Miniaturized Band Pass Filters Using Half Wave Dielectric Resonators with Improved Spurious Response

The capacitive coupled transmission line band pass filters were miniaturized about from 1/4 to 1/6 of size of the conventional filters without increasing insertion loss by using ceramics which has high dielectric constant and excellent temperature stability (within /spl plusmn/2 PPM//spl deg/C). The spurious response of the second and the third harmonics were clearly shifted from multiples of the dominant mode by using "composite TEM cavity resonator." The new band pass filters are applied to L or S band of frequency.