Effect of ferrite substrates on antenna miniaturization

Abstract

This study has been carried out to estimate the effect of electro-magnetic properties of soft magnetic ferrites on the performance and miniaturization of antennas operating in the ultra high frequency (UHF) range. Compared with dielectric materials, ferrites used as substrates effectively reduce the resonance frequency of tapered slot antennas without noticeable reduction of bandwidth and gain. For example, a NiZn ferrite antenna with a size of 40 mm imes 10 mm imes 2.4 mm showed an antenna gain of --7.9 to --3.04 dBi in the frequency range of 450 -- 700 MHz. Hence, these data suggest that magnetic antennas are applicable to terrestrial, digital, multimedia broadcasting (T-DMB) and digital, video broadcasting, handheld (DVB-H) phones.