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

Abstract

In 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.

Analysis of Radiation Characteristics of Compressed V-shape Dipole Antenna

“…To complete the primary task of the near-field communication system in the tilted state of the surface unmanned boat, it is necessary to design a device that can maintain its good omnidirectionality in the far-field even when the antenna is tilted on the hull, and ensure that it can still transmit(receive) a more accurate signal to(from) the far-field when tilted at multiple angles. [4] Figure 1: The working state of a surface unmanned craft equipped with a traditional whip antenna on a flowing sea Combining the practical requirements of short-range maritime communication, a compressed V-shape dipole antenna in the VHF band is designed [5] , which provides a realistic basis for single-point communication of surface unmanned boats in complex sea conditions, and also provides a reference for sea-to-air communication under high sea conditions. The VHF frequency band communication not only guarantees the maritime wireless communication rate, but also enables the receiving target to obtain a better signal-to-noise ratio.…”