A circular loop antenna with a parasitic circular loop for triple-band operation

A circular loop with a parasitic circular loop for triple-band operation is investigated numerically by using the method of moments. There are a feed element and a parasitic element on the ground plane. Each loop has a gap and the position of the gap is adjusted to get triple frequency bands. The VSWR bandwidths (/spl les/2) of 5%, 13% and 4% are obtained for a 1.55 GHz, 1.9 GHz and 2.44 GHz band.