BiCMOS OTA for high Q very high frequency continuous-time bandpass filters

In this paper, we show that BiCMOS technology is really suited to the implementation of high-Q, VHF, Gm-C continuous-time bandpass filters. The major problem of such filters is the output resistance value of the transconductors which must be very high. The design approach is based on the use of a negative resistance element in BiCMOS technology which allows the output resistance value to be increased close to 50 M/spl Omega/ without any limitation in the bandwidth of the transconductor circuit. Simulation results of a biquadratic bandpass filter with center frequency f/sub 0/=84.6 MHz and quality factor Q/sub 0/=30 conclude the paper.