阅读说明：本技术 一种雷达信号源 (Radar signal source ) 是由 杨旭宏 陈立明 章瑜 于 2020-04-22 设计创作，主要内容包括：本发明涉及雷达信号,具体涉及一种雷达信号源,包括主控计算机,与主控计算机相连用于将多路独立雷达信号通道生成的数字信号合成模拟中频信号的波形产生模块,与波形产生模块相连的用于将模拟中频信号进行上变频激励放大的上变频激励模块,与上变频激励模块相连的用于对信号进行放大的外置功放模块,以及与上变频激励模块直接相连或与外置功放模块相连用于模拟产生雷达信号的多波段天线；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 radar signal source, which comprises a main control computer, a waveform generation module, an up-conversion excitation module, an external power amplification module and a multiband antenna, wherein the waveform generation module is connected with the main control computer and is used for synthesizing digital signals generated by multiple independent radar signal channels into analog 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 radar signal source, comprising: the multi-band antenna comprises a main control computer, a waveform generation module, an up-conversion excitation module, an external power amplification module and a multi-band antenna, wherein the waveform generation module is connected with the main control computer and is used for synthesizing digital signals generated by multiple paths of independent radar signal channels into analog intermediate frequency signals, the up-conversion excitation module is connected with the waveform generation module and is used for carrying out up-conversion excitation amplification on the analog intermediate frequency signals, the external power amplification module is connected with the up-conversion excitation module and is used for amplifying the signals, and the multi-band antenna is directly connected with the up-conversion excitation module or is connected with the external power.

2. The radar signal source of claim 1, wherein: the waveform generation module comprises a control interface module for receiving radar parameters sent by the main control computer, signal generators for generating digital signals in different forms according to the radar parameters, a digital frequency 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 radar signal source of claim 2, wherein: and the control interface module receives radar parameters sent by the main control computer through an Ethernet interface and an RS232 serial port.

4. The radar signal source of 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. Radar signal source according to claim 4, wherein: the signal generator adopts a 1GHz 3U broadband digital transceiver board, and a receiving link of the broadband digital transceiver board finishes 1 path of broadband intermediate frequency signal acquisition, digital down-conversion and filtering extraction to form a baseband signal; and the transmitting link of the broadband digital transceiver board completes the generation of 1 path of broadband intermediate frequency signals.

6. The radar signal source of claim 2, wherein: the digital frequency synthesis module adopts a DDS FPGA based on cordic algorithm.

7. The radar signal source of claim 1, wherein: the up-conversion excitation module comprises a control module, an up-conversion module which is connected with the control module and is used for up-conversion excitation amplification of the intermediate frequency signal, a local oscillator module which is connected with the control module and the up-conversion module and is used for providing a local oscillator signal for the up-conversion module and a clock signal for the system, and a power module.

8. The radar signal source of claim 1, wherein: the multiband antenna and the external power amplifier module are equally divided into three wave bands of 0.2-2 GHz, 2-6 GHz and 6-18 GHz, wherein a circumferential antenna is adopted for 0.2-2 GHz, and ridge horn antennas are adopted for 2-6 GHz and 6-18 GHz.

9. The radar signal source of claim 8, wherein: the multiband antenna is installed on a reinforcing tripod, and the external power amplifier module is integrated into an independent chassis.

10. The radar signal source of claim 1, wherein: the device also comprises a secondary power supply module used for supplying power to the waveform generation module and the up-conversion excitation module, and a mobile alternating current power supply used for supplying alternating current to the system when no commercial power is available.

Technical Field

The invention relates to radar signals, in particular to 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 radar signal source used for the training of the existing electronic warfare equipment 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 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 radar signal source comprises a main control computer, a waveform generation module, an up-conversion excitation module, an external power amplification module and a multiband antenna, wherein the waveform generation module is connected with the main control computer and is used for synthesizing digital signals generated by multiple independent radar signal channels into analog intermediate-frequency signals, the up-conversion excitation module is connected with the waveform generation module and is used for carrying out up-conversion excitation amplification on the analog intermediate-frequency signals, the external power amplification module is connected with the up-conversion excitation module and is used for amplifying the signals, and the multiband antenna is directly connected with the up-conversion excitation module or is connected with the external power amplification module and is used for analog generation of radar.

