Research Of Millimeter-wave Frequency-scanning Antenna

With the development of the microwave technology, research focus in modern microwave technology has mostly focused on millimeter wave band, which has a richer spectrum resources. Research based on millimeter wave has covered communications, remote sensing, medical and other fields. Now, studies of millimeter-wave(MMW) technology on abroad is more advanced, a mass of products and millimeter-wave systems based on millimeter-wave technology has put into practical application. However, most domestic research of millimeter-wave technology mainly focus on 8mm band, but the technology of high frequencies wave-band in MMW includes 3mm, 2mm and even 1mm is developing slowly, which is not only because of its relevant theoretical research is not enough in-depth, also includes the design level of the domestic microwave processing technology can’t meet the requirements of practical application.MMW remote sensing detection technology which use electromagnetic wave reflection, refraction and other properties to measure the goal’s position, track, range and others has great value in weather, military and other fields applications. The project is on the background of national major scientific instruments and equipment development projects remote sensing detection application, designing a 3mm band frequency scanning antenna, which can be used in remote sensing detection field. The antenna is based on SIW, with the one-dimensional frequency scanning characteristic of the antenna, the target can be detected only by one MMW radiometer, which can avoid the error of radiometers’ inconsistencies, and also reduce the system costs.The paper introduces the basic principle of frequency scanning antenna, the design requirements of antenna structure parameters is given and proved the design of antenna feed network structure has the influence of the antenna frequency sweep characteristics. Giving the basic principle and design method of SIW, and proved that the SIW can be instead by equivalent di electric waveguide in the course of modeling antenna to realize the simplified modeling and improving the efficiency of antenna simulation optimization through theoretical analysis and software simulation.Proposing the theoretical analysis of the paper frequency scanning antenna, simulating and optimizing the performance of the antenna by HFSS software, and giving the explanation of the simulation results and parameter sele ction. The proposed antenna is a SIW 16-unit slot array frequency sweep antenna, the center frequency is 94 GHz, |S11|<-10 d B in 92GHz-99.5GHz, corresponding to the scanning angle is 15°-40°,|FSLL| <-10 d B, the 3d B beam width is less than 4°. The Gain is changing smoothly in the sweep frequency band, steady at 13.8d B-15.8d B. The radiation characteristic of the proposed ante nna can meet the demands of the project. Besides, the paper introduces a metal grid lens structure that can make the 3d B beam width of H plane radiation pattern decrease greatly, and realizing Gain enhancement about 3-4d B, which can improve the radiation characteristic of the antenna to satisfy the application requirements of some certain areas.