BROADBAND CIRCULARLY POLARIZED BEAM-STEERING ANTENNA ARRAY FOR WIRELESS APPLICATIONS

摘要

This article describes the implementation of a broadband circularly polarized (CP) antenna array for switched beam applications. The antenna comprises of four identical CP slot elements in a 2 x 2 configuration that uses a 4 x 4 feeding network. Each CP slot element in the array is sequentially rotated with respect to each other to enhance the antenna's axial-ratio (AR) bandwidth. Measured results confirm the array exhibits an impedance bandwidth of 2.25 GHz that extends over the frequency range 4.6-6.85 GHz (similar to 40%) for S-11 <= -10 dB, and 3 dB AR bandwidth of 1.7 GHz that extends between 4.8-6.5 GHz (similar to 30%). The antenna's gain is in excess of 6.8 dBi between 5-6 GHz. (C) 2014 Wiley Periodicals, Inc.