一种分段的超短波对数周期天线设计与实验OACSTPCD

The propagation mode of very high frequency(VHF)is mainly propagation over the line of sight,and this mode of propagation requires antennas with strong directivity and high gain.The log-periodic antenna is a kind of ultra-broadband medium gain antenna,which is very suitable for VHF communication.However,in the VHF band,the length of the conventional log-periodic antenna is relatively long,and its miniaturization is not high.In order to realize a miniaturized log-periodic antenna for VHF communication,a design scheme of segmented VHF log-periodic antenna is proposed in this paper.According to the application demand,the antenna length is reduced by segmentation design while satisfying the antenna gain,and the angle between the collection lines is adjusted to achieve antenna impedance matching.After the simulation design,the typical gain of the antenna in 30～70 MHz is greater than 8 dBi,and the length of the antenna is reduced to 7 m.The antenna is tested experimentally by the field test system based on the unmanned aerial vehicle(UAV)flight platform.The test results show that the voltage standing wave ratio(VSWR)of the antenna is less than 1.5 in the operating frequency range,and the radiation characteristics of the test and simulation are basically consistent.The proposed antenna has the characteristics of wide bandwidth,high gain and simple structure,which can meet the demand of VHF antenna in practical scenarios.