Wideband Zeroth-Order Resonance Antenna Combined with TM010 Mode Having Folded Mushroom Structure

Abstract

In this paper, a wideband folded mushroom antenna which operates from a zeroth-order resonance (ZOR) mode to a TM010 (lambda(0/2)) mode is presented. By folding a mushroom structure, the TM010 mode is down-shifted toward the frequency of the ZOR mode and, thus, the wideband is achieved without any additional structure. The optimized antenna has a dimension of 0.365 lambda(0) x 0.247 lambda 0 x 0.182 lambda(0) at the center frequency. As a result, a 10dB fractional bandwidth is measured to be 68.3% which ranges from 2.38 GHz to 4.85 GHz. Moreover, the measured radiation efficiency is above 80% in the whole band. The measured result shows a good agreement with the simulated result.