A High Linearity VHF Programmable Gain LNA

A VHF (30MHz-300MHz) band digitally programmable low noise amplifier (LNA) has been implemented with a 0.25um standard CMOS process for VHF CMMB mobile TV tuners. Utilizing a T-match input network, input matching of more than a decade bandwidth is achieved across all gain settings. Adopting the multiple gated technique, gain flatness enhancement and capacitor reuse etc., the proposed LNA demonstrates 3 gain settings of 20dB, 6dB, -9dB with S11 below -12dB at every gain setting. At a power supply voltage of 2.5V, the LNA consumes less than 10mA current, -6dBm IIP3 and a Noise Figure (NF) of less than 2.9dB at 20dB gain setting over the VHF band.