Time control array radar and built-in self-checking calibration method thereof

Abstract

The invention provides a time control array radar and a built-in self-checking calibration method thereof, and belongs to the technical field of array radar performance detection. The time control array radar comprises a self-checking calibration control module, a plurality of parallel sub-array modules and a plurality of parallel sub-array preprocessing modules, and the built-in self-checking calibration method of the time control array radar adopts the self-checking calibration control module. The time delay consistency and the amplitude consistency of each transceiving channel and each sub-array preprocessing module in a receiving / transmitting mode can be quickly and accurately detected, the self-checking calibration of each channel and module is ensured not to influence each other through the high isolation performance of the multi-stage switch, the precision and the stability of the self-checking calibration are improved, and the accuracy and the reliability of the self-checking calibration are improved. Therefore, the normal work of the time control array radar is ensured.

Description

Technical Field

[0001] This invention relates to the field of array radar performance testing technology, and in particular to a time-controlled array radar and its in-system self-test calibration method. Background Technology

[0002] Phased array radar is a type of radar capable of flexible beam control and possesses strong airspace anti-jamming capabilities. The various components within a phased array radar require amplitude and delay consistency to ensure normal beamforming and scanning. Current technologies typically use internal self-test calibration to verify the amplitude and delay consistency among the components, thus guaranteeing the normal operation of the phased array radar.

[0003] Time-controlled array radar is a new type of array radar that achieves beam scanning, shaping, and signal processing by controlling the opening and closing time of signal transmission and reception channels. Currently, there is a lack of onboard self-testing and calibration methods for time-controlled array radar, which makes it impossible to guarantee the normal operation of time-controlled array radar. Summary of the Invention

[0004] This invention proposes a time-controlled array radar and its in-flight self-test calibration method, which can realize the in-flight self-test calibration of the time-controlled array radar, thereby ensuring the normal operation of the time-controlled array radar.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a time-controlled array radar, comprising: a self-test calibration control module, multiple subarray modules arranged in parallel, and multiple subarray preprocessing modules arranged in parallel. The self-test calibration control module is used for the in-system self-test calibration of the time-controlled array radar. The self-test calibration control module includes an up / down conversion module, a switch submodule, a coupler submodule, and a signal processing submodule. The up / down conversion module includes a mixer and a first digital-to-analog converter and a first analog-to-digital converter electrically connected to the mixer. The switch submodule includes a transmit / receive self-test selection switch, a self-test location selection switch, a subarray module selection switch, a transmit / receive component selection switch, and a channel selection switch. The coupler submodule includes multiple first self-test calibration couplers and multiple second self-test calibration couplers. The signal processing submodule is used to perform self-test calibration on the subarray modules and subarray preprocessing modules. The first digital-to-analog converter and the first analog-to-digital converter are also electrically connected to the signal processing submodule. The mixer is also electrically connected to the transmit / receive self-test selection switch and the self-test location selection switch in sequence. The self-test location selection switch is electrically connected to the subarray module selection switch and the transmit / receive component selection switch, respectively. Multiple first self-test calibration couplers are electrically connected to the channel selection switch, and multiple second self-test calibration couplers are electrically connected to the subarray module selection switch. Multiple parallel subarray modules are used to receive and / or transmit ultra-wideband pulse signals. Each subarray module is electrically connected to a subarray preprocessing module. Each subarray module includes parallel combiners / splitters and multiple transceiver components. Each transceiver component includes multiple parallel transceiver channels. For each transceiver channel, one end is electrically connected to a first self-calibration coupler, and the other end is electrically connected to the combiner / splitter. The first self-calibration coupler is also electrically connected to an antenna. The parallel subarray preprocessing modules are used to process the aforementioned ultra-wideband pulse signals. Each subarray preprocessing module is electrically connected to a second self-calibration coupler. Each subarray preprocessing module also includes a second digital-to-analog converter (DAC) and a second analog-to-digital converter (ADC). Both the second DAC and the ADC are electrically connected to a signal processing submodule. In one implementation of the first aspect, for each of the multiple transceiver channels, the transceiver channel includes a first transceiver switch, a receiving sub-channel, a transmitting sub-channel, and a second transceiver switch, which are electrically connected in sequence. The first transceiver switch is provided with a first port, a second port, and a third port. The first port of the first transceiver switch is electrically connected to a first self-test calibration coupler, the second port of the first transceiver switch is electrically connected to one end of the receiving sub-channel, and the third port of the first transceiver switch is electrically connected to one end of the transmitting sub-channel. The second transceiver switch is provided with a first port, a second port, and a third port. The first port of the second transceiver switch is electrically connected to the other end of the receiving sub-channel, the second port of the second transceiver switch is electrically connected to the other end of the transmitting sub-channel, and the third port of the second transceiver switch is electrically connected to a delay unit and an attenuator in sequence. The attenuator is electrically connected to a combiner / splitter.

[0006] In one implementation of the first aspect, the receiving subchannel includes a receiving low-noise amplifier and a first bandpass filter connected in sequence; the transmitting subchannel includes a transmitting amplifier circuit and a second bandpass filter connected in sequence.

[0007] In one implementation of the first aspect, the signal processing submodule includes an embedded processor and a host computer electrically connected in sequence. The embedded processor is electrically connected to a first digital-to-analog converter, a first analog-to-digital converter, a second digital-to-analog converter, and a second analog-to-digital converter.

