A CPW-FED SLOT ANTENNA WITH EMBEDDED RING-TYPE STRIP FOR DUAL-FREQUENCY OPERATION

摘要

The coplanar waveguide-fed planar slot antenna with the embedded ring-type strip for dual-frequency operation is investigated and experimentally explores in this letter. The prototype, which is implemented on the 0.8-mm FR-4 substrate withε_r = 4.4, indicates that the embedded ring-type strip offers extended path for the electric current flow, achieving 45.1% size reduction of the fundamental resonant mode. The ratio of the center frequencies of the first two resonant bands can be tuned within a range wider than 1.81 by increasing the radius and line width of ring-type strip. Furthermore, the fundamental resonant mode can be shifted to the higher frequency to combine with the second resonant mode of the circular slot, indicating the wideband operation with the bandwidth of 1332 MHz (40.5%).