A circular CPW-fed slot antenna resonated by the circular loop for broadband circularly polarized radiation

Abstract

The coplanar waveguide (CPW) fed circular slot antenna, resonated by the circular loop with a narrow opening, is designed for obtaining broadband circularly polarized (CP) radiation. The length of protruded signal strip (L-S) is utilized to adjust the phase difference between two orthogonal field components in the circularly polarized waves. In this design, the proposed antenna has the minimum return loss of -56.5 dB at the frequency of 2.403 GHz. The impedance and 3 dB axial-ratio bandwidths can reach up to 740 MHz or 33.3% and 390 MHz or 16.6%, respectively. In addition, the simulated results are about as good as those of the measured ones. (C) 2008 Wiley Periodicals, Inc.