A Wideband CPW-Fed Annular Ring Patch Antenna Design for Sub-Terahertz Applications

Abstract

This paper presents a compact coplanar waveguide (CPW)-fed annular ring antenna designed for sub-terahertz applications with wideband performance. The antenna has a circular ring radiator with a central circular slot and is fed by a vertically oriented CPW line connected at the bottom center of the ring, in addition to two symmetrical rectangular ground planes on each side. The structure is built on a polyimide substrate with a relative permittivity of 3.5. The overall size is 600 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{\mu} \mathbf{m} \times \mathbf{6 0 0} \boldsymbol{\mu} \mathbf{m} \times 75\mu\mathrm{m}$</tex>. The antenna operates over a broad impedance bandwidth ranging from 0.17 THz to 1 THz. It also achieves radiation efficiency above 85 % throughout this range and reaches a peak gain of 7.83 dBi at 1 THz. Thanks to its wide bandwidth, compact size, and efficient performance, the antenna is well suited for use in sub-terahertz high-speed systems.