[0008] Secondly, the present invention provides an in-flight self-test calibration method for a time-controlled array radar based on the method provided in the first aspect, comprising: using a signal processing submodule to determine the type of in-flight self-test calibration for the time-controlled array radar, wherein the type of in-flight self-test calibration includes transmit self-test calibration of the transmit / receive channel, receive self-test calibration of the transmit / receive channel, transmit self-test calibration of the subarray preprocessing module, and receive self-test calibration of the subarray preprocessing module. A switching submodule selects the detection component and operating state corresponding to the type of in-flight self-test calibration; the detection component is either the transmit / receive channel or the subarray preprocessing module, and the operating state is transmit or receive. A first self-test calibration coupler / second self-test calibration coupler corresponding to the detection component and operating state acquires the transmit / receive signals, and outputs the transmit / receive signals to the signal processing submodule via a first digital-to-analog converter / first analog-to-digital converter. The signal processing submodule compares the transmit / receive signals output by the first digital-to-analog converter / first analog-to-digital converter with the transmit / receive signals output by the second digital-to-analog converter and the second analog-to-digital converter for amplitude consistency and delay consistency, and adjusts the detection component according to the comparison results to achieve in-flight self-test calibration of the time-controlled array radar.

[0009] In one implementation of the second aspect, when the type of in-system self-test calibration is transmit / receive self-test calibration of the transceiver channel, the in-system self-test calibration process of the time-controlled array radar is as follows: The signal processing submodule sets the operating mode of both the subarray preprocessing module and the subarray module to transmit / receive mode; it switches the transmit / receive self-test selection switch to transmit up-conversion / receive down-conversion state, switches the self-test component selection switch to transceiver component self-test calibration state, selects the corresponding transceiver component using the transceiver component selection switch, and selects the corresponding self-test transceiver channel using the channel selection switch. The first self-test calibration coupler electrically connected to the self-test transceiver channel acquires the ultra-wideband pulse signal transmitted / received by the self-test transceiver channel. After the ultra-wideband pulse signal is up-converted / down-converted and amplified by the channel selection switch, transceiver component selection switch, self-test component selection switch, and mixer, it is transmitted to the signal processing submodule through the first analog-to-digital converter / first digital-to-analog converter. The signal processing submodule compares the amplitude consistency and delay consistency of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter with the ultra-wideband pulse signal transmitted by the second digital-to-analog converter / second analog-to-digital converter. It then obtains the comparison result of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter and adjusts the self-test transceiver channel according to the comparison result to realize the in-system self-test calibration of the time-controlled array radar.

[0010] In one implementation of the second aspect, when the type of in-flight self-test calibration is the transmit / receive self-test calibration of the subarray preprocessing module, the in-flight self-test calibration process of the time-controlled array radar is as follows: the signal processing submodule powers off all subarray modules; the transmit / receive self-test selection switch is switched to the transmit upconversion / receive downconversion state, the self-test part selection switch is switched to the subarray preprocessing module self-test calibration state, and the corresponding self-test signal processing submodule is selected using the subarray module selection switch; the second digital-to-analog converter electrically connected to the self-test signal processing submodule transmits the self-test waveform, and the self-test waveform passes through the self-test signal processing submodule and the second self-test calibration submodule electrically connected to the self-test signal processing submodule. After up-conversion / down-conversion and amplification by the quasi-coupler, subarray module selection switch, self-test part selection switch, transmit / receive self-test selection switch, and mixer, the signal is transmitted to the signal processing submodule via the first analog-to-digital converter / first digital-to-analog converter. The signal processing submodule compares the amplitude consistency and delay consistency of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter with the self-test waveform transmitted by the second digital-to-analog converter / second analog-to-digital converter to obtain the comparison result of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter. Based on the comparison result, the self-test signal processing submodule is adjusted to realize the in-system self-test calibration of the time-controlled array radar.

[0011] Compared with the prior art, the present invention has the following beneficial effects.

[0012] (1) The self-test calibration method of the present invention can quickly and accurately detect the time delay consistency and amplitude consistency of each transceiver channel and each subarray preprocessing module in the receive / transmit mode. Specifically, the delay time is obtained by performing cross-correlation operation on the acquired test signal and self-test signal in the digital domain, and by performing sine interpolation fitting near the cross-correlation peak. The above process automatically analyzes the amplitude and time information of the self-test signal in the digital domain, which has the advantages of high accuracy and high speed, and is suitable for large-scale time-controlled array radar.

[0013] (2) The self-test calibration method of the present invention realizes time-division and traversal self-test of a large number of transceiver channels and subarray preprocessing modules through the self-test component selection switch, the transceiver self-test selection switch, the transceiver component selection switch, and the transceiver channel selection switch in the transceiver component. Through the high isolation performance of the multi-level switches, it ensures that the self-test calibration of each channel and module does not affect each other, thereby improving the accuracy and stability of the self-test calibration. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a time-controlled array radar provided in an embodiment of this application; Figure 2 This is a schematic diagram of an in-flight self-test calibration method for a time-controlled array radar provided in an embodiment of this application. Detailed Implementation

[0015] In the specification and claims of this invention, the terms "first" and "second," etc., are used to distinguish different objects, rather than to describe a specific order of objects.

[0016] In the embodiments of this application, "and / or" indicates a relationship between objects. For example, A and / or B can represent the following three situations: A exists alone, B exists alone, and A and B exist simultaneously.

