Switchable design of a frequency reconfigurable broadband whip antenna in high frequency

Abstract

AbstractIn this paper, the antenna reconfigurable technology is used to redesign a whip antenna in different sub-bands of high frequency (HF). According to the electrical characteristics of the antenna, on the one hand, two different radiation whip heights are designed to solve the problem of pattern up-warping in the high-frequency band; on the other hand, a common upper loading network and several different adjusting inductors and matching networks are designed for each sub-band to achieve high gain and efficiency when keeping good voltage standing wave ratio (VSWR) characteristics. Five sub-bands of the 10-m HF whip antenna are reconfigured through the actual selection of radiation height, adjusting inductance, and matching network by radio frequency (RF) switch. The antenna load and matching network are optimized by grasshopper optimization algorithm (GOA), and integrated into the antenna body by using the printed circuit technology. The scaled prototype of 1 m frequency reconfigurable antenna is manufactured and tested, which shows that the VSWR is all <3 with an average value of 2.14; the gain is all >−2.5 dB with an average value of 3.90 dB; the efficiency is all >18.2% with an average value of 71.59%, and the patterns all keep horizontal omnidirectional without the phenomenon of up-warping.