阅读说明：本技术 一种用于雷达信号源的多通道中频信号产生方法 (Multichannel intermediate frequency signal generation method for radar signal source ) 是由 陈立明 章瑜 杨旭宏 于 2020-04-22 设计创作，主要内容包括：本发明涉及雷达信号,具体涉及一种用于雷达信号源的多通道中频信号产生方法,通过上位机向波形产生模块中的多路信号产生支路发送相应信号参数,多路信号产生支路根据信号参数生成不同形式的数字信号,对多路数字信号进行数字频率合成,经宽带D/A转换模块转换后,变成中频信号输出；本发明提供的技术方案能够有效克服现有技术所存在的信号种类单一、调节灵活性较差的缺陷。(The invention relates to radar signals, in particular to a multichannel intermediate frequency signal generating method for a radar signal source, which comprises the steps of sending corresponding signal parameters to a multichannel signal generating branch in a waveform generating module through an upper computer, generating digital signals of different forms by the multichannel signal generating branch according to the signal parameters, carrying out digital frequency synthesis on the multichannel digital signals, converting the digital signals into intermediate frequency signals through a broadband D/A converting module, and outputting the intermediate frequency signals; the technical scheme provided by the invention can effectively overcome the defects of single signal type and poor regulation flexibility in the prior art.)

1. A method for generating a multi-channel if signal for a radar signal source, comprising: the method comprises the following steps:

s1, sending corresponding signal parameters to a multi-path signal generating branch in the waveform generating module through the upper computer, and generating digital signals in different forms by the multi-path signal generating branch according to the signal parameters;

and S2, carrying out digital frequency synthesis on the multi-channel digital signals, converting the multi-channel digital signals into intermediate frequency signals through the broadband D/A conversion module, and outputting the intermediate frequency signals.

2. The multi-channel intermediate frequency signal generating method for a radar signal source according to claim 1, wherein: the waveform generation module comprises a control interface module for receiving signal parameters sent by an upper computer, signal generators for generating digital signals in different forms according to the signal parameters, a signal digital synthesis module for synthesizing the digital signals generated by the signal generators into digital intermediate frequency signals by a direct digital frequency synthesis technology, and a broadband D/A conversion module for converting the digital intermediate frequency signals into broadband analog intermediate frequency signals.

3. The multi-channel intermediate frequency signal generating method for a radar signal source according to claim 2, wherein: and the control interface module receives signal parameters sent by the upper computer through an Ethernet interface and an RS232 serial port.

4. The multi-channel intermediate frequency signal generating method for a radar signal source according to claim 2, wherein: the signal generator comprises a frequency phase modulation module and a pulse modulation module, wherein the frequency phase modulation module is used for generating a single-point frequency signal, a linear frequency modulation signal, a frequency coding signal, frequency diversity and a phase coding signal, and the pulse modulation module is connected with the frequency phase modulation module and is used for finishing signal pulse cutting according to pulse width and repetition frequency change.

5. The multi-channel intermediate frequency signal generating method for a radar signal source according to claim 4, wherein: the working process of the signal generator is as follows:

s1, the ADC chip finishes the acquisition of 1 path of broadband intermediate frequency signals, and the signals are sent to the FPGA through a J204B protocol for serial-parallel conversion and corresponding frequency mixing and filtering processing;

s2, the FPGA completes digital processing and analysis of the acquired signals and digital processing work of waveform generation;

and S3, the DAC chip converts the digital intermediate frequency signal generated by the FPGA into an analog intermediate frequency signal through the high-speed LVDS interface and sends the analog intermediate frequency signal.

6. The multi-channel intermediate frequency signal generating method for a radar signal source according to claim 1, wherein: and the upper computer inputs PDW description words to a signal digital synthesis module in the waveform generation module through a PDW playback branch circuit to generate a target signal of a corresponding simulated combat opponent.

Technical Field

The invention relates to radar signals, in particular to a multichannel intermediate frequency signal generation method for a radar signal source.

Background

At present, the training of electronic warfare equipment is difficult to improve in adaptability of training levels and complex electromagnetic environments of the electronic warfare equipment due to the fact that most of training signal environments are signal sources with backward performance and are single or simple signal generators with few parameter types and ranges can be set. The multi-channel intermediate frequency signal generation technology can simultaneously generate multi-channel signals with independently adjustable parameters, and the multi-channel signals are subjected to up-conversion and power amplification to radiate a complex electromagnetic signal environment for the actual combat training of electronic combat equipment.

