An online fault monitoring method for a digital phased array transceiver channel

Abstract

The present invention provides an on-line fault detection method for a digital phased array transceiver channel. During transmission, the transceiver coupling effect of the RF duplexer is utilized to realize the acquisition of the coupled signal of the transmitted pulse by the receiving channel, calculate its power, and compare it with the stored threshold to determine whether the current transceiver channel state is abnormal. On this basis, further by controlling the state-abnormal channel to transmit orthogonal pulses, and utilizing the transceiver coupling effect between antenna elements and the RF duplexer, a certain adjacent antenna element with a normal channel state obtains the coupled signal of the orthogonal pulse in the receiving channel, analyzes the power of the orthogonal coupled signal and compares it with the corresponding threshold, so as to discriminate the receiving or transmitting fault of the state-abnormal channel. It is realized on-line and can be used for the evaluation of the executability of subsequent tasks of the phased array, avoiding the use of additional dedicated signal generation circuits and corresponding control circuits for fault detection, reducing the design complexity of the antenna array surface, and improving the design integration and reliability of the antenna array surface.

Description

Technical Field

[0001] The present invention relates to the technical field of digital phased arrays, and more particularly to an online fault monitoring method for digital phased array receiving channels. Background Art

[0002] The transceiver channel is the basis for constructing the digital phased array antenna array surface and is the core component of the digital phased array. The number of transceiver channels in the phased array ranges from dozens to hundreds, or even thousands to tens of thousands. Its performance, reliability and other indicators directly affect the system performance of the digital phased array. For the method of transceiver channel fault monitoring, one is to add a dedicated monitoring circuit to monitor each channel online without affecting the normal operation of the phased array device. For example, in patents CN107219509A and CN108196233A, by adding a small number of devices and using the minimum detection distance time slot of the radar system, the online status detection and fault reporting of the receiver branch parameters and the transmitter channel parameters are completed. CN110286361A uses the fixed target echo signal-to-noise ratio measurement to construct a reference model for comparison to monitor the health status of its transmitter in real time. The other is to use the original circuit or add a dedicated monitoring circuit to work in the dedicated health detection mode of the device. For example, patent CN109547050A realizes the calibration compensation and fault detection of the receive and transmit channels by adding a calibration circuit. Patent CN1845625A establishes a connection path between the fault link and the monitoring (normal) link by adding a radio frequency switch circuit in the transceiver module to perform fault judgment and realize the online monitoring of the radio frequency front-end module in the base station.

[0003] In the multi-functional application of phased array devices, the receiving channel and the transmitting channel are independent of each other. In the case of existing or occasional channel failures, it is necessary to evaluate in real time whether the entire phased array surface can continue to meet the current task requirements. Adding a dedicated circuit reduces the reliability of the entire antenna array surface and the device. How to realize the real-time online monitoring of the fault status of the transceiver channel without adding a dedicated monitoring circuit is a design problem. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides an online fault monitoring method for the transceiver channel of a digital phased array. The present invention does not add additional signal generation and testing circuits, but utilizes the coupling effect of the radio frequency duplexer between the receiving channel and the transmitting channel, as well as the coupling effect between antenna units, to realize the coupling signal collection and power calculation of the receiving channel to the transmitting pulse during transmission, and compares it with the stored threshold value to determine whether the current transceiver channel is in an abnormal state. On this basis, the orthogonal pulses are further transmitted through the abnormal state channel by controlling the coupling effect between a certain adjacent antenna unit and the transceiver shared switch in a normal channel state to obtain the coupling power of the receiving channel to the orthogonal pulse and compare it with the corresponding threshold value, so as to distinguish the reception or transmission fault of the abnormal channel, which can be realized online and can be used for the evaluation of the executable degree of the subsequent tasks of the phased array, avoiding the use of additional fault detection dedicated signal generation circuits and corresponding control circuits, reducing the complexity of the antenna array design, and improving the reliability of the antenna array.

