The Design of a Biquadratic Filter [The Analog Mind]

Biquadratic filters (“biquads”) are commonly used in radio frequency (RF) receivers to remove unwanted signals (“blockers”) and noise. We have studied the basic properties of such filters in [1] and pointed to the Tow-Thomas (TT) biquad as an efficient implementation. In this article, we design a continuous-time low-pass filter (LPF) based on this topology for Wi-Fi receivers.