New compact pentaplexer using stub-loaded stepped impedance resonators

This paper presents a compact pentaplexer using the stub-loaded stepped impedance. The pentaplexer is composed of five pairs of stepped impedance resonators with short-circuited stub at the center of resonator for each channel (passbands). By properly tuning the impedance ratio (K) and length ratio (α) of the stepped impedance resonators, five channels frequencies can be easily determined. To improve the passband selectivity, the source-load coupling lines are designed to correspond to the quarter-wavelength at the center frequency for each channel. The proposed pentaplexer is showing a simple configuration, an effective design method and a compact circuit size.