[0005] To achieve the above-mentioned purpose, the present invention is implemented by the following scheme: the digital phased array transceiver channels are all digital, the RF end of each receiving channel and transmitting channel is connected to an antenna unit through a RF duplexer, and the digital end is connected to a programmable digital signal processor, and the transmission and receiving functions of a certain modulation frequency are realized in a time-sharing manner under the control of the wave control instruction and the transceiver control pulse: when transmitting, the RF duplexer is controlled to connect the transmitting channel and the antenna unit, and the transmitting channel generates a pulse signal, which is processed and radiated to the space through the RF duplexer to the antenna unit, and part of the energy is coupled into the receiving channel through the duplexer and digitized; when receiving, the RF duplexer is controlled to disconnect from the transmitting channel and connect to the receiving channel, and the external microwave signal enters the receiving channel through the antenna unit and the RF duplexer, and is processed and digitized by the receiving channel. The programmable digital signal processor collects the signal regularly, and sends it to the DBF module after processing; wherein the online fault monitoring method comprises the following steps:

[0006] 1) During the transmission process, part of the energy of the transmitted pulse signal X is coupled to the receiving channel through the duplexer. After linear processing and digitization by the receiving channel, it is collected regularly by the programmable digital signal processor to obtain the coupled signal power monitoring result A i , i = 1 ~ N, i is the corresponding transceiver channel and antenna unit number, the result is sent to the DBF module and compared with the corresponding frequency and the intra-unit coupling power threshold of the corresponding antenna unit. If it is within the error range, it is considered that the state of the transmitting channel and receiving channel connected to the antenna unit is normal, otherwise it is considered that the state of the transmitting channel or receiving channel connected to the current antenna unit is abnormal;

[0007] 2) When the channel status of a certain antenna unit n is detected to be abnormal and the channel status of its neighboring antenna units is not all abnormal, during the pulse transmission period of the next transceiver control cycle, the corresponding programmable digital signal processor controls the transmission channel of antenna unit n to generate a pulse signal Y orthogonal to the current transmission pulse X during the pulse signal, which is radiated by this antenna unit and enters the corresponding receiving channel through the coupling between antenna units and the transceiver coupling of the RF duplexer. Select a neighboring antenna unit n with normal channel status j And detect the signal Y through its receiving channel. After linear processing and digitization of the receiving channel, perform correlation detection on the coupled signal of Y. The detected power result is sent to the DBF module to be compared with the coupling power threshold between the corresponding neighboring units. If it is within the error range, it is determined that the transmission channel status of the antenna unit n is normal and the receiving channel status is abnormal. If there is an out-of-tolerance situation, it is determined that the transmission channel status of the antenna unit n is abnormal and the receiving channel status is normal.

[0008] The linear processing refers to calculating the attenuation control parameters of the receiving channel according to the transmission power, transceiver isolation of the RF duplexer, isolation between units, input 1dB compression point of the receiving channel, ADC input 1dB compression point, and linear dynamic range of the receiving channel. During the monitoring enabled transmission period, control the attenuator to make all receiving channels in the linear working area, and perform linear processing on the coupled signal to be detected, including but not limited to RF filtering, attenuation, amplification, frequency conversion, and intermediate frequency filtering functions: Calculation of the transceiver coupling power within the antenna unit

[0009] The power value P0 of the coupled signal within the antenna unit at the receiver input port needs to meet the requirement of being less than the -1dB compression point of the receiving channel saturation signal, as shown in the following formula:

[0010] P0 = Pt - D1 < P -1R ;

[0011] In order to make the receiving channel in the linear working area, set the attenuation ΔL of the receiving channel attenuator. After the coupled signal is processed by the receiving, the power value P1 of the coupled signal within the antenna unit at the ADC input port needs to meet the requirement of being in the linear working range of the receiver, as shown in the following formula:

[0012]

[0013] Calculation of the coupling power between neighboring antenna units

[0014] The power value P of the coupled signal between neighboring antenna units at the receiver input port ij 0 needs to meet the requirement of being less than the -1dB compression point of the receiving channel saturation signal, as shown in the following formula:

[0015] P ij 0 = Pt - D2 - D1 < P -1R ;

[0016] P ij 1 Calculation:

