A Transconductor and Tunable High-Pass Filter Linearization Technique Using Feedforward Ca

A linearization technique of a transconductor circuit is proposed in this brief. By adopting a two-path feedforward architecture, the G_m3 component of the transconductor vanishes and a highly linear V-to-I conversion is achieved. This technique consists of self-biased inverters only, and it can be applied to transconductors with differential inputs. It also has an advantage in process scaling and precise bias control is not necessary. A tunable G_m-C high-pass filter for the baseband of a frequency- modulated continuous-wave radar system is implemented using these linearized transconductors. The filter is synthesized with a high-order admittance method. The designed filter is fabricated in a 0.13-μm CMOS process. The filter cutoff frequency can be tuned from 0.15 to 0.75 MHz with a current consumption value of 11-36 mA. An in-band input-referred third-order intercept point of +19.4 dBm and a 1-dB compression point of +5.35 dBm are measured, demonstrating a highly linear filter operation.