Miniaturized ENG ZOR antenna with high permeability material

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. In this paper, the miniaturized ENG ZOR antenna having improved bandwidth is presented. To obtain broad bandwidth of the miniaturized ENG ZOR antenna, a meandered via and/or a high permeability substrate are employed. As a result, the fractional bandwidths of the proposed mushroom ENG ZOR antenna is obtained as 1.58% (^=0.36), which is 7.9 times as broad as that of a mushroom ENG ZOR antenna (kr=036).