[0017] In order to make the receiving channel in the linear working area, the receiving channel attenuator is set to attenuate ΔL. After the coupled signal is received and processed, the power value P of the coupled signal between the adjacent antenna units at the ADC input port is ij 1 and the coupled signal power value P1 in the antenna unit at the ADC input port must meet the requirement of being in the linear working range of the receiver, as shown in the following formula:

[0018]

[0019] Pt is the peak power value of the transmission channel; P0 is the coupled signal power value of the receiver input port in the antenna unit; P ij 0 is the coupled signal power value of the receiver input port in the adjacent antenna unit; G is the receiving channel gain; D1 is the isolation from the duplexer transmitting channel to the receiving channel; D2 is the isolation between adjacent antenna units; L is the maximum attenuation of the attenuator; P -1AD ADC input 1dB compression point; P -1R is the 1dB compression point of the receiving channel input; SFDR is the linear dynamic range of the receiving channel.

[0020] The intra-cell coupling power threshold table in the DBF module and the inter-adjacent-cell coupling power threshold are obtained by the following steps:

[0021] 1) The digital array completes the channel amplitude and phase calibration of the entire working frequency band in the microwave darkroom, and all the transmitting and receiving channels are in normal status;

[0022] 2) Select an operating frequency. Under the control of the transceiver control pulse, all transmitting channels generate a minimum pulse width Tmin pulse X and transmit at full power. The attenuator control parameter of the receiving channel is calculated according to the transceiver isolation of the RF duplexer. During the transmission, the attenuator is controlled so that all receiving channels are in the linear working area. The transmission coupling signal obtained by the transceiver coupling of the RF duplexer of the transceiver channel is linearly processed and digitized by the receiving channel, and then collected regularly by the programmable digital signal processor to obtain the coupling signal power monitoring result A. i0 , i = 1 to N, i is the corresponding transceiver channel number, and is recorded as the intra-unit coupling power threshold of the frequency antenna unit i;

[0023] 3) All transceiver channels control their transmit channels in turn to generate a pulse signal Y with a pulse width of Tmin and orthogonal to X, and the remaining transmit channels generate pulses X with a pulse width of Tmin. All channels transmit at full power. After pulse Y is radiated into space through antenna unit i, it is coupled into the adjacent unit of antenna unit i (connected to transceiver channel i) and coupled into its receiving channel through its transceiver switch. The coupled signal of Y is linearly processed and digitized by the receiving channel and then collected regularly by a programmable digital signal processor to obtain the coupled signal power monitoring result Cij, i=1~N, j≤8, and recorded as the coupling power threshold between adjacent units of antenna unit i at this frequency;

[0024] 4) The entire operating frequency is traversed in sequence to form an intra-unit coupling power threshold table and an inter-adjacent unit coupling power threshold table, and stored in the DBF module.

[0025] Preferably, the transmit pulse width Tmin≥256 / fs, where fs is the ADC sampling rate of the receiving channel.

[0026] Preferably, the neighboring antenna units of a certain antenna unit refer to a circle of antenna units that are closest to the array spacing of the antenna unit.

[0027] Preferably, the digital transceiver channels are independent of each other, and the RF end has only one RF duplexer transceiver switch (single pole double throw) connected to the RF input and output port of the shared antenna unit.

[0028] Preferably, the linear processing refers to calculating the attenuator control parameters of the receiving channel according to the transmission power, the transceiver isolation of the RF duplexer, the isolation between units, the input 1dB compression point of the receiving channel, the input 1dB compression point of the ADC, and the linear dynamic range of the receiving channel. During the monitoring enabling transmission period, the attenuator is controlled so that all receiving channels are in the linear working area, and the coupled signal to be detected is subjected to linear processing including but not limited to RF filtering, attenuation, amplification, frequency conversion, and intermediate frequency filtering functions:

[0029] Calculation of transmit and receive coupling power within the antenna unit:

[0030] The coupled signal power value P0 in the antenna unit at the receiver input port must meet the requirement of being less than the -1dB compression point of the saturation signal of the receiving channel, as shown in the following formula:

