Digitally programmable active RC bandpass filter with constant a

Details Digitally programmable active RC bandpass filter with constant a Digitally programmable active RC bandpass filter with constant a

1978-08-25

1980-11-04

Mullins, James B.

Amplifiers

Signal feedback

Amplifier in signal feedback path

330107, H03F 134

Patent

active

042322693

ABSTRACT:
A narrow-band RC active bandpass filter, in which the center frequency may be changed by changing the resistance values of certain resistive elements, has the certain resistive elements switchably connectable into and out of the RC network so that the ratio of time during which the resistors are connected to the network to the time during which resistors are not connected to the network determines the effective resistance thereof. A programmable timing circuit has a plurality of outputs with each output supplying a different number of equal width pulses during a predetermined like time period whereby each output corresponds to a different ratio. The timing circuit actuates and deactuates the switchable connection from a selected output thus deriving the required effective resistance for a predetermined center frequency. The bandwidth of the passband is set by a different resistive element and remains substantially unchanged as the center frequency is changed by changing the effective resistance of the certain resistive elements.

REFERENCES:
patent: 3747007 (1973-07-01), Geitner
patent: 4009400 (1977-02-01), Harris et al.
Jenkins, "Active Filter has Separate Band and Frequency Controls", Electronics, Sep. 11, 1972, p. 110.
Kaehler, "Periodic-Switched Filter Networks-A Means of Amplifying and Varying Transfer Functions", IEEE Journal of Solid-State Circuits, Aug. 1969, pp. 225-230.
Bruton et al., "Tunable RC-Active Filters Using Periodically Switched Conductances", IEEE Transactions on Circuit Theory, vol. CT-20, No. 3, May 1973, pp. 294-301.

Affiliated with

Also associated with

Rating

Digitally programmable active RC bandpass filter with constant a does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Digitally programmable active RC bandpass filter with constant a, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Digitally programmable active RC bandpass filter with constant a will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1647525