Design of a Planar Segmented Circular Loop Antenna for Omnidirectional Radiation at 5.8 GHz

A planar segmented circular loop antenna is designed for operation at 5.8 GHz with omnidirectional radiation pattern. This novel printed antenna, fabricated on a low-loss substrate, is composed of alternating top- and bottom-layer conducting segments of annular geometry, with the regions of conductor overlap functioning as planar capacitors to minimize phase variation in the electrical current. Measurements reveal an omnidirectional pattern with gain of 1.58 dBi, efficiency of 81%, bandwidth of 6%, and input impedance close to 50 Ω. The antenna is proposed as a transceiver for applications that use the 5.8-GHz ISM band.