[0031] P0=Pt-D1<P -1R ;

[0032] In order to make the receiving channel in the linear working area, the receiving channel attenuator is set to attenuate ΔL. After the coupled signal is received and processed, the coupled signal power value P1 in the antenna unit of the ADC input port must meet the requirement of being in the linear working range of the receiver, as shown in the following formula:

[0033]

[0034] Calculation of the coupling power between adjacent antenna elements:

[0035] The coupling signal power value P ij 0 between adjacent antenna elements at the receiver input port needs to meet the requirement of being less than the -1 dB compression point of the saturation signal of the receiving channel, as shown in the following formula:

[0036] P ij 0 = Pt - D2 - D1 < P -1R ;

[0037] P ij 1 calculation:

[0038] In order to make the receiving channel operate in the linear working area, set the attenuation ΔL of the receiving channel attenuator. After the coupling signal is processed by the receiver, the power value P ij 1 of the coupling signal between adjacent antenna elements at the ADC input port and the power value P1 of the in-antenna-element coupling signal at the ADC input port both need to meet the requirement of being within the linear working range of the receiver, as shown in the following formula:

[0039]

[0040] Pt is the peak power value of the transmitting channel; P0 is the coupling signal power value at the receiver input port within the antenna element; P ij 0 is the coupling signal power value at the receiver input port between adjacent antenna elements; G is the gain of the receiving channel; D1 is the isolation between the transmitting channel and the receiving channel of the duplexer; D2 is the isolation between adjacent antenna elements; L is the maximum attenuation of the attenuator; P -1AD is the 1 dB compression point of the ADC input; P -1R is the 1 dB compression point of the receiving channel input; SFDR is the linear dynamic range of the receiving channel.

[0041] Preferably, the RF duplexer includes but is not limited to a transceiver switch or a circulator and their combinations.

[0042] Compared with the prior art, the present invention has the following advantages:

[0043] 1. Based on the inherent coupling effect between the RF duplexer and the antenna elements, use the coupling signal of the receiving channel of the transmitted pulse to judge the abnormal state of the transmitting channel and the receiving channel. Further, use the received coupling signal of the transmitted orthogonal pulse to judge the faults of the transmitting channel and the receiving channel. The dedicated signal generation circuit and the corresponding control circuit for fault detection are reduced in the transmitting and receiving channels and the antenna array surface, realizing real-time online monitoring of the fault states of the transmitting and receiving channels, reducing the design complexity of the antenna array surface, and improving the design integration and reliability of the antenna array surface.

[0044] 2 The implementation of real-time online monitoring of the fault status of the transceiver channel can reduce the fault detection time of the entire phased array dedicated channel, and can provide real-time evaluation of the performance degradation of subsequent tasks, thereby improving the testability of the system and the task execution efficiency of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of the layout of the array antenna units in Example 1;

[0046] Figure 2 Digital transceiver channel composition principle block diagram module;

[0047] Figure 3 Flowchart of detection threshold acquisition steps;

[0048] Figure 4 Flowchart of transceiver channel fault detection. DETAILED DESCRIPTION

