A bandpass filter using electrically coupled TM/sub 01 delta / dielectric rod resonators

A compact bandpass filter having Chebyshev, low-loss, and good spurious response has been constructed by placing high-Q TM/sub 01 delta / dielectric rod resonators coaxially in a TM/sub 01/ cutoff circular waveguide. Precise design of the high-Q resonators and interresonator coupling is performed by the mode-matching technique. The interresonant coupling is equivalently expressed by a capacitively coupled LC resonant circuit. A four-stage Chebyshev filter having ripple of 0.035 dB and equiripple bandwidth of 27 MHz at the center frequency of 11.958 GHz, fabricated using these resonators, is discussed.<>