A CMOS Wideband RF Front-End With Mismatch Calibrated Harmonic Rejection Mixer for Terrestrial Digital TV Tuner Applications

Abstract

A wideband direct-conversion RF front-end for Advanced Television Systems Committee terrestrial digital TV (DTV) tuner applications is realized in a 0.18-mu m CMOS technology. In order to effectively solve the critical local oscillator (LO) harmonic mixing problem in an ultra-wideband frequency environment of 48-860 MHz, the combination of a mismatch calibrated harmonic rejection mixer (HRM) and a simple preceding integrated third-order passive RF tracking filter with an external inductor is utilized to obtain 60-80 dB of harmonic rejection for all odd-order harmonic mixing within the DTV spectrum. In addition, an efficient novel calibration algorithm for the HRM is proposed in order to simplify the compensation process. The RF front-end also includes a broadband noise-canceling low-noise amplifier, an attenuator to cover the wide dynamic range, an LO multiphase generator, and peripheral circuits such as an I(2)C serial interface for digital control. The implemented CMOS RF front-end achieves a total gain of 40 dB, output third-order intercept point of 30 dBm, and noise figure of 5.5 dB while consuming a low power of 140 mW from a 1.8-V supply voltage.