Compact Multi-Layer Circularly Polarized Hexagonal-Spiral Antenna for Wireless Applications

Abstract

Circularly Polarized (CP), Compact Hexagonal-Spiral (HS) antenna is proposed for wireless communication applications. The proposed antenna is three layered coax-fed antenna, having an air gap between ground layer and hexagonal-spiral patch antenna layer. A rectangular stub is used to enhance the performance of the antenna in terms of S11 and CP radiation. The overall size of the proposed antenna is $0.483\boldsymbol{\lambda}\mathbf{o}\times 0.483 \boldsymbol{\lambda}\mathbf{o}\times 0.1\boldsymbol{\lambda}\mathbf{o}$. The 10dB Return Loss (RL) bandwidth of the antenna is 1.5 GHz (5.5 GHz to 7 GHz) and 3dB Axial Ratio (AR) bandwidth is 500 MHz (5.55 GHz to 6.05 GHz) with a gain of 4.2 dBi. The minimum AR value obtained is 0.12dB at the CP resonance of 5.8 GHz and it is suitable for IEEE 802.16d Wi-MAX and C-band Satellite applications. The proposed antenna is fabricated and tested with Network Analyzer for S11.