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United States Patent | 3,621,407 |
November 16, 1971 |
A multiloop RC active filter network having low parameter sensitivity with low amplifier gain comprising at least two passive components and two voltage amplifiers one of which has a positive gain K.sub.1 which is less than unity and the other providing a negative gain of magnitude of K.sub.2 in the outer feedback loop. These circuits can provide any Q and can be made to oscillate with K.sub.1 and K.sub.2 within certain given ranges. Monolithic integrated circuit thick or thin film techniques are used in the preferred embodiment to provide the passive RC components.
Current U.S. Class: | 327/552 ; 330/109; 330/85; 333/172 |
Current International Class: | H03H 11/12 (20060101); H03H 11/04 (20060101); H03B 5/00 (20060101); H03B 5/20 (20060101); H03b 001/04 () |
Field of Search: | 328/165,167,142,145 307/229,230,295 330/85 333/70R,80 |
3107331 | October 1963 | Barditch et al. |
3333207 | July 1967 | Bento et al. |
3448289 | June 1969 | Harris |