MMIC active bandpass filter using negative resistance elements

This paper describes a monolithic bandpass filter using lumped L-C resonators with single transistor negative resistance elements. The measured response of the filter exhibits a 400 MHz 3 dB-bandwidth centered on 4.7 GHz, and has 0 dB insertion loss with only /spl plusmn/0.1 dB ripple in the pass-band.<
>