Abstract
A miniaturized dual-mode bandpass filter with controllable harmonic response for dual-band applications is presented in this paper. The new bandpass filter is designed with loading distributed capacitors in the inner area of conventional dual-mode loop resonator. This loading can realize both compact size and controllable harmonic response of the filter. A demonstrated filter with the dual-band operating at 1.8 and 2.6 GHz was designed, fabricated and measured. Simulated and measured results indicate that a high selective dual-mode dual-band filter with its size reduced to 34.5% of the conventional case at about 1.8 GHz has been achieved.