Novel microwave bandpass filter with compact size and good out-of-band performance for microwave photonic filter applications

In this paper a novel microwave bandpass filter (BPF) with extended out-of-band rejection is presented. The BPF structure is based on a novel reduced size microstrip resonator which consists of two parallel lines in combination with a short-circuited stub. A BPF operating at 1.85 GHz with 11.11% fractional bandwidth (FBW) is designed, simulated and fabricated. Excellent agreements between simulated and experimental results were obtained. The electrical characteristics of the fabricated BPF allow its use in a microwave photonic filter (MPF) demonstrating in this way a practical application.