A 184 mW fully integrated DVB-H tuner with a linearized variable gain LNA and quadrature mixers using cross-coupled transconductor

A fully integrated direct conversion DVB-H tuner is realized in a 0.5-mu m SiGe BiCMOS technology. To meet the stringent linearity requirement while keeping low power consumption, novel linearization techniques for a variable-gain low-noise amplifier (VG-LNA) and a mixer are proposed. The proposed linearized VG-LNA has a variable gain range of over 50 dB, noise figure of less than 2.6 dB over the frequency range from 200 to 1000 MHz, and IIP3 of more than -10 dBm at a current consumption of 2.1 mA. The quadrature mixer with the proposed linearization technique achieves OIP3 of more than 25 dBm at a current consumption of 5 mA. In addition, a new offset-cancel feedback is introduced for the baseband block of a direct conversion receiver, which keeps the high-pass cutoff frequency independent of the baseband VGA gain. The fabricated tuner IC satisfies all the DVB-H requirements at a power consumption of 184 mW.