[0049] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] Example 1

[0051] In this example, the array antenna unit layout is as follows Figure 1 As shown in the figure: the digital array antenna plane is an 8*8 unit array, and the serial numbers of the antenna units are arranged from top to bottom and from left to right. The first column on the left is An1, An2, ...An8, the second column on the left is An9, An10, ...An16, ... the eighth column on the left is An57, An58, ...An64, and the adjacent antenna unit of an antenna unit Ani refers to the antenna unit in the circle closest to its array spacing. The adjacent antenna units of antenna unit An1 are An2, An9, An1 0, the adjacent antenna units of antenna unit An8 are An7, An15, and An16, the adjacent antenna units of antenna unit An57 are An49, An50, and An58, the adjacent antenna units of antenna unit An64 are An55, An56, and An63, the adjacent antenna units of antenna unit An2 are An1, An3, An9, An10, and An11, the adjacent antenna units of antenna unit An3 are An2, An4, An10, An11, and An12, and so on. The 8*8 antenna array unit is connected to 8*8 identical digital transmission channels and the same number of digital receiving channels. Every 8 circuits form the same digital transceiver channel. In physical form, it forms a subarray transceiver module, with a total of 8 modules, and each transceiver channel shares an antenna unit. The block diagram of the transceiver channel is as follows: Figure 3As shown, each receiving channel has an independent amplifier, frequency converter, gain control attenuator, filter, and ADC. Each transmitting channel has an independent DAC, filter, frequency converter, power amplifier, and power detection module. Each transceiver channel is connected to the corresponding antenna unit through a high-power switch. The DAC and other control and detection signals of the transceiver channel are all connected to the programmable signal processor FPGA of the same subarray transceiver module. Among them, the ADC selects the AD9230 of ADI Corporation (fs = 250 MHz). The peak power value of the transmitting channel Pt = 30 dBm; the isolation degree D1 from the transmitting channel to the receiving channel of the duplexer = 70 dB; the isolation degree between adjacent antenna units is 20 dB to 40 dB; the gain G of the receiving channel = 50 dB; the saturation signal -1 dB compression point of the receiving channel is P -1R =-25 dBm, and the saturation signal -1 dB compression point of the ADC input is P -1AD =6 dBm. The linear dynamic range SFDR of the receiving channel is 48 dB. The controllable range of the gain control attenuator of the receiving channel is L = 30 dB. The transceiver coupling power within the antenna unit and the coupling power between adjacent units both meet the requirements of the linear working range of the receiving channel. Calculate it and obtain the control amount of the interface channel attenuator:

[0052] Calculation of the power value P0 of the coupling signal within the antenna unit at the receiver input port:

[0053] P0 = Pt - D1 = 30 - 70 = -40 dBm < P -1R =-25 dBm. The coupling signal power at the receiver input port does not exceed the saturation signal -1 dB compression point of the receiving channel;

[0054] Calculation of the power value P1 of the coupling signal within the antenna unit at the ADC input port:

[0055] P1 = Pt - D1 + G = 30 - 70 + 50 = 10 dBm > P -1AD

[0056] It has exceeded the ADC input saturation -1 dB compression point. In order to make the receiving channel in the linear working area, set the attenuation of the receiving channel attenuator ΔL = 10 dB. The power P1 of the coupling signal reaching the ADC entrance after amplification is:

[0057] P1 = Pt - D1 + G - ΔL = 30 - 70 + 50 - 10 = 0 dBm < P -1AD =6 dBm,

[0058] P1 = Pt - D1 + G - ΔL = 0 dBm > P -1AD -SFDR = 6 - 48 = -42 dBm

[0059] Meet the requirements of the receiver linear working range;

[0060] The power value P of the coupling signal between adjacent units at the receiver input port ij 0 calculation:

[0061] P ij 0 = Pt - D2 - D1 = 30 - 20 - 70 = -60dBm < P -1R = -25dBm

[0062] The coupling signal power at the receiver input port does not exceed the -1dB compression point of the receive channel saturation signal;

[0063] The power value P of the coupling signal between adjacent units at the ADC input port ij 1 calculation:

[0064] P ij 1 = Pt - D2 - D1 + G = 30 - 20 - 70 + 50 = -10dBm < P -1AD

[0065] It does not reach the ADC input saturation -1dB compression point, but the transmit - receive coupling power P1 = 10dBm at the ADC input port within this antenna unit has exceeded the ADC input saturation -1dB compression point. To make the receive channel operate in the linear working region, set the attenuation ΔL of the receive channel attenuator to 10dB. The power P of the coupling signal after amplification and reaching the ADC entrance is ij 1 is:

[0066] P ij 1 = Pt - D2 - D1 + G - ΔL = 30 - 20 - 70 + 50 - 10 = -20dBm < P -1AD = 6dBm,

[0067] P ij 1 = Pt - D2 - D1 + G - ΔL = -20dBm > P -1AD -SFDR = 6 - 48 = -42dBm

[0068] P1, P ij 1 both meet the requirements of the receiver linear working range; The calculation of the transmit pulse width ≥ Tmin = 256 / fs = 256 * 4ns = 1024ns.