[0017] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0018] In the description of this invention, unless otherwise stated, "a plurality of" means two or more. For example, a plurality of subarray modules means two or more subarray modules; a plurality of transceiver components means two or more transceiver components; a plurality of transceiver channels means two or more transceiver channels.

[0019] The method and apparatus provided in this application relate to the performance testing of array radar and can be used for the in-flight self-test calibration of time-controlled array radar.

[0020] Understandably, since array radars typically contain a large number of subarray modules, they require high-precision amplitude and delay consistency to ensure normal beamforming and scanning. Currently, there are many methods for onboard self-calibration of phased array radars, but methods for time-controlled array radars are lacking, making it unsuitable to directly apply phased array radar methods. Phased array radars typically have wide pulse widths, ranging from 1µs to 100µs, containing many carrier frequency cycles within a single pulse width, allowing the array to synthesize across these cycles. Time-controlled array radars, on the other hand, have very narrow pulse widths, from 0.1ns to several ns, with waveforms within the pulse being Gaussian pulses or the nth derivative of Gaussian pulses. Generally, the number of waveform cycles within a pulse is only about 1-2, making cross-carrier frequency synthesis impossible. Furthermore, the phase shifters used in phased array radars cause broadband time-domain waveform dispersion, distortion of UWB impulse pulse waveforms, beam pointing deviations, and even the inability to synthesize beams.

[0021] Self-calibration of phased array radar typically measures the channel amplitude and phase difference at different operating frequencies. However, for UWB impulses, due to their extremely narrow pulses and large bandwidth, measuring the amplitude and delay difference at a single frequency point does not allow for quantitative calculation of the amplitude and delay difference of the UWB time-domain waveform. Considering the characteristics of the UWB time-domain impulse waveform used in time-controlled arrays, directly measuring the time-domain delay and amplitude of each channel in the time domain would be more suitable for time-controlled array radars.

[0022] To address the current lack of an onboard self-test calibration method for time-controlled array radars, which prevents the normal operation of such radars from being guaranteed, this application provides a time-controlled array radar and its onboard self-test calibration method. This method enables onboard self-test calibration of the time-controlled array radar, thereby ensuring its normal operation.

[0023] For example, an embodiment of this application provides a time-controlled array radar, including a self-test calibration control module, multiple parallel subarray modules, and multiple parallel subarray preprocessing modules. It is understood that the aforementioned multiple subarray modules and multiple subarray preprocessing modules are all designed with embedded processors and software to perform 485 communication, timed acquisition of voltage, current, and temperature, and analysis and interpretation of data normality.

[0024] The self-test calibration control module described above will be introduced in detail below.

[0025] The aforementioned self-test calibration control module is used for the in-flight self-test calibration of the time-controlled array radar.

[0026] In one application scenario, the self-test calibration control module includes an up / down frequency conversion module, a switch submodule, a coupler submodule, and a signal processing submodule.

[0027] The aforementioned up-conversion and down-conversion modules include a mixer and a first digital-to-analog converter (ADC) and a first analog-to-digital converter (DAC) electrically connected to the mixer, respectively. The aforementioned switch submodule includes a transmit / receive self-test selection switch, a self-test location selection switch, a subarray module selection switch, a transmit / receive component selection switch, and a channel selection switch. The aforementioned coupler submodule includes multiple first self-test calibration couplers and multiple second self-test calibration couplers. The aforementioned signal processing submodule is used to perform self-test calibration on the subarray modules and subarray preprocessing modules. The signal processing submodule includes an embedded processor (such as a microcontroller) and a host computer electrically connected in sequence. It is understood that the aforementioned signal processing submodule may also include terminal software and display software deployed on the host computer, which can be used to configure the operating status of various components in the time-controlled array radar.

[0028] It should be noted that the terminal software and display software deployed on the host computer can manually or automatically select the self-test mode (transmit or receive), self-test component (transceiver module or subarray preprocessing circuit), and self-test channel (TR channel number or subarray preprocessing module number), control the generation of self-test waveforms (UWB impulse pulses), and acquire the radar response waveforms (UWB impulse pulses). Accurate delay values ​​for each channel are obtained through autocorrelation calculations and sine interpolation processing; the attenuation and delay values ​​of each channel are controlled, as well as power-on operation; and voltage, current, and temperature data of each component are acquired and displayed. The host computer communicates with the embedded processor and the radar's beam control circuit via a 485 interface, transmitting control commands and receiving temperature, voltage, and current data. The aforementioned self-test waveform uses a high-speed DAC output, with a pulse width selectable between 0.5 and 5 ns, a maximum amplitude of 5 dBm, a sampling rate of 10 Gsps, and a bit width of 14 bits. The acquisition of the aforementioned radar response waveform is achieved using a high-speed ADC, with a sampling rate as high as 10 Gsps and a bit width of 14 bits. The correlation operations and sine interpolation processing performed in the digital domain in this invention enable time measurement accuracy to reach 10 ps and amplitude measurement accuracy to reach 0.1 dB.

[0029] Furthermore, the mixer in the aforementioned up-conversion / down-conversion module is electrically connected in sequence to the transmit / receive self-test selection switch and the self-test component selection switch. The self-test component selection switch is electrically connected to the subarray module selection switch and the transmit / receive component selection switch, respectively. Multiple first self-test calibration couplers in the aforementioned coupler submodule are electrically connected to the channel selection switch, and multiple second self-test calibration couplers are electrically connected to the subarray module selection switch. The embedded processor in the aforementioned signal processing submodule is electrically connected to the first digital-to-analog converter, the first analog-to-digital converter, the second digital-to-analog converter, and the second analog-to-digital converter.

