CN110045343B - A broadband multi-channel radar signal comprehensive simulation system and its working method - Google Patents

Abstract

The invention discloses a broadband multi-path radar signal comprehensive simulation system and a working method thereof.A waveform is customized in a waveform generator by embedded software, an initial signal frequency is formed, the initial signal frequency is respectively synthesized in two paths of synthesizers after multi-path up-conversion and up-conversion, the signal power is amplified by a broadband power amplifier and is transmitted to an antenna through a transmission line to be radiated. The control equipment controls the host machine to work according to a selected program through computer operation software, can output various radar waveforms in a single path, and can also output radar signals in multiple paths and multiple waveforms. Each path of radar signal is controlled by a switch to output or not, and conditions are provided for sequential emission of combat simulation. The broadband circuit is a multi-path radar signal analog simulation system, each path of radar signal can be provided with waveform, repetition frequency, working frequency and output on-off, the effect is vivid, the practical range is wide, and the problems of comprehensive analog simulation of radar signals and radiation of full-band radio frequency signals in the prior art are effectively solved.

Description

A broadband multi-channel radar signal comprehensive simulation system and its working method

technical field

The invention belongs to the field of electronic information engineering, and in particular relates to a comprehensive simulation system of a broadband multi-channel radar signal and a working method thereof.

Background technique

In complex electromagnetic environment, radar signal is one of the most important radio signals. This is due to the wide frequency range of radar signals, complex signal waveforms, diverse working modes, large radiated power, and intelligent frequency adaptive management. The most important thing in simulating a complex electromagnetic environment is to solve the problem of simulating various radar signals, and the core technology of radar signals is the diversification of waveforms and the rapidity of frequency changes. The radar signal consists of both continuous waves and pulse waves. The preparation of pulse wave signals is complicated. Under the pulse compression system, there are dozens of single carrier frequency, linear frequency modulation, nonlinear frequency modulation, digital coding, and even quantum key coding, and there are ordinary mode, PD mode and CW/ FM mode, etc., and the arrangement of pulse groups and repetition frequencies is ever-changing, resulting in multiple characteristics of radar signals. In constructing various devices that simulate the electromagnetic environment, it is a big problem to solve the comprehensive simulation of radar signals.

SUMMARY OF THE INVENTION

The purpose of the invention is to provide a broadband multi-channel radar signal comprehensive simulation system and a working method thereof, which effectively solve the problems of the existing technology in the comprehensive simulation simulation of radar signals and the radiation of full-band radio frequency signals.

Technical solution: A comprehensive simulation system for broadband multi-channel radar signals, which is characterized by comprising: a mode selection module, a waveform generator electrically connected to the mode selection module, and a multiplexer electrically connected to the waveform generator. a frequency converter, a signal combiner electrically connected to the up-converter, a wideband power amplifier electrically connected to the signal combiner, a selection switch electrically connected to the wideband power amplifier, and a The switch is electrically connected to the broadband antenna; the mode selection module and the selection switch are connected by two-way communication through the integrated control system; the waveform generator and the up-converter are connected by two-way communication through the frequency source.

In a further embodiment, the mode selection module, the waveform generator, the up-converter, the signal synthesizer, the broadband power amplifier, and the selection switch constitute a host; the host and the computer are connected in communication, and the connection method includes communication cable, encrypted radio; the mode selection module includes two candidate modes, namely normal mode and actual combat mode; the waveform generator includes eight options, namely continuous wave, intrapulse linear frequency modulation, nonlinear frequency modulation, Coded pulses, PD patterns, groups of pulses, fixed repetition frequency, and variable repetition repetition frequency. In normal mode, various radar waveforms, repetition frequencies, and radar RF frequencies are selected and customized according to the user's wishes, and each channel outputs radiation signals according to the selection; Short-range fire control and warhead guidance radar work in sequence to transmit RF radar signals.

In a further embodiment, the output band of the up-converter intercepts two bands from the P band to the Ku band, and the band bandwidth is ten percent. This band has little interference, strong penetration, and is not easily reflected by the ionosphere.

In a further embodiment, the frequency source generates a chirp signal and a frequency hopping signal through a direct digital frequency synthesizer. The direct digital frequency synthesizer includes a phase accumulator, a sine look-up table electrically connected to the phase accumulator, a digital-to-analog converter electrically connected to the sine look-up table, and the digital-to-analog converter Electrically connected low-pass filter. Compared with traditional frequency synthesizers, direct digital frequency synthesizers have the advantages of low cost, low power consumption, high resolution and fast conversion time, and are suitable for radar detection.

