Compact UWB bandpass filter based on simple radial stub resonator structure


In this letter, a new compact microstrip ultra‐wideband (UWB) bandpass filter (BPF) is proposed. Using a new electrical model leading to a simple structure based on radial stub resonator (RSR), its originality resides in its noteworthy simple design approach where the filter response can be accurately adjusted by tuning three parameters only. The fabricated filter shows a good agreement between simulations and measurements whereas fulfilling UWB requirements, i.e., enhanced selectivity, good matching and flatness within the entire band of operation, and sufficiently constant group delay. With an overall size of 9.53 mm x 8.28 mm, a high compactness has been achieved, making this structure one of the most compact filters ever reported.