Miniaturized ENG ZOR antenna with high permeability material

Abstract

The development of the antenna which has small size and broad bandwidth is the most important issue in wireless communication system. To reduce the size of an antenna, the epsilon negative (ENG) zeroth-order (ZOR) mushroom antenna which has unique property of an infinite wavelength wave at specific non-zero frequency was proposed [1]. Up to now, many ENG ZOR patch antennas are designed with a high permittivity (εr >1) substrate, resulting in narrow bandwidth. In this paper, to obtain broad bandwidth of antenna, a meandered via and/or a high permeability (μr >1) substrate are employed in ENZ ZOR antenna. First, if a straight via of mushroom ENG ZOR antenna is replaced by the meandered via, the shunt inductance increases and the size of antenna is reduced. When the size of an ENG ZOR antenna is reduced using a high permittivity substrate, the bandwidth of antenna decreases due to the increased shunt capacitance. However, the miniaturization of the ENG ZOR antenna can be achieved using a meandered via without narrowing bandwidth [2]. Second, to obtain a broad bandwidth, a ferrite substrate (μr>1) is applied to an ENG ZOR antenna since it is well known that the patch antenna having broader bandwidth can be designed with a high permeability substrate [3]. It will be presented that several miniaturized ENZ ZOR antennas having improved bandwidth can be designed using a meandered via and/or a high permeability (μr >1) substrate. © 2010 IEEE.