Title :
Simple electronically tunable 2nd-order active filter
Author_Institution :
University of Reading, J.J. Thomson Physical Laboratory, Reading, UK
Abstract :
A new current-tunable 2nd-order active filter is described which is based on the variation of the transconductance of a bipolar transistor with bias current. The circuit can give a lowpass or bandpass 2nd-order response or can be cascaded to give a high-order all-pole tunable filter. Measurements have indicated that a tuning range of at least four decades is possible with a dynamic range of 75 dB.
Keywords :
active filters; band-pass filters; bipolar transistor circuits; low-pass filters; tuning; bandpass filter; bipolar transistor; electronically tunable active filter; lowpass filter; second order active filter; transconductance;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19770187
