A Highly Linear CMOS Active Inductor and Its Application in Filters and Power Dividers

A high linearity active inductor with a maximum measured Q of 70 and an input 1 dB compression point (P-in,P-1dB) of +8 dBm (associated with a 10% increase in inductance from its small signal value with higher input power) is presented in 180 nm CMOS. Applications of such an inductor in extending the P-in,P-1dB of a Wilkinson power divider and a fully integrated second order capacitively coupled bandpass filter for blocker tolerant receivers are also demonstrated. Up to an input power of +5 dBm, the power divider is seen to have a measured insertion loss (S-21) of <1.5 dB. In each case, to the best of our knowledge, this work reports the highest measured P-in,P-1dB.