[0030] The following section provides a detailed introduction to the multiple subarray modules listed above.

[0031] Multiple subarray modules arranged in parallel are used to receive and / or transmit ultra-wideband pulse signals.

[0032] For each of the multiple subarray modules, the subarray module is electrically connected to a subarray preprocessing module. The subarray module includes parallel combiners / splitters and multiple transceiver components (also called TR components). For each of the multiple transceiver components, the transceiver component includes multiple transceiver channels in parallel.

[0033] For each of the multiple transceiver channels, one end of the transceiver channel is electrically connected to a first self-test calibration coupler, and the other end is electrically connected to a combiner / splitter. The first self-test calibration coupler is also electrically connected to an antenna. Specifically, for each of the multiple transceiver channels, the transceiver channel (also called a TR channel) includes a first transceiver switch (or circulator), a receiver sub-channel, a transmitter sub-channel, and a second transceiver switch, which are electrically connected in sequence. The first transceiver switch has a first port, a second port, and a third port. The first port of the first transceiver switch is electrically connected to the first self-test calibration coupler, the second port of the first transceiver switch is electrically connected to one end of the receiver sub-channel, and the third port of the first transceiver switch is electrically connected to one end of the transmitter sub-channel. The second transceiver switch also has a first port, a second port, and a third port. The first port of the second transceiver switch is electrically connected to the other end of the receiver sub-channel, the second port of the second transceiver switch is electrically connected to the other end of the transmitter sub-channel, and the third port of the second transceiver switch is electrically connected in sequence to a delay unit and an attenuator; the attenuator is electrically connected to the combiner / splitter.

[0034] Optionally, the receiving sub-channel includes a receiving low-noise amplifier (LNA) and a first bandpass filter connected in sequence. The transmitting sub-channel includes a transmitting amplifier circuit and a second bandpass filter connected in sequence.

[0035] The following section provides a detailed introduction to the multiple subarray preprocessing modules listed above.

[0036] Multiple parallel subarray preprocessing modules (also called subarray preprocessing circuits) are used to process the aforementioned ultra-wideband pulse signals. Specifically, these multiple subarray preprocessing modules are used to process ultra-wideband pulse signals received by the multiple subarray modules, or to preprocess ultra-wideband pulse signals that need to be transmitted by the multiple subarray modules. The processing / preprocessing can include partial beamforming (preliminary beamforming at the subarray level to form a wider subarray beam), signal conditioning (including amplification, filtering, mixing, etc., to ensure signal quality), data compression (merging channels in analog or digital ways to reduce the amount of data transmitted to the backend), or anti-interference, etc.

[0037] The aforementioned subarray preprocessing module can be an analog subarray preprocessing module, a digital subarray preprocessing module, or a hybrid subarray preprocessing module. Since the aforementioned subarray preprocessing module belongs to the prior art, this application embodiment does not further limit the specific components and connection methods of the aforementioned subarray preprocessing module.

[0038] For each of the multiple subarray preprocessing modules, the subarray preprocessing module is electrically connected to a second self-test calibration coupler; the subarray preprocessing module is also provided with a second digital-to-analog converter and a second analog-to-digital converter; both the second digital-to-analog converter and the second analog-to-digital converter are electrically connected to the signal processing submodule.

[0039] refer to Figure 1 , Figure 1 The structure is illustrated using the four subarray modules in the aforementioned time-controlled array radar as an example. Each subarray module contains four transceiver components. Figure 1 Only one transceiver component is shown in the image. Each transceiver component contains four transceiver channels, and each subarray module is connected to a subarray preprocessing module. Figure 1 The preprocessing modules for subarray 1, subarray 2, subarray 3, and subarray 4 are described above. The first self-test calibration coupler in the aforementioned time-controlled array radar corresponds to... Figure 1 The coupler in the mid-transmit / receive channel, the second self-test calibration coupler corresponds to Figure 1 The coupler in the neutron array preprocessing module, the first bandpass filter corresponds to Figure 1 The first bandpass and second bandpass filters in the middle correspond to Figure 1 The second bandpass in the above-mentioned receiving low-noise amplifier corresponds to... Figure 1 The LNA in the above-mentioned first digital-to-analog converter corresponds to... Figure 1 The DAC-5 in the above-mentioned first analog-to-digital converter corresponds to... Figure 1 The ADC-5 mentioned above corresponds to the second digital-to-analog converter. Figure 1 The DAC-1, DAC-2, DAC-3, and DAC-4 mentioned above correspond to the I-ADC and Q-ADC in Figure 1.

[0040] Refer to the above Figure 1 The aforementioned time-controlled array radar employs a first self-calibration coupler and a second self-calibration coupler installed within the subarray preprocessing module and transceiver channel to feed the self-calibration signal into the receiving channel, or to couple out a portion of the transmitted signal for detection. The couplers possess broadband and low dispersion characteristics, with coupling coefficients selected within the range of -20 to -60 dB depending on the specific radar. The coupler insertion loss is better than -0.2 dB, having a negligible impact on normal channel transmission and reception.

[0041] The aforementioned time-controlled array radar employs multi-level switches to achieve switching of transmit and receive self-tests, switching of self-test components (subarray preprocessing modules or transmit / receive components), switching of self-test transmit / receive components, switching of transmit / receive channels, and switching of subarray preprocessing modules. Various scales are available, such as 1:2 switches, 1:4 switches, and 1:8 switches. The switching speed is less than 50 ns, the isolation is greater than 30 dB, and the insertion loss is less than 2 dB, ensuring the speed and accuracy of self-test calibration for large-scale arrays.

