EXPERIMENTAL DESIGN OF MILLIMETER-WAVE NONRADIATIVE DIELECTRIC WAVEGUIDE FILTERS.

A nonradiative dielectric waveguide has no radiation from the bends or discontinuities, it has low loss, and is suited for millimeter-wave integrated circuits. This paper studies the bandpass and band-rejection filters built by using such waveguides at the 50-GHz frequency band. In general, the filters are designed by the coupling coefficients of resonators and loaded Q-factors, but theoretical evaluation of these values is not easy. An experimental design technique is discussed which can also be applied to the filter structure that is difficult to solve analytically. As an example, we designed and fabricated 3-pole bandpass and bandstop filters having center frequency of 49. 5 GHz built from circular post resonators of Teflon.