Design of Band Pass Filter using active inductor for RF receiver front-end

Abstract

The Band Pass Filters are commonly used in wireless receivers and transmitter. The usage of spiral inductor in the band pass filters requires large chip area which can increase the band pass filter size and is difficult to obtain high Q-factor. This paper presents the active inductor based band pass filter using TSMC 0.18µm RF CMOS process. The band pass filter is realized using active inductor with suitable input and output buffer stages. The active inductor circuit uses the PMOS cascode structure as the negative transconductor of a gyrator. This structure provides the negative resistance to reduce the inductor loss with wide inductive bandwidth and high resonance frequency. The tuning of the center frequency is achieved through the controllable current sources. This active inductor demonstrates a maximum quality factor of 244 with a 154nH inductance. The simulation result of band pass filter designed at 100MHz has the gain of 6.129 dB and input return loss of −11.474 dB. The simulated IIP3 is −19 dBm and power consumed by the BPF is 28mW.