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

Abstract

The dual-frequency properties of a dual annular-ring slot antenna fed by coplanar waveguide (CPW) and microstrip feedline are presented and experimentally studied. The proposed antenna is constructed by dual concentric annular-ring slots fabricated on FR4 substrate with single feed. The proposed slot antennas have good impedance matching for the two operating frequencies with a frequency ratio ranging about 1.34/spl sim/3.11 and 1.4/spl sim/1.74 can be achieved for CPW-fed and microstrip-fed.