Compact Ultra-Wideband (UWB) Bandpass Filter Using Dual-Stub-Loaded Resonator (DSLR)

A compact ultra-wideband (UWB) bandpass filter using dual-stub-loaded resonators (DSLR) is presented. The DSLR is analyzed by using the odd- and even- mode method. Four resonant modes can be tuned by the DSLR in 3.1 GHz - 10.6 GHz, and a pair of transmission zeros can be generated at the lower and upper stopband when the DSLR is applied to a UWB filter. Therefore a UWB bandpass filter is realized with good skirt selectivity, harmonic suppression, as well as compact size. Finally the proposed filter is simulated and fabricated. The measured results are in good agreement with the predicted one, demonstrating this structure is feasible in practical use.