This letter proposes a design method for a ceramic monoblock dual-band cavity filter using a non-resonant star-junction structure. The proposed junction structure facilitates the extraction of the required external quality factor (Qe) for filter specifications by establishing inductive coupling between the probe and the resonator through a metal bridge and hole configuration. This structure offers high design flexibility, as it can be implemented various shape of metal bridge such as tapered line or stepped structure and support both coaxial probe and planar transmission lines transitions. Simulation results shows the ceramic monoblock dual-band filter realized by the proposed junction structure greater than 20 dB of return loss in the passbands of 1,710~1,785 MHz and 1,920~1,980 MHz, as well as better than 75 dB of isolation (|S21|) in the 1,805~1,880 MHz.
Park et al. (Fri,) studied this question.