The multi-channel intermediate frequency signal generation method for the radar signal source used by the existing electronic warfare equipment training mainly has the following defects: firstly, the training signal environment is single, and most of the training signals are older signal sources and signal generators distributed along with assembly in the past; secondly, the settable parameter types and ranges of the training signals are fewer, the parameter setting types are mostly frequency, pulse width and repetition frequency, the ranges are mostly single wave bands or specific equipment adaptive parameters, and therefore improvement of signal recognition capability of operators of electronic warfare equipment is greatly limited.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects in the prior art, the invention provides a multichannel intermediate frequency signal generation method for a radar signal source, which can effectively overcome the defects of single signal type and poor regulation flexibility in the prior art.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme:

a method of generating a multi-channel intermediate frequency signal for a radar signal source, comprising the steps of:

s1, sending corresponding signal parameters to a multi-path signal generating branch in the waveform generating module through the upper computer, and generating digital signals in different forms by the multi-path signal generating branch according to the signal parameters;

and S2, carrying out digital frequency synthesis on the multi-channel digital signals, converting the multi-channel digital signals into intermediate frequency signals through the broadband D/A conversion module, and outputting the intermediate frequency signals.

Preferably, the waveform generating module includes a control interface module for receiving signal parameters sent by the upper computer, a signal generator for generating digital signals of different forms according to the signal parameters, a signal digital synthesizing module for synthesizing the digital signals generated by the plurality of signal generators into digital intermediate frequency signals by a direct digital frequency synthesizing technique, and a wideband D/a converting module for converting the digital intermediate frequency signals into wideband analog intermediate frequency signals.

Preferably, the control interface module receives the signal parameter sent by the upper computer through an ethernet interface and an RS232 serial port.

Preferably, the signal generator comprises a frequency phase modulation module for generating a single-point frequency signal, a chirp signal, a frequency coding signal, a frequency diversity signal and a phase coding signal, and a pulse modulation module connected with the frequency phase modulation module and used for completing signal pulse cutting according to pulse width and repetition frequency changes.

Preferably, the signal generator operates as follows:

s1, the ADC chip finishes the acquisition of 1 path of broadband intermediate frequency signals, and the signals are sent to the FPGA through a J204B protocol for serial-parallel conversion and corresponding frequency mixing and filtering processing;

s2, the FPGA completes digital processing and analysis of the acquired signals and digital processing work of waveform generation;

and S3, the DAC chip converts the digital intermediate frequency signal generated by the FPGA into an analog intermediate frequency signal through the high-speed LVDS interface and sends the analog intermediate frequency signal.

Preferably, the upper computer inputs a PDW description word to a signal digital synthesis module in the waveform generation module through a PDW playback branch, and generates a target signal of a corresponding simulated competitor.

(III) advantageous effects

Compared with the prior art, the multi-channel intermediate frequency signal generation method for the radar signal source can generate a complex electromagnetic environment by simultaneously generating a plurality of radar signals in different forms, namely, the multi-channel intermediate frequency signal generation technology can simultaneously generate intermediate frequency signals with independent and adjustable multi-channel radar parameters.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic diagram of the method of the present invention;

FIG. 2 is a schematic block diagram of a wideband digital transceiver board used in the signal generator of the present invention;

FIG. 3 is a flow chart of the PDW playback algorithm in the present invention;

FIG. 4 is a schematic block diagram of an upconversion module of the present invention;

fig. 5 is a schematic block diagram of a local oscillation module and a clock unit according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A multi-channel if signal generating method for a radar signal source, as shown in fig. 1 to 3, comprising the steps of:

s1, sending corresponding signal parameters to a multi-path signal generating branch in the waveform generating module through the upper computer, and generating digital signals in different forms by the multi-path signal generating branch according to the signal parameters;

and S2, carrying out digital frequency synthesis on the multi-channel digital signals, converting the multi-channel digital signals into intermediate frequency signals through the broadband D/A conversion module, and outputting the intermediate frequency signals.

The upper computer adopts a portable computer, can complete the control of the host equipment through a wired or wireless network, and simultaneously realizes the functions of signal parameter editing, man-machine interaction and the like.

As shown in fig. 1, the waveform generating module includes a control interface module for receiving signal parameters sent by the upper computer, signal generators for generating digital signals of different forms according to the signal parameters, a signal digital synthesizing module for synthesizing the digital signals generated by the signal generators into digital intermediate frequency signals by a direct digital frequency synthesizing technique, and a wideband D/a converting module for converting the digital intermediate frequency signals into wideband analog intermediate frequency signals.

And the control interface module receives the signal parameters sent by the upper computer through the Ethernet interface and the RS232 serial port.

The signal generator comprises a frequency phase modulation module and a pulse modulation module, wherein the frequency phase modulation module is used for generating a single-point frequency signal, a linear frequency modulation signal, a frequency coding signal, frequency diversity and a phase coding signal, and the pulse modulation module is connected with the frequency phase modulation module and is used for finishing signal pulse cutting according to pulse width and repetition frequency change.

