Millimeter Wave Passive Lord Array Detection System Signal Processing Algorithms

The active/passive millimeter wave detection system is a compound system of active mode and passive mode. The millimeter wave detector is working on active mode to search, recognize and track the target when the target is far away. The detector converts to passive mode when the distance of the target is equal to the setting value. In this mode, the detector continues tracking the target until identifying the center of the target exactly. In this paper, we study on this system with three channels, one is used to transmit wave and another two channels are used to receive wave, it is different from single channels as it can detect the location of two dimensional of the target accurately. We use the mode of FPGA combined with DSP to process signals, the main function of FPGA is detecting the distance of the target and generating saw-tooth wave, DSP is used to locking the center of the targets.Firstly, this paper describes the working theory of Radar detector. We use the XC3S50chip to generate a saw-tooth wave with a changing frequency and calculate the target’s distance according to the principle of fixing the different frequency in the active mode. It talks about the principle of selecting the parameter such as modulation period and modulation deviation of the system.Secondly, this paper describes the working theory of radiometer, and using the TMS320F2812chip to configure the target and identification the center of the target in the passive mode. Here, it talks about the working theory of radiometer with double channels and analyses process of the radiometer detecting the target.Finally, the algorithm of target recognition has been studied in this paper. At first, describing the theory of Correlation algorithm, and then making program with C language based on correlation theory; At last, making experience to validate the feasibility of using Correlation algorithm to recognize the radial center of the target based on millimeter active/passive compound detector. As the experiment data shown, the mode of FPGA combined with DSP can meet the requirement of high real-time, miniaturization and high speed signal process.