A Compact Monopole Antenna With Filtering Response for WLAN Applications

A novel compact monopole antenna with filtering response for WLAN applications is presented in this paper. The antenna is composed of a capacity-loaded matching patch, two resonators, and two end-coupled monopoles. The resonators consist of wide rectangular patches and narrow shorted lines to form the resonance, and the resonators are printed on the different layers to increase the design flexibility. Two meandering monopoles are located at the edges of the top layer with capacitive coupling at each other's end. The mutual couplings between the meander monopoles are utilized to produce two radiation nulls at the two band-edges. Based on the design method, the prototype of the proposed antenna was designed, fabricated and measured. The measured results show that the antenna has a broad bandwidth of 16% for S 11 <; -10 dB. Also, ideal omnidirectional radiation patterns, and steep band-edge selectivity with two radiation nulls are achieved for the proposed antenna.