Miscellaneous active electrical nonlinear devices – circuits – and – Specific identifiable device – circuit – or system – Unwanted signal suppression
Patent
1995-01-25
1997-03-11
Callahan, Timothy P.
Miscellaneous active electrical nonlinear devices, circuits, and
Specific identifiable device, circuit, or system
Unwanted signal suppression
327560, 327311, 330303, 330109, H03K 500, H03B 100
Patent
active
056105517
ABSTRACT:
A filter circuit includes a differential amplifier having a mutual conductance of g.sub.m1, and a transistor T.sub.1 which attenuates an output current of the differential amplifier by 1/.beta. (.beta. is a current amplification factor) is arranged at a stage succeeding to the differential amplifier, whereby terms of g.sub.m1 in equations respectively representative of a resonance frequency .omega..sub.0 and a quality factor Q are multiplied by 1/.beta., respectively. Since the term of g.sub.m1 exists in a numerator within a root symbol (.sqroot. ) in the equation representative of the resonance frequency .omega..sub.0, by arranging the transistor T.sub.1, the resonance frequency .omega..sub.0 can be decreased by 1/.sqroot. .beta. times. Furthermore, since the term of g.sub.m1 exists in a denominator within a root symbol (.sqroot. ) in the equation representative of the quality factor Q, by arranging the transistor T.sub.1, the quality factor can be increased by .sqroot. .beta. times.
REFERENCES:
patent: 5001441 (1991-03-01), Gen-Kuong
patent: 5317217 (1994-05-01), Rieger et al.
"High-Q Active Filter", IBM Technical Disclosure Bulletin, vol. 13 No. 12 May 1971, pp. 3586-3589.
Soliman, Novel Grounded C Biquad Circuits Using the DVCCS/DVCVS, 2213 Frequenz vol. 34, (1980), Okt. No. 10, Berlin, Germany, pp. 288-291.
Patent Abstracts of Japan, vol. 13, No. 243 (E-768), Jun. 7, 1989 of JP 1044615 (Toshiba Corp.), Feb. 17, 1989.
Callahan Timothy P.
Le Dinh T.
Sanyo Electric Co,. Ltd.
LandOfFree
Filter circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Filter circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Filter circuit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-446383