A Compact Wideband Circularly Polarized Planar Filtenna Using Synthesis Technique for 5 GHz WLAN Application

Abstract

This paper presents a compact wideband circularly polarized planar filtenna based on filter synthesis methodology. The proposed filtenna consists of third order hairpin line resonator filter coupled with an circularly polarized hexagonal shaped radiating element. The better integration between antenna and filter helps in achieving both compactness and high frequency selectivity. The proposed filtenna exhibits a wideband filtering response with an impedance bandwidth of 35.77% (3.92–5.63 GHz), a wide axial ratio bandwidth of 34.94% (3.66–5.21 GHz), and a peak gain of 2.25dBic within its operating bandwidth. In order to validate its practicability, the filtenna is designed and fabricated. The measurement results shows that the proposed filtenna exhibits good stopband gain rejection, good selectivity at band edges, flat passband gain, and a wide axial ratio bandwidth well suited for 5 GHz WLAN application.