Co-axial fed triple-band and dual-band zeroth order antennas using pseudo-open termination unit cells for C-band applications

Abstract

In this paper, a triple-band and dual-band zeroth order resonance (ZOR) epsilon negative antennas are proposed using two pseudo-open termination unit cells for the case where the shunt ZOR (fsh) is higher than the series ZOR (fse1). The epsilon negative transmission line (ENG TL) resonates fsh while the series ZORs (fse1 and fse2) are excited by the series capacitance of the two pseudo-open termination unit cells. If the series capacitances of the two pseudo-open termination unit cells are different then fse1 and fse2 are excited, else only fse1 is excited. fse1 and fse2 along with fsh results in triple-band ZOR antenna, while a single fse1 with fsh results in dual-band ZOR antenna. The pseudo-open termination unit cells can be placed anywhere around the ENG TL to get proper matching. All the resonances for both the antennas follow zeroth order characteristics which are verified using electric field vector. The measured peak gains of the triple-band ZOR antenna for fse2,fse1 and fsh are 1.14 dBi, 1.39 dBi, and 2.19 dBi, respectively, with dipole mode for fsh. For dual-band ZOR antenna, the measured peak gains for fse1 is 1.4 dBi, and fsh is 2.05 dBi, with dipole mode for fse1 and fsh.