High Permittivity Tape Transmission Line Embedded in Low Dielectric Support at Millimeter-Wave Frequencies

A new guiding structure which consists of a high permittivity tape inserted in a below cutoff parallel metal plate waveguide was proposed for mass productive and low loss dielectric circuits. In this paper, a supporting technique of the high permittivity tape was considered. First, a relative bandwidth versus an aspect ratio of the high permittivity tape was calculated. According to these results, it was obvious that the relative bandwidth was width than that of conventional rectangular metal waveguides when the high permittivity tape was inserted in the vertical mid-plane of the parallel metal plate waveguide. Next, a transmission line which consists of the high permittivity tapes embedded in a low dielectric support was proposed and the transmission characteristics were analyzed. As the result, a wide-band characteristic was obtained because a single mode transmission bandwidth of the lowest order mode was 45 GHz at a center frequency of 50 GHz. In addition, this guide exhibited a flat-dispersion curve in a bandwidth from 40 GHz to 75 GHz and the transmission loss was 15 dB/m in this frequency range.