[0042] The aforementioned time-controlled array radar incorporates a self-test calibration control module. This module interconnects the radar's components via cables, serving as a common part of the self-test calibration process. The performance parameters of this module do not affect the self-test calibration data. The self-test calibration control module includes up-conversion and down-conversion functions, utilizing a coherent continuous wave local oscillator to convert intermediate frequency UWB impulse pulse signals to microwave UWB impulse pulse signals, or vice versa.

[0043] like Figure 2 As shown in the embodiment of this application, an in-flight self-test calibration method for the aforementioned time-controlled array radar includes S101-S104.

[0044] S101. The signal processing submodule is used to determine the type of in-flight self-test calibration of the time-controlled array radar.

[0045] The types of in-system self-test calibrations mentioned above include transmit self-test calibration of the transmit and receive channels, transmit self-test calibration of the subarray preprocessing module, and receive self-test calibration of the subarray preprocessing module.

[0046] S102. Select the detection component and working status corresponding to the type of in-machine self-test calibration through the switch submodule.

[0047] The aforementioned detection components are transceiver channels or subarray preprocessing modules, and their operating states are transmission or reception.

[0048] S103. The first self-test calibration coupler / second self-test calibration coupler corresponding to the detection component and working state are used to acquire the transmitted / received signals, and the transmitted / received signals are output to the signal processing submodule through the first digital-to-analog converter / first analog-to-digital converter.

[0049] S104 The signal processing submodule compares the transmitted / received signals output by the first digital-to-analog converter / first analog-to-digital converter with the transmitted / received signals output by the second digital-to-analog converter and the second analog-to-digital converter for amplitude consistency and delay consistency, and adjusts the detection components according to the comparison results to achieve the in-flight self-test calibration of the time-controlled array radar.

[0050] In one implementation, when the type of in-system self-test calibration is transmit / receive self-test calibration of the transceiver channel, the in-system self-test calibration process of the time-controlled array radar includes the following steps 1.1 to 1.3.

[0051] Step 1.1: The signal processing submodule sets the working mode of both the subarray preprocessing module and the subarray module to transmit / receive mode; switches the transmit / receive self-test selection switch to transmit upconversion / receive downconversion state, switches the self-test component selection switch to transmit / receive component self-test calibration state, selects the corresponding transmit / receive component using the transmit / receive component selection switch, and selects the corresponding self-test transmit / receive channel using the channel selection switch.

[0052] Step 1.2: The first self-test calibration coupler, which is electrically connected to the self-test transceiver channel, acquires the ultra-wideband pulse signal transmitted / received by the self-test transceiver channel. After the ultra-wideband pulse signal is up-converted / down-converted and amplified by the channel selection switch, transceiver component selection switch, self-test part selection switch and mixer, it is transmitted to the signal processing submodule through the first analog-to-digital converter / first digital-to-analog converter.

[0053] Step 1.3: The signal processing submodule compares the amplitude consistency and delay consistency of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter with the ultra-wideband pulse signal transmitted by the second digital-to-analog converter / second analog-to-digital converter. It then obtains the comparison result of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter and adjusts the self-test transceiver channel according to the comparison result to realize the in-system self-test calibration of the time-controlled array radar.

[0054] In one application scenario of the above implementation method, the structure of the aforementioned time-controlled array radar is as follows: Figure 1 As shown, when the type of in-flight self-test calibration is transmit self-test calibration of the transmit / receive channel, the in-flight self-test calibration process of the time-controlled array radar is as follows.

[0055] The subarray preprocessing module operates in transmit mode. The terminal software is configured to ensure that the TR channel operates in transmit timing, and the transmit / receive switches within the TR channel are switched to transmit mode.

[0056] The self-test calibration control module switches the transmit / receive self-test selection switch to receive downconversion mode, switches the self-test component selection switch to TR component self-test calibration mode, and selects the transmit / receive component of the TR channel that needs to be self-tested and calibrated.

[0057] Subarray 1's TR channels 1-16 operate in transmit mode. A small portion of the waveform of the transmitted ultra-wideband pulse signal from each TR channel is separated for testing by the first self-test calibration coupler. This waveform then passes through an internal 1:8 channel selection switch to select the transmit channel currently undergoing self-test or calibration, and a 1:4 transceiver selection switch to select the TR module requiring self-test. Finally, the ultra-wideband pulse signal coupled to the transmit channel is down-converted and amplified via a cable interconnection self-test selection switch and a "transceiver self-test selection switch," before being sent to an ADC-5 for acquisition. The digital stream signal acquired by the ADC5, after digital domain analysis, provides the transmit signal amplitude of the TR channel and its time delay relative to the DAC-1 transmit signal. By comparison, the transmit performance of the current channel can be determined. Simultaneously, the software can configure the transmitter attenuator value of the TR channel, using the ADC-5 to determine if the transmit attenuation is functioning correctly. The software can also configure the transmit pulse delay value of the TR channel, using the ADC-5 to acquire the signal and compare the time difference with the DAC-1 transmit signal to determine if the delay control of the transmit channel is functioning correctly.

