Design of ultra-wideband antenna with dual band-notched function

The paper presents a compact ultra-wideband coplanar-waveguide-fed monopole antenna with dual band-notched function. Two types of simple slots, L-shaped and semicircular, are cut in the radiating patch to realize the dual band-notched function in the frequency ranges of3.3 to 3.7 GHz for world interoperability for microwave access(WiMAX) applications and 5.150 to 5.825 GHz for wireless local area network(WLAN) applications. Experimental results show that the voltage standing wave ratio (VSWR) in the working band of 3 to 14 GHz is less than 2 except in the two band notches (VSWR more than 4). The proposed antenna has an almost omnidirectional radiation pattern and a good stable gain over the whole working band except the two band notches. The antenna has a small size and can be easily processed, which can greatly simplify the circuit design of a communication system.