array, thereby adjusting the two voltage-controlled phase shifters to achieve signal phase regulation; the analog-to-digital converter (AD) is connected to the field programmable gate array and the detector to collect the detection voltage output by the detector under the control of the field programmable gate array, and transmit the detection voltage to the field programmable gate array after analog-to-digital conversion to determine the detection voltage corresponding to the minimum output signal power, thereby finding the optimal bias voltage to achieve adaptive interference suppression.

[0047] Further preferably, a field programmable gate array (FPGA) controls a digital-to-analog converter (DA) to output the bias voltage V1 according to different step values ​​(for example: outputting from 0 to the maximum output voltage of the FPGA in a minimum step, and the specific minimum step value is determined by the number of bits of each FPGA and the maximum output voltage), and sets a corresponding clock according to the response time of the dual-channel module and the conversion time of the analog-to-digital converter (AD) to control the reading of the detection voltage V2, and make the bias voltage V1 correspond one-to-one with the corresponding detection voltage V2 after phase shifting, and by comparing the size of V2, continuously output the bias voltage V1 that minimizes the amplitude of the detection signal.

[0048] In one embodiment, it also includes: a conditioning module, that is, the RF front-end circuit includes: a dual-channel module, a control module and a conditioning module; the conditioning module is arranged between the control module and the voltage-controlled phase shifter to linearly adjust the range of the bias voltage output by the control module to the bias voltage range required by the voltage-controlled phase shifter, and provide power for active devices such as the low-noise amplifier in the dual-channel module.

[0049] Preferably, the conditioning module includes: a power supply part and a conditioning part; the power supply part provides power for the active circuit part, specifically, a linear regulator is used to convert the power supply voltage into a rated output voltage and then output it stably through a capacitor; the conditioning part linearly amplifies the input voltage from 0 to 5V to 0 to 14V, specifically, two operational amplifier chips are used to linearly amplify the input voltage in the range of 0 to 5V to an output voltage in the range of 0 to 14V. It should be noted that the specific linear regulator, capacitor, and operational amplifier chip in the conditioning module are all prior art.

[0050] In one embodiment, the dual-channel module also includes: a low-noise amplifier, that is, the dual-channel module includes: a voltage-controlled phase shifter, a power combiner, a coupler, a detector and a low-noise amplifier; the low-noise amplifier is arranged between the output port and the coupler to compensate for insertion loss and reduce the attenuation of the desired signal.

[0051] In one embodiment, the dual-channel module also includes: an adjustable low-noise amplifier, that is, the dual-channel module includes: a voltage-controlled phase shifter, a power combiner, a coupler, an adjustable low-noise amplifier, a detector and a low-noise amplifier; the adjustable low-noise amplifier is arranged between the detector and the coupler to ensure that the power of the signal is within the working range of the detector.

[0052] Preferably, the adjustable low noise amplifier comprises: two low noise amplifiers and an attenuator; the collector and emitter of one low noise amplifier are connected to the coupler, and the base is connected to one end of the attenuator; the collector and emitter of the other low noise amplifier are connected to the other end of the attenuator, and the base is connected to the detector.

[0053] Further preferably, the attenuation value of the attenuator is adjustable, so that the gain of the adjustable low noise amplifier can be adjusted by adjusting the attenuation value of the attenuator. Specifically, when the interference signal strength is too large, the gain of the low noise amplifier to the coupled signal is reduced by increasing the attenuation multiple of the attenuator, and when the interference signal strength is small, the gain of the low noise amplifier to the coupled signal is increased by reducing the attenuation multiple of the attenuator, so that the interference strength is within the detection power range of the detector.

[0054] It should be noted that the specific structures of the voltage-controlled phase shifter, power combiner, coupler, detector, low-noise amplifier, attenuator, field programmable gate array, digital-to-analog converter and analog-to-digital converter in this application are all prior arts.

[0055] like Figure 3 and Figure 4 As shown, in this application, the whole process is regarded as a negative feedback loop: the FPGA outputs a finite number (for example, 2 8 8 is the number of bits of FPGA) bias voltage V1 to control the phase shift of voltage-controlled phase shifter; the amplitude of the synthesized signal after phase shift is detected by the detector, and the corresponding detection voltage V2 is output; the detection voltage V2 is read by FPGA through AD, and by comparing the V2 values ​​collected under different V1 controls, the V1 that can minimize the amplitude of the detection signal is found, and the optimal V1 is continuously output to achieve adaptive interference suppression.

[0056] The above-mentioned adaptive amplitude-phase weighted RF front-end circuit adopts the idea of ​​dual-channel interference anti-phase synthesis cancellation, and uses FPGA to compare the amplitude of the cancellation synthesis output signal under different phase weightings to give the optimal phase weight, thereby realizing adaptive amplitude-phase weighted interference suppression, and can cope with high-power suppressive strong electromagnetic saturation interference, and has the ability to adaptively suppress unknown suppressive strong electromagnetic interference; a low-noise amplifier is used to compensate for the link loss of the signal, and it has the characteristic of no insertion loss; in addition, the combination of the detector and FPGA is adopted, and the adaptive interference suppression function does not depend on the specific interference frequency point, and it also has the advantages of adaptability, large interference power suppression, wide working bandwidth, simple circuit structure, miniaturization, low cost, etc., and has broad application prospects in the RF front end.

