A Hybrid Design of Printed Antenna Fed by Coplanar Waveguide With and Without Back Conductor

A hybrid design of coplanar waveguide (CPW)-fed printed antenna with and without back conductor (BC) is presented. An E-shaped strip protruded from the signal strip of the feedline is used to connect the two side (ground) planes of the antenna, and a pair of thin slits cut in the side planes adjacent to the two side arms of the E-shaped strip is employed to tune the input impedance of the antenna with BC. When BC is placed, the antenna is a conductor-backed CPW (CBCPW)-fed side-plane patch antenna, while when BC is removed, the antenna becomes a CPW-fed slot dipole antenna. The antenna is designed to have the side-plane patch and the slot dipole operate at the same frequency, so that it can adapt itself to the presence or absence of a BC. Resonant behaviors and radiation characteristics of the proposed hybrid antenna with and without a BC are presented. Design details and simulation and measurement results are also presented and discussed.