Design and Analysis of a Small-Size, Flag-Shape UWB Antenna with Dual Notch Band Using Mushroom Structure

Abstract

A small-size, flag-shaped microstrip-fed printed UWB antenna with dual notch band (NB) is investigated. The essence of flag configuration is evolved from the regular hexagon where both shapes provide UWB responses. Then, the WiMAX and WLAN notch bands are created by using electromagnetic bandgap (EBG) structures for avoiding potential interference. A microstrip line-based model is employed to investigate the NB characteristics of EBG. Various parameters, surface current distribution and input impedance are analyzed to understand the effects of the mushroom. The measured operating frequency of the proposed antenna is from 2.91[Formula: see text]GHz to 10.88[Formula: see text]GHz along with excellent rejection bands of 3.2–3.54[Formula: see text]GHz and 5.13–5.6[Formula: see text]GHz, respectively, for [Formula: see text][Formula: see text]dB. The experimental result has good correlation with the simulated one. The designed antenna exhibits minimal gain variation, appreciable efficiency, stable radiation patterns, transfer function and the time-domain study results correspond well to [Formula: see text] in the pass band. Therefore, satisfactory results ensure its ability to work as a UWB antenna.