A Wideband Tightly Coupled Array for Omnidirectional Pattern Synthesis

Abstract

This work presents the design of a wideband circular tightly coupled array for omnidirectional pattern generation. The proposed array works over an 8:1 bandwidth, providing very high performance in terms of active reflection coefficient, realized gain, and omnidirectional patterns with reduced ripples. The array is composed of 32 low-profile, self-complementary, bow-tie elements displaced around a metallic mast. The capacitive coupling between neighbouring elements and the implementation of a properly designed frequency selective surface allow for increasing the electrical length of each antenna while compensating for the inductive effect of the metallic mast, according to the tightly coupled and connected arrays theory. A cover layer is then inserted to improve the average gain on the azimuthal plane. Time-domain simulation results confirm the validity of the proposed approach and implementation.