Abstract: An RF front-end circuit for a fully integrated CMOS DTV tuner is presented in this paper,where double-conversion low IF architecture is employed.The chip is implemented in a 0.18μm CMOS process,which includes a wideband low noise amplifier,and upconversion and downconversion mixers.The measurement results show the front-end has good input matching and a 20dB variable gain range.In the maximum gain mode,the gain is +33dB,the single sideband noise figure (SSB NF) is 9.6dB,and the input referred third-order intercept point (IIP3) is -6dBm;In the minimum gain mode,the gain is +14dB,the SSB NF is 28dB,and the IIP3 is +8dBm.The RF front-end drains 30mA current from a 1.8V supply and the die area is about 1.04mm×0.98mm.

Key words: TV tuner, double conversion, low IF, fully integrated