A Novel Broadband Stacked Annular-Ring Antenna With Air Hole Integrated in Substrate

Abstract

This paper presents a circular polarization (CP) stacked annular-ring microstrip antenna (ARMSA) with a wide bandwidth and low profile. In this design, the two-layer annular ring excited by a single probe obtains a wide bandwidth by drilling an air hole in the substrate. The antenna profile decreases due to the combination of the single-fed structure and the air hole integrated into the substrate. To verify its performance, the prototype was fabricated and measured. The measured results show that the bandwidth in terms of VSWR less than 2 is 21.3% and with a maximum gain of 6.88 dBi. Moreover, the antenna has a stable radiation pattern in the operating frequency band, which agrees well with the simulation results. At the same time, a compact, low-profile structure is obtained. This broadband CP antenna with a simple structure is very suitable for phase array applications.