Wideband bandpass filter with multiple reconfigurable bandwidth states

This paper aims to develop a novel building block for designing tuneable wideband bandpass filters. The proposed circuit block mainly consists of short circuit coupled lines and short circuit stubs with pin diodes as tuning elements. This work aims to demonstrate a filter with four reconfigurable bandwidth states developed by combining two tuneable filter circuits designed previously. The filter has a fractional bandwidth tuning range between 13% - 33% centred at 2 GHz. The tested filter shows good agreement with EM simulations and improved insertion loss characteristics, compared to the previously designed filter.