High-selective microwave active bandpass filter using transmission line interference sections

A new microwave active bandpass filter codguration is presented in this Paper. Interference sections based on pairs of transmission Lines connected in parallel are used in the proposed structure to synthesize high-order filter responses. the desired filter passband. Finally, the theoretical results are validated with the design, constrnction in microstrip technology, and characterization of a wideband active filter prototype at 2.5 GHz