A working method of a broadband multi-channel radar signal comprehensive simulation system, which is characterized by comprising the following steps:

The first step is to start the equipment, and establish two-way communication between the integrated control system, the mode selection module and the selection switch;

The second step, the mode selection module is controlled to start, and switches between the normal mode and the actual combat mode according to the instructions of the operator;

The third step, the waveform generator is started under the control of the mode selection module, and the parameters are set, including the signal setting, the repetition frequency setting, and the working frequency setting;

The fourth step, the waveform generator generates the basic radar waveform of 15Mhz, and divides it into several signals by the power divider and sends it to the up-converter;

The fifth step, the up-converter mixes the basic radar waveform and the "frequency source" signal to form various radio frequency signals, which are sent to the signal synthesizer through their respective switches;

The sixth step, the RF signal synthesized by the signal synthesizer is amplified and synthesized by a high and low broadband power amplifier to synthesize a new RF signal;

In the seventh step, the synthesized new radio frequency signal is radiated to the space by the high and low frequency band antennas respectively.

In a further embodiment, the normal mode is to arbitrarily set the opening sequence of the radar frequency bands; the actual combat mode determines that the radio frequency signals are turned on in sequence, including the P and L bands for remote warning, the L and S bands for combat guidance, and the C for fire control radar. , X-band, and Ku-band for warhead homing guidance. Different frequency bands are used according to different functions to prevent interference between functions and ensure the stability of operation.

In a further embodiment, the signal arrangement includes both continuous waves and pulse waves, the pulse waves include conventional pulses and pulse compression, the conventional pulses are single-frequency pulses, and the pulse compression includes FM and coding pulse; the FM is divided into intra-pulse linear frequency modulation and nonlinear frequency modulation; the signal setting also includes the selection of pulse width and pulse repetition frequency of the pulse wave; the single carrier frequency pulse, intra-pulse linear frequency modulation, non-linear frequency modulation The chirp and coded pulses are combined to form a pulse group. Different pulse widths are suitable for a predetermined range of repetition frequencies, otherwise a "range blur" is created.

In a further embodiment, the repetition frequency setting includes selection of fixed repetition frequency, repetition frequency jittering, and repetition frequency staggering; and the repetition frequency setting is fed back to the pulse wave.

In a further embodiment, the frequency source is a multi-channel output signal source, and the operating frequency setting may be a fixed frequency or a frequency agile frequency setting for the frequency source.

Beneficial effects: The present invention relates to a comprehensive simulation system of wideband multi-channel radar signals and a working method thereof. By using computer technology, various radar signals are arranged in a centralized manner, and dozens of radar waveforms are simulated. The grouping can be adjusted and combined arbitrarily. After modulation and frequency conversion, a 15MHz basic radar signal is formed, which is distributed to the analog branch of the multi-channel radar RF signal by the multi-channel power divider. The frequency source is the only coherent source of this equipment. It is characterized by the use of DDS direct frequency synthesis technology to achieve high-speed output of any frequency signal. The step frequency change of DDS provides conditions for high-speed frequency agility within the frequency band. The integrated control system realizes intelligent control of the selection of radar signals, the customization of radar frequencies, the on-off of various radio frequency signals, and the conversion of normal and actual combat modes. The invention solves the problem of omnipotent waveform simulation and multiple frequency simulation, and its waveform, operating frequency and repetition frequency basically cover the technical characteristics of conventional radars at home and abroad, and provides conditions for signal analysis, electromagnetic environment investigation and training, and the like. At the same time, the broadband circuit of the present invention is a multi-channel radar signal simulation system, which has the characteristics of setting waveform, repetition frequency, operating frequency and output on-off for each radar signal, with realistic effect and wide practical range.

Description of drawings

Fig. 1 is the composition block diagram of the present invention.

FIG. 2 is a schematic diagram of the working process of the present invention.

FIG. 3 is a block diagram of the composition of the host in the present invention.

Fig. 4 is the working principle diagram of the direct digital frequency synthesizer in the present invention.

FIG. 5 is a band information table involved in the present invention.