[0057] In a specific embodiment, an adaptive amplitude and phase weighted radio frequency front-end circuit is experimentally tested.

[0058] like Figure 5As shown, S21 of the circuit of the present application is above 0dB within 2GHz-4GHz, indicating that the circuit has no insertion loss within 2GHz-4GHz, S11 and S22 are below -10dB, and the operating bandwidth of the circuit is 2GHz-4GHz, indicating that the circuit has the characteristics of wide operating bandwidth and no insertion loss, and S12 is below -35dB, indicating that the reverse transmission from the output end to the input end of the circuit is almost negligible, the isolation performance of the device is good, and the circuit stability is high.

[0059] like Figure 6 As shown, the circuit of the present application is installed at the feeder end of the binary array antenna, and the transmitting end transmits a single-frequency continuous wave interference signal with a frequency of 2GHz-4GHz and a single-frequency continuous wave desired signal with a frequency of 3GHz at a random incidence angle. One curve is the interference suppression capability for interferences of different frequencies when the desired signal is 3GHz, and the other curve is the signal loss under interferences of different frequencies when the desired signal is 3GHz. It can be seen that when the frequency of the desired signal is 3GHz and the frequency of the interference signal changes within the working bandwidth, the signal loss (referring to the loss of the desired signal while suppressing the interference signal) is a negative value, that is, the circuit has a signal enhancement effect on the desired signal, and the enhancement effect is between 5dB-10dB, and has a suppressive effect on interferences of different frequencies within 2GHz-4GHz, with a maximum suppression capability of 34.47dB, indicating that the circuit of the present application has adaptive interference suppression capability, and compared with the adaptive suppression interference suppression technology for unknown suppression interference in the prior art with a suppression capability of less than 25dB, the present application has great advantages.

[0060] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0061] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A radio frequency front-end circuit with adaptive amplitude and phase weighting, characterized in that: Including connected: dual channel module and control module; The dual-channel module includes: a voltage-controlled phase shifter, a power combiner, a coupler, and a detector connected in sequence; the number of the voltage-controlled phase shifters is two, one corresponding end of the two voltage-controlled phase shifters is respectively connected to the two input ports of the radio frequency front end, and the other corresponding end is connected to the coupler through the power combiner, so as to divide the circuit passing through the coupler into two channels, one channel is connected to the output port of the radio frequency front end, and the other channel is connected to the detector to output the detection voltage of the detection signal; The control module outputs a bias voltage, performs phase shift control on two voltage-controlled phase shifters, and obtains a corresponding detection voltage as a current detection voltage; compares the current detection voltage with the previous detection voltage, obtains an optimal detection voltage that makes the amplitude of the detection signal smaller, and outputs a corresponding bias voltage in real time to achieve adaptive amplitude-phase weighting.

2. The RF front-end circuit with adaptive amplitude and phase weighting according to claim 1, characterized in that: The control module includes: a field programmable gate array, a digital-to-analog converter and an analog-to-digital converter; The digital-to-analog converter is connected to the field programmable gate array and the voltage-controlled phase shifter to output a bias voltage to adjust the two voltage-controlled phase shifters under the control of the field programmable gate array; The analog-to-digital converter is connected to the field programmable gate array and the detector to collect the detection voltage output by the detector under the control of the field programmable gate array.

3. The RF front-end circuit with adaptive amplitude and phase weighting according to claim 2, characterized in that: The field programmable gate array controls the digital-to-analog converter to output the bias voltage according to different step values, and sets the corresponding clock according to the response time of the dual-channel module and the conversion time of the analog-to-digital converter, so that the bias voltage corresponds one-to-one with the corresponding detection voltage after phase shifting.

4. The RF front-end circuit with adaptive amplitude and phase weighting according to any one of claims 1 to 3, characterized in that: Also includes: A conditioning module is provided between the control module and the voltage-controlled phase shifter to linearly regulate the range of the bias voltage to the voltage range required by the voltage-controlled phase shifter.

5. The RF front-end circuit with adaptive amplitude and phase weighting according to claim 4, characterized in that: The conditioning module comprises: a power supply part and a conditioning part; The power supply part provides power for the active circuit part, and the conditioning part linearly amplifies the input voltage from 0 to 5V to 0 to 14V.

6. The RF front-end circuit with adaptive amplitude and phase weighting according to any one of claims 1 to 3, characterized in that: The dual-channel module further comprises: a low noise amplifier arranged between the output port and the coupler to compensate for insertion loss and reduce attenuation of the desired signal.

7. The RF front-end circuit with adaptive amplitude and phase weighting according to any one of claims 1 to 3, characterized in that: The dual-channel module further comprises: an adjustable low-noise amplifier arranged between the detector and the coupler to ensure that the power of the signal is within the working range of the detector.

8. The RF front-end circuit with adaptive amplitude and phase weighting according to claim 7, characterized in that: The adjustable low noise amplifier comprises: two low noise amplifiers and an attenuator; A low noise amplifier has a collector and an emitter connected to the coupler, and a base connected to one end of the attenuator; The collector and emitter of another low noise amplifier are both connected to the other end of the attenuator, and the base is connected to the detector.

9. The RF front-end circuit with adaptive amplitude and phase weighting according to claim 8, characterized in that: The attenuation value of the attenuator is adjustable, so that the amplification factor of the adjustable low noise amplifier can be adjusted by adjusting the attenuation value of the attenuator.

Images