A Rotatable Frequency- and Pattern-Reconfigurable Antenna with a Wide Tunable Bandwidth

Abstract

ABSTRACT The proposed design introduces a novel rotatable frequency- and pattern-reconfigurable antenna, characterised by its wide tunable bandwidth. The proposed design contains a fixed feeding part and a rotatable part. The rotatable part consists of three array antennas. Each of the three array antennas is formed of two elements loaded with varactors. The working frequency of the design is able to be changed through adjusting the varactors’ value and employing the rotatable action within the circular configuration. Design benefits from both independent bias voltages, offering pattern reconfigurability. To attain this function, a phase shift is introduced between the two elements of the operating array antenna. Utilizing the quasi-Yagi antenna mechanism enhances the gain. In the proposed configuration, a measured continuously tunable frequency bandwidth of 37.4% is observed, spanning from 2.65 GHz to 3.87 GHz. Additionally, it achieves maximum beam-tunable angles ranging from −40° to +44° covering the broadside. The scanning gain variation of the proposed design is within 4 dB over the entire band. To validate the proposed method, we present both simulated and measured results.