A CMOS High-Q LC Eight-Path Bandpass Filter for Wireless Broadband Applications

This paper would like to prove the feasibility of a new high-Q eight-path bandpass filter. The proposed filter is tuned by using a command circuit made up by a ring voltage controlled oscillator (VCO) with 'XOR' gates. Fabricated in a standard 0.35 mum CMOS, this circuit is intended to replace the SAW filters in wireless broadband applications. Experimental results demonstrate interesting performances; a tunable center frequency range of 200 MHz [300-500 MHz] and a quality factor that can be as high as 200 within the tunable frequency range.