[0069] First, obtain the coupling power threshold table within the unit and the coupling power threshold table between adjacent units:

[0070] 1) The digital array completes the channel amplitude - phase calibration of the entire working frequency band in the microwave anechoic chamber, and all transmit - receive channel states are normal;

[0071] 2) Select a working frequency F0. Under the control of the transceiver control pulse, all the transmitting channels generate a pulse X with a pulse width of 1024 ns and transmit at full power. During the transmission, the attenuator attenuation of the receiving channels is controlled to be 10 dB to make all the receiving channels in the linear working region. The transmitted coupling signal obtained by the transceiver coupling of the high-power transceiver channels passes through the linear processing and digitization of the receiving channels and is then periodically collected by the programmable digital signal processor to obtain the coupling signal power monitoring result A. i0 , i = 1 to N, where i is the corresponding transceiver channel number, and record it as the in-unit coupling power threshold of the antenna element i at this frequency;

[0072] 3) All the transceiver channels sequentially control their transmitting channels to generate a pulse signal Y with a pulse width of 1024 ns and orthogonal to X, and the remaining transmitting channels generate a pulse X with a pulse width of 1024 ns. All the channels transmit at full power. During the transmission, the attenuator attenuation is controlled to be 10 dB to make all the receiving channels in the linear working region. After the pulse Y is radiated into space through the antenna element Ani, it is coupled into the adjacent element of the antenna element Ani (connected to the transceiver channel i) and enters its receiving channel through its transceiver switch. The coupling signal of Y passes through the linear processing and digitization of the receiving channel and is then periodically collected by the programmable digital signal processor to conduct relevant detections to obtain the coupling signal power monitoring result Cij, i = 1 to N, j ≤ 8, and record it as the inter-adjacent-element coupling power threshold of the antenna element i at this frequency;

[0073] 4) Sequentially traverse the entire working frequency to form an in-unit coupling power threshold table and an inter-adjacent-element coupling power threshold table, and store them in the DBF module.

[0074] When the phased array is working, the 8 sub-array transceiver modules on the antenna array surface enter the transmitting state under the control of the beam control instruction and the transceiver control (trigger) pulse. The sub-array transceiver module processes the digital baseband pulse signal with a pulse width of τ seconds generated by the internal FPGA through digital-to-analog conversion, filtering, frequency conversion, amplification, etc. and then radiates it into space through the antenna element.

[0075] During the transmission process, part of the energy of the transmitted pulse signal is coupled to the receiving channel through the transceiver switch. The attenuator attenuation is controlled to be 10 dB to make all the receiving channels in the linear working region. After passing through filtering, attenuation, amplification, frequency conversion, intermediate-frequency filtering, and digitization of the receiving channel, it is periodically collected by the programmable digital signal processor to obtain the coupling signal power monitoring result A. i , i = 1 to N, where i is the corresponding transceiver channel and antenna element number. After this result is sent to the DBF module, it is compared with the in-unit coupling power threshold of the corresponding frequency and corresponding antenna element stored. If it is within the 2 dB error range, it is considered that the transmitting channel and receiving channel of this antenna element are in normal state; otherwise, it is considered that there is an abnormality in the transmitting channel or receiving channel of the current antenna element.

[0076] Furthermore, when it is detected that the channel state of a certain antenna unit An is abnormal and the channel states of its neighboring antenna units are normal, the antenna unit An is controlled by the corresponding programmable digital signal processor during the pulse emission period of the next transceiver control cycle. i During the pulse signal generation of the transmitting channel of An, a short pulse signal with a pulse width of 1024 ns orthogonal to the current transmission pulse is generated. A neighboring antenna unit An with a normal channel state is selected. i The coupled signal is received and processed. After digitization, correlation detection is performed on the inserted orthogonal short pulse. The power of the detection result is compared with the corresponding threshold. If it is within a 2 dB error range, it is considered that the transmitting channel is normal and the receiving channel is abnormal. If an out-of-tolerance situation occurs, it is determined that the transmitting channel is abnormal and the receiving channel is normal. ij