[0058] This method can detect whether the gain, delay, and attenuation functions of the TR transmission are normal. If there is an amplitude difference between channels, it can be compensated by a digitally controlled attenuator; if there is a delay difference between channels, it can be compensated by a digitally controlled delay unit. The delay time difference between the ADC-5 waveform and the DAC-1 waveform is processed using the digital domain cross-correlation method. Sine interpolation is performed on the correlation result near the cross-correlation peak to fit a more accurate peak time. The interpolation process improves the accuracy of the delay time obtained by the cross-correlation method to 0.1Ts. Here, Ts is the sampling rate of the digital stream. The ADC sampling circuit in the above-mentioned time-controlled array radar has a sampling rate as high as 10Gsps, and the delay measurement accuracy can reach 10ps; the ADC sampling bit depth is 10 bits, and the amplitude quantization accuracy can be better than 0.1dB. Repeat the above process to complete the transmission self-test and calibration of 64 TR channels for 4 transceiver components in sequence.

[0059] When the type of internal self-test calibration is the receive self-test calibration of the transmit / receive channel, the internal self-test calibration process of the time-controlled array radar is as follows.

[0060] The subarray preprocessing module operates in receive mode. The terminal software is configured to ensure that the TR channel operates in receive timing, and the transmit / receive switches within the TR channel are switched to receive mode.

[0061] The self-test calibration control module switches the transmit / receive self-test selection switch to transmit up-conversion mode, the self-test component selection switch to TR component self-test calibration mode, and the 1:4 transceiver component selection switch selects the transceiver component containing the TR channel that needs self-test calibration. When TR channels 1-16 of subarray 1 are undergoing receive self-test, DAC-5 generates self-test calibration pulse signals. These signals are up-converted and amplified by the self-test calibration control module, interconnected via cable to the "1:4 self-test component selection switch," and then select transceiver component 1. The "1:16 channel selection switch" within transceiver component 1 connects the TR channel that needs self-test, and the signals are fed into the "self-test calibration couplers" of the 16 TR channels within transceiver component 1. The self-test signals are fed into the TR channels, amplified by low noise, and combined by a 1:16 combiner before being down-converted and amplified by the subarray preprocessing module. Finally, they are acquired by I-ADC and Q-ADC, and digital domain analysis and comparison are performed to confirm whether each receiving channel is normal. This process is repeated to complete the receive self-test for channels 1-16 of subarray.

[0062] This method can detect whether the gain, delay, attenuation, and other functions of the receiving section of each TR channel are normal. If there is an amplitude difference between channels, it can be compensated by a digitally controlled attenuator; if there is a delay difference between channels, it can be compensated by a digitally controlled delay unit. The delay time difference between the DAC-5 waveform and the I-ADC waveform is also processed using the digital domain cross-correlation method, and sine interpolation is used to improve the delay time accuracy of the cross-correlation method to 0.1Ts. The TR receiving self-test of subarrays 2, 3, and 4 is the same as above.

[0063] Of course, self-tests can also be performed on the voltage, current, and temperature of the aforementioned transceiver components. Specifically, the operating voltage, current, and temperature of each transceiver component (including 16 TR channels) can be self-tested; the operating current is converted into a voltage value, which is then collected by the internal embedded processor to determine whether it is normal or not. Only the normal or not determination result is stored for the operating voltage and current, while the specific temperature value is stored. The internal embedded processor periodically collects these parameters and stores the results. When the user queries or performs a power-on self-test, the most recent self-test result from the embedded processor is directly retrieved and uploaded to the host computer for display via RS-485.

[0064] In another implementation, when the type of in-flight self-test calibration is the transmit / receive self-test calibration of the subarray preprocessing module, the in-flight self-test calibration process of the time-controlled array radar includes the following steps 2.1 to 2.3.

[0065] Step 2.1: The signal processing submodule powers off all subarray modules; switches the transmit / receive self-test selection switch to transmit upconversion / receive downconversion state, switches the self-test part selection switch to subarray preprocessing module self-test calibration state, and selects the corresponding self-test signal processing submodule using the subarray module selection switch.

[0066] Step 2.2: The second digital-to-analog converter electrically connected to the self-test signal processing submodule transmits the self-test waveform. The self-test waveform is up-converted / down-converted and amplified by the self-test signal processing submodule, the second self-test calibration coupler electrically connected to the self-test signal processing submodule, the subarray module selection switch, the self-test part selection switch, the transmit / receive self-test selection switch, and the mixer, and then transmitted to the signal processing submodule through the first analog-to-digital converter / first digital-to-analog converter.

[0067] Optionally, the aforementioned self-test waveform (UWB impulse pulse) uses a high-speed DAC output, with a pulse width selectable between 0.5 and 5 ns, a maximum amplitude of 5 dBm, a sampling rate of 10 Gsps, and a bit width of 14 bits. The acquisition of the aforementioned radar response waveform is achieved using a high-speed ADC, with a sampling rate as high as 10 Gsps and a bit width of 14 bits. The correlation operations and sine interpolation processing performed in the digital domain in this invention enable a time measurement accuracy of up to 10 ps and an amplitude measurement accuracy of 0.1 dB.

[0068] Step 2.3: The signal processing submodule compares the amplitude consistency and delay consistency of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter with the self-test waveform transmitted by the second digital-to-analog converter / second analog-to-digital converter. It then obtains the comparison result of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter and adjusts the self-test signal processing submodule according to the comparison result to realize the in-flight self-test calibration of the time-controlled array radar.

