Circular Polarized Coplanar Waveguide Fed Slot Antenna For ISM Band Application

Abstract

A planar circular polarized slot antenna with multiple stubs using coplanar waveguide feed (CPW) technique is introduced in this letter. A rectangular slot is introduced in the ground plane and a feeding stub is inserted in the rectangular slot with stub ending into a quadrature feed excitation as the primary stub modifies into a configuration which works as quadrature feed. Two rectangular grounded rings are also incorporated in the structure along with a rectangular conducting stub embedded in the ground with both placed on either side of primary stub. This results in generation of circular polarized radiations for a frequency range of 3 GHz to 4.25 GHz for which S11< ‒ 10 dB and Axial ratio < 3dB and the excited resonating band lies in the ISM band.