Broadband circular patch antenna with monopolar radiation pattern for indoor wireless communication

A circular patch antenna with wide impedance bandwidth and monopolar radiation pattern for indoor wireless communication is proposed and analyzed in this paper. The antenna is a combination of circular patch and four capacitive feeds. By incorporating a cross-connected shorted conducting strip over the circular patch, the proposed antenna provides an enhanced impedance width of 65.4%, ranging from 1.46 to 2.88 GHz. Four capacitive feeds improve the design flexibility and make the ripple of horizontal radiation pattern less than 3 dB. A prototype of the proposed structure has been fabricated and measured. Both the simulated and measured results show that the proposed design has a stable monopolar radiation pattern over a wideband frequency range and a peak gain of 5.0 dBi, which can be widely applied for indoor wireless communication such as GSM1800, CDMA2000, WCDMA, and TD-LTE systems.