[0069] In one application scenario of the above implementation method, when the type of in-flight self-test calibration is the transmit self-test calibration of the subarray preprocessing module, the in-flight self-test calibration process of the time-controlled array radar is as follows.

[0070] Taking the preprocessing module of subarray 1 as an example for analysis. At this time, all four subarray modules enter the power-off mode. The self-test component selection switch activates the subarray preprocessing module, and the transmit / receive self-test selection switch switches to the receive down-conversion state.

[0071] DAC-1 generates a transmit self-test waveform, while other DACs have no output. The waveform is amplified and up-converted by the subarray 1 preprocessing module, and the internal transmit / receive switch is set to transmit mode. A small portion of the detection signal is split off by the coupler and sent to the self-test component selection switch via a 1:4 switch. After down-conversion, it is sent to ADC-5 for acquisition to confirm whether the current subarray 1 preprocessing module's transmission is normal. This process can detect whether the preprocessing gain, power, and delay are normal; the transmit function self-test process of other subarray preprocessing modules is similar.

[0072] When the type of in-system self-test calibration is the receiver self-test calibration of the subarray preprocessing module, the in-system self-test calibration process of the time-controlled array radar is as follows.

[0073] Taking the subarray 1 preprocessing module as an example for analysis. At this time, all four subarray modules enter the power-off mode. The self-test component selection switch activates the subarray preprocessing module, and the transmit / receive self-test selection switch switches to the transmit upconversion state.

[0074] DAC-5 generates an ultra-wideband impulse waveform for transmit self-test. Other DACs have no output. After amplification and up-conversion by the internal circuitry of the self-test calibration control module, the transmit / receive self-test selection switch is set to receive mode. The signal is then fed into the 1:4 switch inside the subarray preprocessing module via the self-test component selection switch, switching to the subarray preprocessing module under test. The coupler inside this circuit feeds the detection signal to the corresponding preprocessing circuit. At this time, the switch of the preprocessing circuit is set to receive mode. After amplification and down-conversion by the preprocessing circuit, the signal is sent to the I-ADC and Q-ADC for acquisition to confirm whether the reception of the current subarray 1's subarray preprocessing module is normal. This process can detect whether the receive gain, attenuation, and delay of the preprocessing are normal. The self-test process for the receive function of the subarray preprocessing modules of other subarrays is similar.

[0075] Of course, the aforementioned subarray preprocessing module also has a current self-test function. Specifically, the embedded processor inside the subarray preprocessing module periodically collects the operating voltage and current of the preprocessing board, determines whether it is normal, and stores the results. When the user queries or performs a power-on self-test, it directly calls the most recent self-test result of the embedded processor and uploads it to the host computer for display via RS-485. This method greatly improves the data acquisition speed and shortens the data refresh latency.

[0076] Therefore, it can be seen that when the radar in this embodiment performs self-tests on the voltage and current of the transceiver components and subarray preprocessing modules, it uses the built-in microcontroller within the components to collect voltage, current, and temperature data, and determine whether the data is normal or not. Only the judgment results of whether the voltage and current are normal are uploaded, reducing the amount of communication data. Simultaneously, the above parameters can be self-tested periodically, and the self-test results can be stored. When the user needs the self-test results, the most recent self-test result can be directly uploaded through the 485 communication interface, greatly shortening the data refresh latency.

[0077] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A time-controlled array radar, characterized in that, It includes a self-test calibration control module, multiple parallel subarray modules, and multiple parallel subarray preprocessing modules; The self-test calibration control module is used for the in-system self-test calibration of the time-controlled array radar; the self-test calibration control module includes an up-conversion module, a switching submodule, a coupler submodule, and a signal processing submodule; the up-conversion module includes a mixer and a first digital-to-analog converter and a first analog-to-digital converter, which are electrically connected to the mixer respectively; The switch submodule includes a transmit / receive self-test selection switch, a self-test location selection switch, a subarray module selection switch, a transmit / receive component selection switch, and a channel selection switch; the coupler submodule includes multiple first self-test calibration couplers and multiple second self-test calibration couplers; the signal processing submodule is used to perform self-test calibration on the subarray module and the subarray preprocessing module; wherein, the first digital-to-analog converter and the first analog-to-digital converter are also electrically connected to the signal processing submodule; the mixer is also electrically connected in sequence to the transmit / receive self-test selection switch and the self-test location selection switch; the self-test location selection switch is electrically connected to the subarray module selection switch and the transmit / receive component selection switch respectively; the multiple first self-test calibration couplers are all electrically connected to the channel selection switch, and the multiple second self-test calibration couplers are all electrically connected to the subarray module selection switch; The parallel subarray modules are used to receive and / or transmit ultra-wideband pulse signals; for each of the multiple subarray modules, the subarray module is electrically connected to one of the subarray preprocessing modules; the subarray module includes parallel combiners / splitters and multiple transceiver components; for each of the multiple transceiver components, the transceiver component includes multiple parallel transceiver channels; For each of the plurality of transceiver channels, one end of the transceiver channel is electrically connected to the first self-test calibration coupler, and the other end is electrically connected to the combiner / splitter; the first self-test calibration coupler is also electrically connected to an antenna; The parallel subarray preprocessing modules are used to process the ultra-wideband pulse signal; for each of the multiple subarray preprocessing modules, the subarray preprocessing module is electrically connected to a second self-test calibration coupler; the subarray preprocessing module is also provided with a second digital-to-analog converter and a second analog-to-digital converter; the second digital-to-analog converter and the second analog-to-digital converter are both electrically connected to the signal processing submodule.

