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

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 ( f sh ) is higher than the series ZOR ( f s e 1 ). The epsilon negative transmission line (ENG TL) resonates f sh while the series ZORs ( f s e 1 and f s e 2 ) 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 f s e 1 and f s e 2 are excited, else only f s e 1 is excited. f s e 1 and f s e 2 along with f sh results in triple-band ZOR antenna, while a single f s e 1 with f sh 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 f s e 2 , f s e 1 and f sh are 1.14 dBi, 1.39 dBi, and 2.19 dBi, respectively, with dipole mode for f sh . For dual-band ZOR antenna, the measured peak gains for f s e 1 is 1.4 dBi, and f sh is 2.05 dBi, with dipole mode for f s e 1 and f sh .