| 摘要 |
<p>A new type of frequency-tunable active notch filter (Fig. 3) achieves frequency selectivity through interaction among input derived signal components that are passed through parallel signal channels (301, 302, 303) in a forward-only direction. The notch filter differs from earlier channelized notch filters by using multiple, instead of just one, bandpass channels that maintain required forward signal flow in the main, passband-determining signal path without signal distortion at passband frequencies. The new approach has been experimentally verified with a hybrid-integrated three-channel filter whose 40dB-deep band-reject notch can be continuously tuned, with the help of voltage-controlled variable-capacitance elements, from 9.5 GHz to 10.5 GHz.</p> |
