Research On X-band Frequency Selective Surface And Transmission Array Antenna

Both Frequency Selective Surface(FSS)and transmission array antennas must consider the transmission performance of the unit when designing.Broadening the bandwidth is a difficult problem to be solved in the design of both.Both have very important application value in the military and civilian fields.As a spatial filter,FSS mainly uses its ability to selectively transmit electromagnetic waves to make a radome to help the radar carrier achieve the "stealth" effect;the transmission array antenna is mainly used high-gain antenna to cope with longdistance communication or detection.This article focuses on the design and analysis of frequency selective surface and transmission array antenna.The main contents are as follows:1.Introduced the working principle and related technical indicators of the frequency selection surface;analyzed the transmission performance of different types of unit structures;studied the factors affecting the frequency selection surface;commonly used methods for analyzing the frequency selection surface and made a summary about the steps of designing the frequency selection surface.2.A double-layer structure of X-band band-pass broadband frequency selection surface is designed.The unit is a combination structure of a square ring and a square patch.The two-layer structure is adopted to achieve broadband expansion,and the relative working bandwidth reaches 48.5%;the resonance principle of the FSS unit is analyzed by the equivalent circuit method;FSS has very good polarization stability.At the same time,when the incident angle is in the range of 0°-45°,FSS has good angular stability.After testing the designed FSS,the test results are consistent with the simulation results,indicating that the FSS meets the expected design requirements.3.Introduced the basic concept of the transmission array antenna and the theoretical basis of designing the transmission array antenna;researched the elements of the transmission array antenna.4.A broadband transmission array antenna of X band is designed.The unit adopts a fourlayer structure and has a phase shift range of more than 360° in the designed working frequency band.A four-ridge speaker with a center frequency of 10 GHz is designed as a feed source.The maximum gain of the horn is 11.4d Bi;based on the unit and the feed,the transmission array antenna is designed,the antenna array is 187mm*187mm,the focal diameter ratio is 0.31,the maximum gain of the antenna obtained by simulation is 20.3d B,and the relative bandwidth reaches 35.1%;The transmission array antenna was processed and tested in a microwave anechoic chamber.The test results and the simulation results are consistent,and the antenna design meets the requirements.