1. Filter fundamentals2. The approximation problem3. Active elements4. Realization of first- and second-order functions using opamps5. Realization of high-order functions6. Simulation of LC ladder filters using opamps7. Wave active filters8. Single operational transconductance amplifier (OTA) filters9. Two integrator loop OTA-C filters10. OTA-C filters based on ladder simulation11. Multiple integrator loop feedback OTA-C filters12. Current-mode filters and other architecturesAppendix A. A sample of filter functions