A CMOS resistive feedback single to differential low noise amplifier with multiple-tuner-outputs for a digital TV tuner

Abstract

A CMOS resistive feedback single to differential low noise amplifier (S-to-D LNA) with single-ended multiple tuner outputs (MTOs) is implemented for a digital TV (DTV) tuner using a 0.18-µm CMOS process. In order to achieve wideband output balancing with high gain, low noise figure (NF) and high linearity, the S-to-D LNA exploiting the resistive feedback with enhanced loop gain is proposed. The proposed S-to-D LNA also has single-ended MTOs which are made by combining the differential output of the S-to-D LNA without second-order distortion for supporting multiple tuner and multiple stream applications. This leads the excellent IIP2 at both differential output and single-ended MTOs of the proposed S-to-D LNA. A voltage gain of 19.5 dB, an average NF of 2.4 dB, an IIP3 of −2 dBm and an IIP2 of 26 dBm are obtained at differential output. At single-ended MTOs, a voltage gain of 12.5 dB, an average NF of 2.9 dB, an IIP3 of −1.5 dBm and an IIP2 of 25 dBm are obtained.