A compact zeroth-order resonant antenna based on modified Jerusalem mushroom structures

In this paper, a compact zeroth-order resonant composite right/left-handed (CRLH) antenna based on modified Jerusalem mushroom structure is proposed. The modified Jerusalem cross-shaped mushroom is engineered to attain a low capacitance but a high inductance, which in turn reduce the resonant frequency and hence to fulfill the goals of antenna miniaturization with efficiency enhancement. In particular, the shunt capacitance and series inductance are tailor-made by controlling the area and width of the mushroom patch. The proposed small antenna occupies a footprint of 0.23λ0 x 0.52λ0 square wavelength at 3.5 GHz. From the results, the proposed antenna exhibits the omnidirectional dipole-like radiation pattern and has a realized gain of 1.15 dBi. Moreover, investigation on three different types of CRLH antenna, namely conventional mushroom, Jerusalem and modified Jerusalem is undertaken and their performances are compared