The working process of the signal generator is as follows:

s1, the ADC chip finishes the acquisition of 1 path of broadband intermediate frequency signals, and the signals are sent to the FPGA through a J204B protocol for serial-parallel conversion and corresponding frequency mixing and filtering processing;

s2, the FPGA completes digital processing and analysis of the acquired signals and digital processing work of waveform generation;

and S3, the DAC chip converts the digital intermediate frequency signal generated by the FPGA into an analog intermediate frequency signal through the high-speed LVDS interface and sends the analog intermediate frequency signal.

As shown in fig. 2, the signal generator adopts a 1GHz 3U broadband digital transceiver board, and a receiving link of the broadband digital transceiver board completes 1-channel broadband intermediate frequency signal acquisition, digital down-conversion, filtering extraction and forming a baseband signal; the transmitting link of the broadband digital receiving and transmitting board completes the generation of 1 path of broadband intermediate frequency signals (digital intermediate frequency or baseband signal interpolation), and the external interfaces comprise optical fibers (10Gbps), TTL, RS422, RS232 and gigabit network/hundred megabyte network (alternative).

The AD9625 chip finishes the acquisition of 1 path of broadband intermediate frequency signals, and the signals are sent to the FPGA through a J204B protocol for serial-parallel conversion and corresponding frequency mixing and filtering processing; the AD9739 chip converts the digital intermediate frequency waveform generated by the FPGA into an analog intermediate frequency signal through a high-speed LVDS interface and sends the analog intermediate frequency signal.

The FPGA completes digital processing and analysis of the acquired signals and digital processing work of waveform generation. The FPGA processing mainly considers the use condition of multiplier resources, the sampling clock of the ADC and the DAC is 2.4GHz, the clock processed by the multiplier inside the FPGA is 240MHz, and 10 paths of parallel processing are needed. The model of the FPGA is XC7VX690T2FFG1927, and 3600 multipliers are in total, so that the order of the filter is comprehensively determined according to specific requirements during program design.

As shown in fig. 3, the upper computer inputs a PDW description word to the signal digital synthesis module in the waveform generation module through the PDW playback branch, and generates a target signal corresponding to the simulated competitor.

And the operator sends a specified recording file to the upper computer and starts to play back. The upper computer sends the PDW data packet to the lower computer, the lower computer conducts PDW analysis on the PDW data packet, and a first intermediate frequency analog signal and a second intermediate frequency analog signal are output to reproduce a target signal simulating a competitor.

As a subsequent application of the technical solution of the present application, the broadband intermediate frequency analog signal generated in the technical solution of the present application may be subjected to frequency mixing with a local oscillator signal generated by the local oscillator module through the up-conversion module, the frequency mixed signal is divided into 3 frequency bands, and the signal of each frequency band is filtered by the band-pass filter, digitally attenuated, amplified, and finally subjected to the switch filtering to suppress the harmonic wave and output to the transmission channel.

As shown in fig. 4 and fig. 5, the 23.8GHz first local oscillation signal and the 22.35GHz to 40GHz second local oscillation signal generated by the local oscillation module in fig. 5 are input to the up-conversion module in fig. 4. The method for mixing the broadband intermediate frequency signal with the local oscillator signal through the up-conversion module comprises the following steps:

s1, firstly, the 1.8GHz intermediate frequency signal output by the broadband D/A conversion module in the waveform generation module is subjected to intermediate frequency band-pass filtering;

s2, carrying out first frequency mixing on the attenuated signal in S1 and a first local oscillator signal of 23.8GHz to obtain a high and medium frequency signal of 22 GHz;

and S3, filtering and amplifying the signal mixed in the S2, and mixing the signal with a second local oscillation signal of 22.35 GHz-40 GHz to obtain a signal of 0.35 GHz-18 GHz.

The input port and the output port of the transmitting channel are both provided with couplers for monitoring the interface state, and the coupling signals of the couplers are converted into TTL level signals and then reported to an external system unit.

As shown in fig. 5, both the first local oscillation signal and the second local oscillation signal are generated by a local oscillation module, and the local oscillation module includes two independent local oscillation sources, where the first local oscillation source is a point frequency source and has a frequency of 23.8 GHz; the second local vibration source is a frequency hopping source, and the frequency is 22.35 GHz-40 GHz.

The clock unit generates a 100MHz reference clock and a 2.4GHz sampling clock, wherein the 100MHz reference clock is mainly used as reference for the local oscillation module to generate the local oscillation signal after the 100MHz reference clock is directly output by power division amplification of the 100MHz crystal oscillator; the 2.4GHz sampling clock is mainly generated through a phase-locked loop, and then power is divided into two paths to be respectively amplified and output.

The local oscillator module and the clock unit are both realized by LDO, an internal FPGA adopts CPLD or SPI to communicate externally, an internal receiving and transmitting switch, attenuation, local oscillator frequency and sampling frequency are set, and relevant states of receiving and transmitting input/output detection and sampling clock locking are monitored and periodically reported to an external system unit.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.