Comparative study and analysis of high permittivity and low permittivity continuous phase correcting structures for EBG resonator antennas

This paper presents low-profile continuous phase correcting structures (PCS) for conventional electromagnetic bandgap resonator antennas (ERAs). This PCS has been implemented using a relative high-permittivity-dielectric material and is compared with a low-permittivity Rexolite PCS reported previously. The use of high permittivity materials is not advisable for the PCS design as it increases reflections from the input surface of the PCS; a PCS is supposed to be highly transmitting structure. However, it was found that if a high-permittivity-dielectric PCS is placed above ERA with a proper spacing then high reflections can be used to an advantage. Overall peak directivity of an ERA with TMM4 PCS is 1 dB more than that of the Rexolite PCS along with 44% reduced height profile.