Parallel resonator with a resistance and a frequency dependent negative resistance realized with a single operational amplifier

Bandpass
RC
active filters can be realized, according to Bruton's transformation method, with resistively coupled parallel resonators which are formed by parallel connecting of a resistance and a frequency-dependent netative resistance. This paper describes a single operational amplifier resonator which has an inherent finite quality factor. Bandpass
RC
active filters can be thus implemented when the passband is relatively narrow, with performance characteristics comparable to that of currently used
LC
filters, up to frequencies of a few kilohertz.