Reconfigurable Bandpass Filter With Wide-Range Bandwidth and Frequency Control

In this brief, a novel reconfigurable bandpass filter with adjustable center frequency and wide bandwidth reconfiguration is presented. The proposed bandpass filter is formed by cascading tunable high-pass (HP) and low-pass (LP) filter sections directly. Both the operating frequency and bandwidth of the reconfigurable bandpass filter can be reconfigured independently by tuning the frequencies of the band edges, which are controlled by the cut-off frequency of the HP and LP filter sections. Finally, the proposed filter is designed, fabricated and measured for validation purposes. The measured results demonstrate that the bandwidth can be tuned from 180 MHz to 1390 MHz at the fixed center frequency with tuning ratio up to 7.8:1. Center-frequency agility is also verified with different constant absolute bandwidth of 400 MHz, 600 MHz, and 800 MHz The measured results show that proposed filter possesses the advantages of simple implementation, wide bandwidth tuning range, wide frequency tuning range, and compact size.