A 1 to 5GHz adjustable active polyphase filter for LO quadrature generation

This paper focuses on the design of a highly tunable active polyphase filter with IRR better than 40dB. The active polyphase filter is implemented as a part of a simple RF receiver to demonstrate its feasibility for wide variety of wireless systems. The design consists of a high frequency adjustable gm-element that is optimized for active PPF. The filter achieves a tuning range of 1 to 5GHz while consuming supply current of 0.7 to 4.4mA. The silicon area of the filter is 64×85μm.