Although TE0n delta mode ceramic resonators are usually used at centimeter
frequencies, they have difficulty in making wide-band band-pass filters in
the millimeter-wave region due to the weak coupling factors between TE0n de
lta mode resonators and input/output waveguides. In order to overcome such
difficulty, a band-widening technique of the ceramic resonator loaded band-
pass filter has been proposed. The EHnm delta modes were regarded as spurio
us modes so far, but it is clear that the coupling factors are larger than
those of the TE0n delta modes from the results of experimental consideratio
ns in this paper. By using the EH11 delta mode ceramic resonators, 5-pole,
1 dB Chebyshev ripple NRD guide band-pass filter has been fabricated for th
e applications to broad-band millimeter-wave communication systems at 60 GH
z. The filter has great advantages such as the wide passband beyond 2 GHz a
nd low excess insertion loss of less than 0.3 dB.