Detailed ways

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without one or more of these details. In other instances, some technical features known in the art have not been described in order to avoid obscuring the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

As shown in Figure 1, the present invention mainly includes a host, an antenna and a control device (computer). The host is the core component, and its composition is shown in Figure 3. Various waveforms are customized in the waveform generator by the embedded software, and the initial signal frequency is formed. After multi-channel conversion and frequency upscaling, the two-channel synthesizers are synthesized respectively, and the signal power is amplified by the broadband power amplifier and sent to the antenna through the transmission line. radiate out. The control device is controlled by the computer operating software to control the host to work according to the selected program, which can output a single channel of various radar waveforms, and can also output multiple channels of multiple waveform radar signals. Each radar signal is controlled by the switch to output or not, which provides conditions for the sequential launch of combat simulation. The output requirements of the signal are configured by the computer, and various basic radar waveforms are generated in the host for output selection. The up-converter upconverts the basic radar signal to a typical radar operating frequency, and then the power is amplified by the power amplifier. The invention can simulate 16 kinds of radar frequencies and various radar waveforms, basically covering the signal modes of today's main battle radars, and can also add various interference information according to requirements to build a realistic radar electromagnetic environment. The invention uses software to set a simple combat mode, and sets the startup sequence of radars of different programs according to the long-range early warning-medium-long-range alert-guidance-guidance process, which has certain battlefield situation significance. At the same time, the transmission power of the system is small, and the antenna has the function of directional radiation, which does not affect the normal operation of other electronic equipment.

As shown in Figure 2, the present invention includes a mode selection module, a waveform generator, an up-converter, a signal synthesizer, a wideband power amplifier, a selection switch, a wideband antenna, an integrated control system, and a frequency source. The waveform generator is electrically connected to the mode selection module, the up-converter has multiple channels and is electrically connected to the waveform generator, and the signal synthesizer is electrically connected to the up-converter , the wideband power amplifier is electrically connected with the signal combiner, the selection switch is electrically connected with the wideband power amplifier, the wideband antenna is electrically connected with the selection switch, the mode selection module and the selection switch are electrically connected The switches are connected by two-way communication through the integrated control system; the waveform generator and the up-converter are connected by two-way communication through the frequency source.

As a preferred solution, the mode selection module, the waveform generator, the up-converter, the signal synthesizer, the broadband power amplifier, and the selection switch constitute a host; the host and the computer are connected for communication, and the connection method includes a communication cable , encrypted radio; the mode selection module includes two modes to be selected, namely normal mode and actual combat mode; the waveform generator includes eight options, namely continuous wave, intrapulse linear frequency modulation, nonlinear frequency modulation, coded pulse , PD mode, pulse group, fixed frequency of repetition frequency, and variable repetition frequency of repetition frequency.

As a preferred solution, the output band of the up-converter intercepts two sections from the P-band to the Ku-band, and the frequency band bandwidth is ten percent; the frequency source generates a linear frequency modulation signal through a direct digital frequency synthesizer and frequency hopping signal. The direct digital frequency synthesizer includes a phase accumulator, a sine look-up table electrically connected to the phase accumulator, a digital-to-analog converter electrically connected to the sine look-up table, and the digital-to-analog converter Electrically connected low-pass filter.

The working process of the present invention is described in detail below:

The invention is a two-segment wideband radar signal simulation simulation system from P-band to KU-band. After the equipment is turned on, the integrated control system outputs control signals. First, select the radar signal simulation mode, that is, the "normal/actual combat" mode. The "actual combat mode" determines that the RF signal is turned on in sequence, that is, the remote warning P, L, the combat guidance L, S, the fire control radar is turned on C, X, and the warhead homing guidance Ku; "Normal mode" is to set the open sequence of radar bands arbitrarily. When working normally, parameter binding should be performed. First, set the parameters of the waveform generator, including signal setting and repetition frequency setting. There are two types of signal settings: "continuous wave" and "pulse wave". There are two kinds of "pulse wave": conventional pulse and pulse compression. The conventional pulse is a single carrier frequency pulse, and the pulse compression is divided into FM (LFM/NLFM) and encoded pulse (two-phase code, four-phase code). FM is divided into pulse linear frequency modulation, and nonlinear frequency modulation. Pulse selection also includes the selection of pulse width and pulse repetition frequency. Different pulse widths are suitable for a certain range of repetition frequencies, otherwise "distance ambiguity" will be formed. In "Repetition setting", you can select "Fixed Repetition", "Repetitive Jitter" and "Repetitive Staggered" according to your needs. When "Pulse Group" is selected, various pulses can be combined arbitrarily to form combined pulses. "PD mode" is a high repetition frequency Doppler detection mode. After the signal waveform is determined, the frequency is up-converted to the 15MHz basic radar waveform, and divided into several channels by the power divider and sent to the frequency converters on each channel. The up-converter mixes the basic radar waveform with the "frequency source" signal to form various RF signals, which are sent to the synthesizer through their respective switches. In this scheme, P, L and S are mixed into a low-frequency branch, and C, X, and Ku are mixed into a high-frequency branch, and the RF signals are amplified and synthesized by the high and low broadband power amplifiers respectively. The synthesized radio frequency signal is radiated into space by the high and low frequency band antennas respectively. "Working Frequency Setting" can be fixed frequency for "Frequency Source" or "Agile Frequency", and "Frequency Source" is a multi-channel output signal source.

