Gm-C based band pass filter

Design of Transconductance-C (Gm-C) filters, which can operate from a few kHz to 100 MHz, have been presented. Two operational transconductor amplifiers (OTA) are used in a mirrored cascade structure. This structure offers a flexible common mode range. The band pass filter uses two OTAs and two capacitors. The structure offers a variable center frequency and variable Q. These center frequency and the Q values can be changed by keeping one capacitor fixed and by varying the second one. The value of the two capacitors is varied to obtain different bandwidths and center frequencies. The theoretical and the simulation result match closely.