Preferably, the waveform generating module includes a control interface module for receiving radar parameters sent by the host computer, a signal generator for generating digital signals of different forms according to the radar parameters, a digital frequency 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 broadband D/a converting module for converting the digital intermediate frequency signals into broadband analog intermediate frequency signals.

Preferably, the control interface module receives the radar parameter sent by the master control 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 adopts a 1GHz 3U broadband digital transceiver board, and a receiving link of the broadband digital transceiver board completes 1-path broadband intermediate-frequency signal acquisition, digital down-conversion and filtering extraction to form a baseband signal; and the transmitting link of the broadband digital transceiver board completes the generation of 1 path of broadband intermediate frequency signals.

Preferably, the digital frequency synthesis module adopts a DDS FPGA based on cordic algorithm.

Preferably, the up-conversion excitation module includes a control module, an up-conversion module connected to the control module and configured to perform up-conversion excitation amplification on the intermediate frequency signal, a local oscillation module connected to the control module and the up-conversion module and configured to provide a local oscillation signal for the up-conversion module and a clock signal for the system, and a power module.

Preferably, the multiband antenna and the external power amplifier module are equally divided into three bands of 0.2-2 GHz, 2-6 GHz and 6-18 GHz, wherein a circumferential antenna is adopted at 0.2-2 GHz, and ridge horn antennas are adopted at 2-6 GHz and 6-18 GHz.

Preferably, the multiband antenna is mounted on a reinforcing tripod, and the external power amplifier module is integrated into an independent chassis.

Preferably, the system further comprises a secondary power supply module for supplying power to the waveform generation module and the up-conversion excitation module, and a mobile alternating current power supply for supplying alternating current to the system when no commercial power is available.

(III) advantageous effects

Compared with the prior art, the radar signal source provided by the invention can generate a complex electromagnetic environment by simultaneously generating a plurality of radar signals in different forms, namely, by a multi-channel intermediate frequency signal generation technology, simultaneously generating intermediate frequency signals with independent and adjustable multiple radar parameters, and converting the intermediate frequency signals into signals in different frequency bands through up-conversion to form the complex electromagnetic environment.

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 system of the present invention;

FIG. 2 is a block diagram of the waveform generation module of FIG. 1 according to the present invention;

FIG. 3 is a schematic block diagram of a wideband digital transceiver board used in the signal generator of the present invention;

FIG. 4 is a schematic block diagram of a DDS FPGA with a cordic algorithm adopted by the digital frequency synthesis module of the present invention;

FIG. 5 is a schematic block diagram of the upconversion excitation module of FIG. 1 in accordance with the present invention;

fig. 6 is a schematic block diagram of the external power amplifier module shown in fig. 1 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 radar signal source comprises a main control computer, a waveform generation module, an up-conversion excitation module, an external power amplification module and a multiband antenna, wherein the waveform generation module is connected with the main control computer and used for synthesizing digital signals generated by multiple independent radar signal channels into analog intermediate-frequency signals, the up-conversion excitation module is connected with the waveform generation module and used for carrying out up-conversion excitation amplification on the analog intermediate-frequency signals, the external power amplification module is connected with the up-conversion excitation module and used for amplifying the signals, and the multiband antenna is directly connected with the up-conversion excitation module or connected with the external power amplification module and used for analog generation of radar signals.

The main control 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 radar parameter editing, man-machine interaction and the like.

The core algorithm that multichannel signal produced all realizes in the FPGA of waveform generation module, according to the functional requirement, designs 16 independent radar signal passageways altogether, and every signal generator can generate the radar signal of different forms according to the radar parameter, through ethernet interface, RS232 serial ports, and the host computer can realize the control to these 16 radar signal passageways.

As shown in fig. 2, the waveform generating module includes a control interface module for receiving radar parameters sent by the host computer, signal generators for generating digital signals of different forms according to the radar parameters, a digital frequency 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 radar parameters sent by the main control computer through an Ethernet interface and an 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.

