A Dual-Frequency Broadband Design of Coupled-Fed Stacked Microstrip Monopolar Patch Antenna for WLAN Applications.

A novel dual-frequency broadband design of a stacked microstrip monopolar patch antenna is proposed for WLAN applications. The antenna is composed of a via-loaded ring on the bottom layer and a circular patch on the top layer, both of which are coupled-fed by a circular coupler. A broad lower band is generated by converging the TM01 and TM02 modes of the via-loaded ring, and a broad upper band is yielded by coupling the TM03 mode of the via-loaded ring and the TM02 mode of the circular patch. Measured results show that the proposed antenna provides a broad lower band from 2.28 to 2.55 GHz and a broad upper band from 5.15 to 5.9 GHz with a low profile of 6 mm. Monopole-like radiation patterns are obtained in the dual bands with peak gains in the lower and upper bands of about 5 and 6 dBi, respectively. [ABSTRACT FROM PUBLISHER]