[0077] The above embodiments are only used to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the present invention.​

Claims

1. An online fault monitoring method for a digital phased array transceiver channel, characterized in that: The digital phased array transceiver channels are all digital. The RF end of each receiving channel and transmitting channel is connected to an antenna unit through a RF duplexer, and the digital end is connected to a programmable digital signal processor. The transmission and receiving functions of a certain modulation frequency are realized in a time-sharing manner under the control of the wave control instruction and the transceiver control pulse: when transmitting, the RF duplexer is controlled to connect the transmitting channel and the antenna unit, and the pulse signal generated by the transmitting channel is processed and radiated to the space through the RF duplexer to the antenna unit, and part of the energy is coupled into the receiving channel through the duplexer and digitized; when receiving, the RF duplexer is controlled to disconnect from the transmitting channel and connect to the receiving channel, and the external microwave signal enters the receiving channel through the antenna unit and the RF duplexer, and is processed and digitized by the receiving channel. The programmable digital signal processor collects the received signal at a fixed time, and sends it to the DBF module after processing; the online fault monitoring method comprises the following steps: 1) During the transmission process, part of the energy of the transmitted pulse signal X is coupled to the receiving channel through the duplexer. After being linearly processed and digitized by the receiving channel, it is periodically collected by the programmable digital signal processor to obtain the monitoring result A of the coupled signal power. i , where i is the corresponding transceiver channel and antenna unit serial number, i = 1 to N. This result is sent to the DBF module to be compared with the in-unit coupling power threshold of the corresponding frequency and corresponding antenna unit. If it is within the error range, the states of the transmitting channel and the receiving channel connected to this antenna unit are considered normal; otherwise, the state of the transmitting channel or the receiving channel connected to the current antenna unit is considered abnormal. 2) When the channel status of a certain antenna unit n is detected to be abnormal and the channel status of its adjacent antenna units is not all abnormal, during the pulse emission period of the next transceiver control cycle, the transmitting channel of antenna unit n is controlled by the corresponding programmable digital signal processor to generate a pulse signal Y orthogonal to the current transmission pulse X during the pulse signal, which is radiated by this antenna unit and enters the corresponding receiving channel through the coupling between antenna units and the transceiver coupling of the RF duplexer. Select an adjacent antenna unit n with normal channel status j And detect the signal Y through its receiving channel. After linear processing and digitization of the receiving channel, perform correlation detection on the coupled signal of Y. The detected power result is sent to the DBF module for comparison with the coupling power threshold between the corresponding adjacent units. If it is within the error range, it is determined that the transmitting channel status of antenna unit n is normal and the receiving channel status is abnormal. If there is an out-of-tolerance situation, it is determined that the transmitting channel status of antenna unit n is abnormal and the receiving channel status is normal; The linear processing refers to calculating the attenuator control parameters of the receiving channel according to the transmission power, the RF duplexer transceiver isolation, the isolation between units, the receiving channel input 1dB compression point, the ADC input 1dB compression point, and the linear dynamic range of the receiving channel. During the monitoring enabled transmission period, the attenuator is controlled so that all receiving channels are in the linear working area, and the coupled signal to be detected is subjected to linear processing including but not limited to RF filtering, attenuation, amplification, frequency conversion, and intermediate frequency filtering functions: Calculation of the transmit-receive coupling power in the antenna unit: The coupling signal power value P0 in the antenna unit at the receiver input port must meet the requirement of being less than the -1dB compression point of the saturation signal of the receiving channel, as shown in the following formula: P0 = Pt - D1 < P -1R ; In order to make the receiving channel in the linear working area, the receiving channel attenuator is set to attenuate ΔL. After the coupled signal is received and processed, the coupled signal power value P1 in the antenna unit of the ADC input port must meet the requirement of being in the linear working range of the receiver, as shown in the following formula: Calculation of the coupled power between adjacent antenna elements. The power value P of the coupled signal between adjacent antenna elements at the input of the receiver ij 0 shall meet the requirement of being less than the -1dB compression point of the saturation signal of the receiving channel, as shown in the following formula: P ij 0 = Pt - D2 - D1 < P -1R ; P ij 1 Calculation: To make the receiving channel operate in the linear working region, set the attenuation ΔL of the receiving channel attenuator. After the coupled signal is processed by reception, the power value P of the coupled signal between adjacent antenna elements at the ADC input port and the power value P1 of the coupled signal within the antenna element at the ADC input port both need to meet the requirements of being within the linear working range of the receiver, as shown in the following formula: ij 1 and the power value P1 of the coupled signal within the antenna element at the ADC input port both need to meet the requirements of being within the linear working range of the receiver, as shown in the following formula: Pt is the peak power value of the transmitting channel; P0 is the power value of the coupled signal at the input port of the receiver within the antenna element; P ij 0 is the power value of the coupled signal at the input port of the receiver within the adjacent antenna element; G is the gain of the receiving channel; D1 is the isolation from the transmitting channel to the receiving channel of the duplexer; D2 is the isolation between adjacent antenna elements; L is the maximum attenuation of the attenuator; P -1AD is the 1dB compression point of the ADC input; P -1R is the 1dB compression point of the receive channel input; SFDR is the linear dynamic range of the receiving channel.