More specifically, "mode selection" generally refers to "normal mode" and "actual combat mode". In the "normal mode", various radar waveforms, repetition frequencies, and radar RF frequencies are selected and customized according to the user's wishes, and each channel outputs radiation signals according to the selection; in the "actual combat mode", the radar work is to simulate wartime from long-range alert, medium and near The radio frequency radar signal is transmitted in sequence by the long-range guidance, medium and short-range fire control and warhead guidance radar work. "Multi-channel frequency conversion" is the sum of all conventional radar frequencies. According to international radio frequency division, there are dozens of frequency bands from HF to Ku band respectively determined as "radiolocation", the present invention grabs 20 kinds of typical frequency bands for analog video, and the bandwidth of each frequency band is 10%. "Signal synthesis" synthesizes the signals sent by multiple power amplifiers into one channel and sends it to the power amplifier for amplification. Considering the bandwidth limitation of the power amplifier and the radiating antenna, the signal synthesis can be divided into several sections, which are amplified and output by different broadband power amplifiers, and provided to the antennas of different frequency bands to radiate into space. "Broadband power amplifier" is a branch signal power amplifier sent by signal synthesis, which can be one channel or multiple channels. The power size can be customized as needed. The "selector switch" is controlled by the "integrated control system" to selectively turn on/off each RF signal. The "broadband antenna" radiates the RF signal from the switch into space. "Frequency source" is the coherent source of the equipment. It adopts DDS direct frequency synthesis technology and has the characteristics of fast frequency response, step sweep and multi-frequency output. The "integrated control system" is the intelligent control center of the equipment, so the control selection signals are all sent out by it.

The invention uses computer technology to centrally arrange various radar signals and simulate dozens of radar waveforms. The pulse width, pulse repetition frequency, pulse grouping, etc. can be adjusted and combined arbitrarily. After modulation and frequency conversion, a 15MHz basic radar signal is formed. The multi-channel power divider is distributed to the analog branch of the multi-channel radar RF signal. The frequency source is the only coherent source of this equipment. It is characterized by the use of DDS direct frequency synthesis technology to achieve high-speed output of any frequency signal. The step frequency change of DDS provides conditions for high-speed frequency agility within the frequency band. The radar radio frequency pulse signals formed by mixing various radio frequency signals output by the frequency source with the basic radar signals sent by the waveform generator are amplified in the power amplifiers of each frequency band, respectively outputting high-power radio frequency signals with different frequencies. The synthesizer synthesizes all the way, and radiates to the space through the broadband antenna, and completes the simulation process of the radar radio frequency signal. The continuous wave radar signal simulation provides the selected frequency signal directly from the frequency source, and outputs it through the radio frequency power amplifier. The integrated control system realizes intelligent control of the selection of radar signals, the customization of radar frequencies, the on-off of various radio frequency signals, and the conversion of normal and actual combat modes.

It is worth mentioning that in the present invention, the frequency source generates the linear frequency modulation signal and the frequency hopping signal through the direct digital frequency synthesizer. The specific working process of the direct digital frequency synthesizer is as follows: the digital waveform forms an analog waveform through a digital-to-analog converter; the frequency of the output waveform is changed by changing the clock frequency of the sine look-up table; the frequency of the output signal is changed by changing the addressing step size , the digital waveform passes through the sine look-up table, and the phase increment is accumulated by the phase accumulator. The digital-to-analog converter outputs the ladder waveform, which becomes a qualified analog waveform through a low-pass filter, and finally outputs.