As shown in fig. 3, 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. 4, the digital frequency synthesis module employs a DDS FPGA based on cordic algorithm. The FPGA generates intermediate frequency digital signals through a direct digital frequency synthesis technology, and has the advantages of high frequency resolution, high conversion speed, continuous phase and the like. The DDS is realized by a lookup table method in the prior art, but the size of a lookup table ROM for storing phase-amplitude conversion and the bit number of phase precision form an exponential relation, and when the precision requirement is high, a large-capacity ROM is needed, so that the high-precision and high-speed DDS cannot be designed by the lookup table method. When the cordic algorithm is adopted to realize the hyper-function, a multiplier is not needed, only a minimum lookup table is needed, and high-precision sine and cosine waveforms can be generated by simple shift and addition operation, so that the method is particularly suitable for FPGA realization.

As shown in fig. 5, the up-conversion excitation module includes a control module, an up-conversion module connected to the control module and used for performing up-conversion excitation amplification on the intermediate frequency signal, a local oscillator module connected to the control module and the up-conversion module and used for providing a local oscillator signal for the up-conversion module and a clock signal for the system, and a power module.

The multiband antenna and the external power amplifier module are equally divided into three wave bands of 0.2-2 GHz, 2-6 GHz and 6-18 GHz, wherein a circumferential antenna is adopted for 0.2-2 GHz, and ridge horn antennas are adopted for 2-6 GHz and 6-18 GHz. In the technical scheme, the band of 6-18 GHz is preferably selected.

The system considers two using modes, the excitation output is directly connected to the multiband antenna under the near-field distance environment, and the excitation output is further power amplified by the external power amplifier module and then connected to the multiband antenna under the far-field distance environment so as to increase the acting distance.

The multiband antenna is installed on the reinforcing tripod, and the external power amplifier module is integrated into the independent case. Wherein, the technical indexes of the 0.2-2 GHz power amplifier (room temperature 25 ℃, 50 ohm impedance, +48V +/-10%) are shown in the following table 1:

index parameter	Minimum value	Typical value	Maximum value	Unit of
					Frequency range	0.2	-	2	GHz
Gain of	40	-	-	dB
					Flatness of gain	-	±2.5	-	dB
Output saturation power	-	37	-	dBm
					Standing wave at input port	-	2.0	-	:1
Output port standing wave	-	2.0	-	:1
					Voltage of	-	48	-	V
Electric current	-	0.6		A

TABLE 1

The technical indexes of the 2-6 GHz power amplifier (room temperature 25 ℃, 50 ohm impedance, +48V +/-10%) are as shown in the following table 2:

TABLE 2

The technical indexes (room temperature 25 ℃, 50 ohm impedance, +48V +/-10%) of the 6-18 GHz power amplifier are shown in the following table:

index parameter	Minimum value	Typical value	Maximum value	Unit of
					Frequency range	6	-	18	GHz
Gain of	30	-	-	dB
					Flatness of gain	-	±2.5	-	dB
Output saturation power		37	-	dBm
					Input standing wave	-	2.0	-	:1
Output standing wave	-	2.0	-	:1
					Voltage of	-	12	-	V
Electric current	-	7.5		A

TABLE 3

The technical specifications of the multiband antenna are shown in table 4 below:

TABLE 4

The system also comprises a secondary power supply module used for supplying power to the waveform generation module and the up-conversion excitation module, and a mobile alternating current power supply used for supplying alternating current to the system when no commercial power is available. The mobile alternating current power supply adopts a BJC-1000W portable alternating current and direct current power supply.

Based on the radar signal source of the present application, a method for generating a multi-channel if signal for a radar signal source is provided, which includes 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 to generate analog intermediate frequency signals.

As shown in fig. 3, the signal generator works 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.

The method for mixing the broadband intermediate frequency signal with the local oscillator signal through the up-conversion excitation 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 first local oscillation signal of 23.8GHz and the second local oscillation signal of 22.35 GHz-40 GHz are both generated by the local oscillation module.

The up-conversion excitation module mixes the broadband intermediate frequency signal with the local oscillator signal and then divides the signals into signals of three wave bands of 0.2-2 GHz, 2-6 GHz and 6-18 GHz, and the signals of each wave band are filtered by a band-pass filter, digitally attenuated, amplified and finally subjected to switch filtering to suppress harmonic waves and then output to a transmitting channel. In the technical scheme, the band of 6-18 GHz is preferably selected.

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.