Research And Design On Target Array Wideband Antenna In RF Simulation System

As the rapid development of RF simulation technology, antenna of the target array in RF simulation system is becoming smaller, wide-band and multi-functional. Thus, it's of great significance to investigate the miniature and wideband antenna which is suitable for RF simulation system. According to the requirements of RF simulation system on antenna design, the wideband circularly polarized planar Archimedes antenna, and the wideband dual-polarized antenna have been investigated and designed.The main work and associated novelty of this dissertation includes:1. A planar Archimedes antenna operating between 0.4 to 3GHz is investigated and designed. The dual-arm Archimedes spirals with identical arm width and clearance act as radiation units of the antenna, which are self-compensative and can implement impedance matching in wideband. The radiation units are fed through a tapered microstrip balun, and its large vertical dimension has been remedied, the solution is to replace the straight microstrip balun with a curved one. Besides, a reflective back cavity is designed and loaded backside so as to make the antenna unidirectional. The simulation shows that the VSWR stays lower than 2 within the range of 0.4~3GHz, and no beam splitting in radiation pattern, moreover, the antenna gain stays stable. At last, the Archimedes spiral antenna has been fabricated and tested, and the results show good consistency compared to the simulation.2. A wideband dual-polarized circular horn antenna operating between 0.4~2GHz is investigated and designed. The four-ridge waveguide dual-feeding technique is utilized to obtain wide band and dual-polarization. The antenna is truncated according to requirements, and arc slices are added on the cross ridge without any change of antenna size and shape so that the antenna size is reduced without the loss of antenna performance. The simulation shows that within the bandwidth from 0.4 to 2GHz, the VSWR of either port is lower than 3, and isolation between two ports is better than 30 d B, and no beam splitting in radiation pattern, which implies good radiation performance. Afterwards, the antenna has been fabricated and tested, and the results show good consistency compared to the simulation.3. A wideband dual-polarized circular horn antenna operating between 20~50GHz is investigated and designed. Similar to the previous antenna, the wide band and dual-polarization are obtained the same way, and the problem that antenna gain cannot meet the desired value is also remedied by rising horn section length while keeping the ridge length fixed. The simulation shows that within the bandwidth from 20 to 50 GHz, the VSWR of either port is less than 2.5, and isolation between two ports is better than 20 d B, what's more, the antenna gain is greater than 20 d Bi, except only a few frequency, of which antenna gain is greater than 18 d Bi. Eventually, the antenna has been fabricated and tested, and the results meet the index requirements.