Triple-frequency annular-ring slot antennas fed by CPW and microstrip line

Abstract

In this paper, we present a simple design of a triple-frequency annular-ring slot antenna fed by coplanar waveguide or microstrip line. The proposed antenna consists of three concentric annular-ring slots and the three operating frequencies are obtained by means of the multiple radiating annular-ring slots, each supporting strong electric field and radiation at resonance. The three operating frequencies of the proposed antenna are mainly decided by the circumferences of the three annular-ring slots, respectively.