A Tunable Bandstop Filter Based on Source Follower

Abstract

A tunable bandstop filter based on source follower is presented. The filter is designed using a source follower architecture with partial positive feedback and feed-forward paths using 0.18µm CMOS technology. The filter consumes about 1.4 mW from a 1.8V power supply, and it is designed to have 1.5GHz center frequency with 360 MHz bandwidth and 80 dB attenuation. The filter achieves 10 dBm IIP3 for two tones at 1.495GHz and 1.505 GHz.