Simulation Of Millimeter Wave Short-range Detecting System

The simulation of millimeter wave short-range detecting system, taking millimeter wave as a carrier, is a closed-loop behavior functional simulation constructed by using ADS, Matlab and LabVIEW. The simulation is based on different continuous millimeter wave short-range detecting systems and corresponding target model, and it has some characteristics such as verifiability of node data and nonlinear analysis of module devices. As a way of the digital simulation, compared with conventional physical simulation and Hardware-In-the-Loop one at home and abroad, the simulation of millimeter wave short-range detecting system can not only comprehensively utilize advantages of the software (i.e., ADS, Matlab and LabVIEW), but also embed relevant measurement instrument and device module. This can improve assessment ability of short-rang detecting system, reduce burden of test personnel, and economizes the cost of measurement.The paper focuses on simulation of continuous millimeter wave short-rang detecting system with different systems, and its main works and research results are as follows:1. The general framework of the millimeter wave short-range detecting system simulation is studied. Firstly, we present a hybrid simulation method and discuss selection of parameters after analyzing the shortcomings of existing simulation platforms (i.e., ADS, Matlab and LabVIEW) in millimeter wave short-range detecting system. The hybrid simulation is mainly based on ADS with the help of Matlab and LabVIEW. Then, we divide a target into small polygon elements according to the principle of near-field to far-field conversion of the target by PO, PTD and SBR to predict high frequency scattering characters of near-field target, and simultaneously analyze antenna pattern influence on above high frequency near-field scattering. Lastly, we analyze the detector signal transmission power attenuation in supersonic velocity exterior ballistics as a result of the raised radome wall temperature due to shock wave and the influence of actual bad surrounding which supersonic radome works in. on short-range system simulation2. Under the system of Doppler millimeter wave type, the simulation of continuous wave short-range detecting system is studied. Firstly, we built up ADS simulation schematic of the Doppler millimeter wave detecting system after analyzing transmitter, receiver, antenna directional graph and Doppler target model of detecting system, and test feasibility of the system by a moving small target. Then, taking a trajectory helicopter as an example, we model it by UG5.0, divide the helicopter into plane elements byλ/16 spacing interval, apply high frequency hybrid method to computation of helicopter's near-field RCS, construct Doppler echo signal model of the helicopter, utilize Matlab_M to construct an embeddable ADS target model after compensating relevant parameters of carrier and detector, and build up behavior level simulation chain of millimeter wave short-range detecting system by combination of the above target model and detector one. Finally, we do time-frequency processing for a mixer's output signal by setting node probe at the mixer's output line and using embeddable LabVIEW virtual instrument software, and get time-frequency spectrum diagram of the helicopter.3. Under the system of linear frequency modulation (LFM) millimeter wave type, the simulation of continuous wave short-range detecting system is studied. Firstly, distance measurement principle of the detecting system and parameters of system model are analyzed constructe an ADS behavioral level function simulation model. We demonstrate correctness of the detecting system model by self-checking of the system. In addition, taking a trajectory helicopter as an example, we construct target model of it, and embed the target model into simulation of LFMCW frequency modulation detecting system. We utilize LabVIEW to analyze time-domain, frequency-domain and STFT of mixer's output signal. Analysis result shows that the mixer's different frequency signal not only truly reflects the apparent distance change between detector and target, but also depicts the helicopter's time-frequency spectrum diagram in detail. This improves intelligence of simulation.4. Under the system of pseudo random code phase modulation combined with periodic square type, the simulation of continuous wave short-range detecting system is studied. Firstly, ranging and velocity measurement performance of ambiguity function of the detecting system are analyzed. We also discuss the selection of some parameters such as code width and rectangular wave period of the detecting system, and construct ADS simulation model of transmitter, receiver and target model simultaneously. A simple example is self-checked to verify feasibility of the system. Then, taking a trajectory cruise missile as an example, we utilize LabVIEW to analyze time-domain, frequency-domain and STFT of mixer's output signal. Analysis result shows that the method not only has a good performance of ranging, velocity measurement and anti-interference, but also has intuitive characteristic of graphic analysis. Hence it has great prospect in engineering practice.5. Under the system of conical scanning active and passive millimeter wave type, the simulation of continuous wave short-range detecting system is studied. On the basis of the least second detection principle and characteristics of active frequency modulation ranging and passive radial direction location, we firstly construct ADS behavior level simulation of active and passive detecting system and discuss some key parameters of three-beam antennas such as rotating velocity, dropping velocity and internal angles. Then, we use LabVIEW to simulate detector signal at certain height. Corresponding result shows that this method not only obtains accurate distance parameter, but also greatly improves precision of target radial positioning, which has important significance in engineer practice.