A precisely gain controlled RF front end for T-DMB tuner ICs

Abstract

Abstract:A precisely gain controlled RF front end is developed for T-DMB tuner IC applications. A precise RF gain control with 50 dB dynamic range is achieved in RF VGA by employing a capacitive ladder type attenuator. The proposed method enables us to design and analyze very fine gain step VGA concretely. Implemented in 0.13 µm CMOS, the tuner RF front end consumes 9.7 mA at 1.2 V supply. Measured results are NF < 1.5 dB at the maximum gain and the accurate 1 dB gain step is obtained.