Electronically Tunable Active-RC All-pass Filter

Abstract

A second-order active all-pass filter is realized with three op. amp. biquad circuit. The tunability of the filter is achieved by the use of periodically-switched conductances within the circuit in which the regulation of the switching parameter allows the independent adjustment of the delay characteristics. It is shown that the maximum delay time and its corresponding frequency are adjustable independently by changing the ratio of the on-duration in a period to the period of switching. The electronically tunable active all-pass filter can be used for data transmission systems because of its sufficient flexibility of adjustment.

Indexing Terms:

• Active Filter
• Delay Equalizer