A very compact monopole antenna with variable frequency band-notch for ultra-wideband applications

A novel printed band-notched monopole antenna for ultrawideband (UWB) applications with variable frequency band-notch characteristics is presented. This antenna consists of a rectangular radiating patch with an inverted U-shaped slot, which a pair of L-shaped conductor strips protruded on it, and an arrow-shaped ground plane. In this state, the proposed antenna without band-notch can operate over the frequency band between 2.96 and 20.8 GHz for VSWR ≤ 2. By cutting a pair of rectangular slots on the bottom of inverted U-shaped slot on the radiating patch, frequency band-stop performance is generated, while showing the band rejection performance in the frequency band of 5 to 6 GHz, and results show that the proposed antenna has a wide bandwidth from 2.54 to 25.7 GHz. The designed antenna has a simple structure and compact size of 10 × 15.5 mm².