A biquad wideband signal processing circuit can operate over bandwidths of 50 MHz to 20 GHz or more. The biquad circuit employs a configuration of integrators (transconductors), buffers, and scalable summers that can be implemented using deep sub-micron CMOS technology. Combining this scaling with high gain/high bandwidth enables implementation of feedback and programmability for broadband analog signal processing. A biquad circuit implementing a number of parallel integrator lines having adjustable gain provides greater accuracy, stability, and bandwidth, and allows for control of process variations and temperature variation in real-time.