Radar target simulator based on CPCI interface DSP board

A C-band radar target simulator based on CPCI interface DSP board is proposed. Detection of echo simulation, using a combination of hardware and software. The target computer pre-sets and calculates the target data based on the radar operating parameters, and then loads the data into the hardware circuit. The hardware circuit synthesizes the radar echo signal in real time and outputs it. Real-time simulation of target echo signals in multiple complex modes such as phase encoding, linear frequency modulation, and nonlinear frequency modulation can be realized by using DSP/FPGA high-speed computing performance, direct digital synthesis (DDS) technology, and digital radio frequency storage (DRFM) technology. , to detect radar tracking accuracy, angular accuracy and other indicators.

1 function and system composition

The designed multi-target radar simulator is used for equipment debugging and function checking in conjunction with a certain type of broadband radar system. The simulator forms the analog target echo by delay, amplitude phase modulation and Doppler shift, and transmits it through the antenna or directly into the test radar system. The target echo signal includes information such as the distance, angle, velocity, radar cross-sectional area (RCS), and one-dimensional distance image of the target.

The overall system requirements are as follows: dual-channel output; frequency range is 5.2 to 5.8 GHz; narrowband instantaneous bandwidth is 10 MHz; wideband instantaneous bandwidth is 500 MHz; target number is 1 to 22; amplitude control range is 0 to 127 dB, quantization unit Not more than 0.5 dB; RCS amplitude control rate is 1μs, distance change amplitude is controlled by 1 ms; target delay time is 2~4 000μs; Doppler shift range is ±400 kHz; phase noise is not greater than -90dBc/Hz@1 kHz; The spurious level is not more than -55 dBc in narrowband; the spurious level is not more than -45 dBc in wideband; the distance simulation accuracy is ≤1.5 m; the Doppler analog accuracy is <1 Hz; the input power is -45 to +30 dBm; The maximum output power is 20 dBm.

The C-band radar target simulator consists of a microwave subsystem, a baseband subsystem, a broadband subsystem, a power control distribution component, and software, as shown in Figure 1. The microwave subsystem includes a receiving component, a transmitting component, a frequency source component, a power source, and the like. The baseband subsystem is mainly composed of a main control computer, a digital management unit (DMU), an interface control unit, a dual-channel programmable digital delay line (PD-DL), a clock generation and distribution circuit, an intermediate frequency modulation and demodulation component, and a power supply. The narrowband target simulation is mainly implemented by the baseband subsystem and the microwave subsystem.

Broadband target simulation is mainly realized by the baseband subsystem control broadband subsystem, as shown in Figure 2. The output is output with a narrowband target signal through a microwave subsystem. The power control distribution component performs functions such as control, distribution, protection, and indication of the system main power.