2. The on-line fault monitoring method for a digital phased array transceiver channel according to claim 1, characterized in that: The intra-cell coupling power threshold table in the DBF module and the inter-adjacent-cell coupling power threshold are obtained by the following steps: 1) The digital array completes the channel amplitude and phase calibration of the entire working frequency band in the microwave darkroom, and all the transmitting and receiving channels are in normal status; 2) Select an operating frequency. Under the control of the transceiver control pulse, all transmitting channels generate a minimum pulse width Tmin pulse X and transmit at full power. The attenuator control parameter of the receiving channel is calculated according to the transceiver isolation of the RF duplexer. During the transmission, the attenuator is controlled so that all receiving channels are in the linear working area. The transmission coupling signal obtained by the transceiver coupling of the RF duplexer of the transceiver channel is linearly processed and digitized by the receiving channel, and then collected regularly by the programmable digital signal processor to obtain the coupling signal power monitoring result A. i0 , i = 1 to N, i is the corresponding transceiver channel number, and is recorded as the intra-unit coupling power threshold of the frequency antenna unit i; 3) All the transmitting and receiving channels control their transmitting channels in turn to generate a pulse signal Y with a pulse width of Tmin and orthogonal to X, and the remaining transmitting channels generate pulses X with a pulse width of Tmin. All channels transmit at full power. After the pulse Y is radiated into space by the antenna unit i, it is coupled into the adjacent unit of the antenna unit i and coupled into its receiving channel through its transceiver switch. The coupling signal of Y is linearly processed and digitized by the receiving channel and then collected regularly by the programmable digital signal processor to obtain the coupling signal power monitoring result Cij, i=1~N, j≤8, and recorded as the coupling power threshold between the adjacent units of the antenna unit i at this frequency; 4) The entire operating frequency is traversed in sequence to form an intra-unit coupling power threshold table and an inter-adjacent unit coupling power threshold table, and stored in the DBF module.

3. A method for online fault monitoring of a digital phased array transceiver channel according to claim 1 or claim 2, characterized in that: The transmit pulse width Tmin≥256 / fs, where fs is the ADC sampling rate of the receiving channel.

4. A method for online fault monitoring of a digital phased array transceiver channel according to claim 1 or claim 2, characterized in that: The neighboring antenna units of a certain antenna unit refer to a circle of antenna units that are closest to the array spacing of the antenna unit.

5. A method for online fault monitoring of a digital phased array transceiver channel according to claim 1 or claim 2, characterized in that: The digital transceiver channels are independent of each other, and the radio frequency end has one and only one radio frequency duplexer connected to the radio frequency input and output port of the shared antenna unit.

6. A method for online fault monitoring of a digital phased array transceiver channel according to claim 1 or claim 2, characterized in that: The radio frequency duplexer includes but is not limited to a transceiver switch or a circulator and a combination thereof.

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