As mentioned above, although the present invention has been shown and described with reference to specific preferred embodiments, this should not be construed as limiting the invention itself. Various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims (9)

1. A working method of a broadband multi-path radar signal comprehensive simulation system is characterized by comprising the following steps:

the comprehensive simulation system for the broadband multipath radar signals comprises:

the broadband power amplifier comprises a mode selection module, a waveform generator electrically connected with the mode selection module, a plurality of upper frequency converters electrically connected with the waveform generator, a signal synthesizer electrically connected with the upper frequency converters, a broadband power amplifier electrically connected with the signal synthesizer, a selection switch electrically connected with the broadband power amplifier, and a broadband antenna electrically connected with the selection switch; the mode selection module is in bidirectional communication connection with the selection switch through the comprehensive control system; the waveform generator and the upper frequency converter are in bidirectional communication connection through a frequency source;

the working method comprises the following steps:

s1, starting the device, and establishing two-way communication between the comprehensive control system and the mode selection module and the selection switch;

s2, the mode selection module is controlled to start, and the mode is switched between a normal mode and an actual combat mode according to the instruction of an operator;

s3, the waveform generator is controlled and started by the mode selection module to set parameters, including signal setting, repetition frequency setting and working frequency setting;

s4, generating a basic radar waveform of 15Mhz by a waveform generator, dividing the basic radar waveform into a plurality of paths of signals by a power divider and sending the signals to an upper frequency converter;

s5, the up-converter mixes the basic radar waveform with the frequency source signal to form each path of radio frequency signal, and the radio frequency signal is sent to the signal synthesizer through each switch;

s6, amplifying and synthesizing the radio frequency signals synthesized by the signal synthesizer into new radio frequency signals by a high-low two-path broadband power amplifier;

and S7, radiating the synthesized new radio frequency signals to the space by the high-low band antenna respectively.

2. The operating method of the broadband multi-path radar signal comprehensive simulation system according to claim 1, wherein: the mode selection module, the waveform generator, the upper frequency converter, the signal synthesizer, the broadband power amplifier and the selection switch form a host; the host computer is in communication connection with the computer in a mode of communication cables and encrypted radio; the mode selection module comprises two modes to be selected, namely a normal mode and an actual combat mode; the waveform generator includes eight options, continuous wave, intra-pulse chirp, non-chirp, coded pulse, PD pattern, pulse group, fixed frequency of repetition frequency, and variable repetition frequency of repetition frequency.

3. The operating method of the broadband multi-path radar signal comprehensive simulation system according to claim 1, wherein: the output waveband of the upper frequency converter intercepts two sections from the P waveband to the Ku waveband, and the bandwidth of the waveband is ten percent.

4. The operating method of the broadband multi-path radar signal comprehensive simulation system according to claim 1, wherein: the frequency source generates a chirp signal and a frequency hopping signal through a direct digital frequency synthesizer.

5. The operating method of the broadband multi-path radar signal comprehensive simulation system according to claim 4, wherein: the direct digital frequency synthesizer comprises a phase accumulator, a sine lookup table electrically connected with the phase accumulator, a digital-to-analog converter electrically connected with the sine lookup table, and a low-pass filter electrically connected with the digital-to-analog converter.

6. The operating method of the broadband multi-path radar signal comprehensive simulation system according to claim 1, wherein: the normal mode is the opening sequence of the radar frequency band which is set arbitrarily; the actual combat mode determines that radio frequency signals are opened in sequence and comprises a remote warning P, L waveband, a combat guidance L, S waveband, a fire control radar startup C, X waveband and a warhead seeking guidance Ku waveband.

7. The operating method of the broadband multi-path radar signal comprehensive simulation system according to claim 1, wherein: the signal setting comprises two types of continuous waves and pulse waves, wherein the pulse waves comprise two types of conventional pulses and pulse compression, the conventional pulses are single carrier frequency pulses, and the pulse compression comprises FM and encoding pulses; the FM is divided into intra-pulse linear frequency modulation and nonlinear frequency modulation; the signal setting also comprises the selection of the pulse width and the pulse repetition frequency of the pulse wave; the single carrier frequency pulse, the intra-pulse linear frequency modulation, the non-linear frequency modulation and the coding pulse are combined to form a pulse group.

8. The operating method of the broadband multi-path radar signal comprehensive simulation system according to claim 7, wherein: the repetition frequency setting comprises selection of fixed repetition frequency, repetition frequency jitter and repetition frequency spread; the repetition frequency sets a positive feedback to the pulse wave.

9. The operating method of the broadband multi-path radar signal comprehensive simulation system according to claim 1, wherein: the frequency source is a multi-channel output signal source, and the working frequency setting can be fixed frequency or frequency agility aiming at the frequency source.

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