2. The radar as described in claim 1, characterized in that, For each of the plurality of transceiver channels, the transceiver channel includes a first transceiver switch, a receiving sub-channel, a transmitting sub-channel, and a second transceiver switch, which are electrically connected in sequence. The first transceiver switch is provided with a first port, a second port, and a third port. The first port of the first transceiver switch is electrically connected to the first self-test calibration coupler, the second port of the first transceiver switch is electrically connected to one end of the receiving sub-channel, and the third port of the first transceiver switch is electrically connected to one end of the transmitting sub-channel. The second transceiver switch is provided with a first port, a second port, and a third port. The first port of the second transceiver switch is electrically connected to the other end of the receiving sub-channel, the second port of the second transceiver switch is electrically connected to the other end of the transmitting sub-channel, and the third port of the second transceiver switch is electrically connected to a delay unit and an attenuator in sequence. The attenuator is electrically connected to the combiner / splitter.

3. The radar as described in claim 2, characterized in that, The receiving subchannel includes a receiving low-noise amplifier and a first bandpass filter connected in sequence; The transmitting sub-channel includes a transmitting amplifier circuit and a second bandpass filter connected in sequence.

4. The radar as described in claim 1, characterized in that, The signal processing submodule includes an embedded processor and a host computer that are electrically connected in sequence; The embedded processor is electrically connected to the first digital-to-analog converter, the first analog-to-digital converter, the second digital-to-analog converter, and the second analog-to-digital converter.

5. An in-flight self-test calibration method for a time-controlled array radar as described in claim 1, characterized in that, include: The signal processing submodule is used to determine the type of in-system self-test calibration of the time-controlled array radar. The type of in-system self-test calibration includes the transmit self-test calibration of the transmit and receive channels, the transmit self-test calibration of the subarray preprocessing module, and the receive self-test calibration of the subarray preprocessing module. The switching submodule is used to select the detection component and operating state corresponding to the type of internal self-test calibration; the detection component is a transceiver channel or a subarray preprocessing module, and the operating state is transmit or receive. The first self-test calibration coupler / second self-test calibration coupler corresponding to the detection component and the working state are used to acquire the transmitted / received signals, and the transmitted / received signals are output to the signal processing submodule through the first digital-to-analog converter / first analog-to-digital converter; The signal processing submodule compares the transmitted / received signals output by the first digital-to-analog converter / first analog-to-digital converter with the transmitted / received signals output by the second digital-to-analog converter and the second analog-to-digital converter for amplitude consistency and delay consistency, and adjusts the detection components according to the comparison results to achieve in-flight self-test calibration of the time-controlled array radar.

6. The in-machine self-test calibration method as described in claim 5, characterized in that, When the type of the internal self-test calibration is the transmit / receive self-test calibration of the transceiver channel, the internal self-test calibration process of the time-controlled array radar is as follows: The signal processing submodule sets the working mode of the subarray preprocessing module and the working mode of the subarray module to transmit / receive mode; switches the transmit / receive self-test selection switch to transmit upconversion / receive downconversion state, switches the self-test part selection switch to transmit / receive component self-test calibration state, selects the corresponding transmit / receive component using the transmit / receive component selection switch, and selects the corresponding self-test transmit / receive channel using the channel selection switch. The first self-test calibration coupler electrically connected to the self-test transceiver channel acquires the ultra-wideband pulse signal transmitted / received by the self-test transceiver channel. The ultra-wideband pulse signal is up-converted / down-converted and amplified by the channel selection switch, the transceiver component selection switch, the self-test part selection switch, and the mixer, and then transmitted to the signal processing submodule through the first analog-to-digital converter / first digital-to-analog converter. The signal processing submodule compares the amplitude consistency and delay consistency of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter with the ultra-wideband pulse signal transmitted by the second digital-to-analog converter / second analog-to-digital converter to obtain the comparison result of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter. Based on the comparison result, the self-test transceiver channel is adjusted to realize the in-flight self-test calibration of the time-controlled array radar.

7. The in-machine self-test calibration method as described in claim 5, characterized in that, When the type of the in-flight self-test calibration is the transmit / receive self-test calibration of the subarray preprocessing module, the in-flight self-test calibration process of the time-controlled array radar is as follows: The signal processing submodule power off all subarray modules; Switch the transmit / receive self-test selection switch to transmit upconversion / receive downconversion state, switch the self-test part selection switch to subarray preprocessing module self-test calibration state, and use the subarray module selection switch to select the corresponding self-test signal processing submodule. The second digital-to-analog converter, electrically connected to the self-test signal processing submodule, transmits a self-test waveform. The self-test waveform undergoes up-conversion / down-conversion and amplification via the self-test signal processing submodule, the second self-test calibration coupler electrically connected to the self-test signal processing submodule, the subarray module selection switch, the self-test part selection switch, the transmit / receive self-test selection switch, and the mixer, and is then transmitted to the signal processing submodule via the first analog-to-digital converter / first digital-to-analog converter. The signal processing submodule compares the amplitude consistency and delay consistency of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter with the self-test waveform transmitted by the second digital-to-analog converter / second analog-to-digital converter to obtain the comparison result of the ultra-wideband pulse signal transmitted by the first analog-to-digital converter / first digital-to-analog converter. Based on the comparison result, the self-test signal processing submodule is adjusted to realize the in-flight self-test calibration of the time-controlled array radar.

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