Abstract: A fully integrated direct-conversion digital satellite tuner for DVB-S/S2 and ABS-S applications is presented. A broadband noise-canceling Balun-LNA and passive quadrature mixers provided a high-linearity low noise RF front-end, while the synthesizer integrated the loop filter to reduce the solution cost and system debug time. Fabricated in 0.18 μm CMOS, the chip achieves a less than 7.6 dB noise figure over a 900–2150 MHz L-band, while the measured sensitivity for 4.42 MS/s QPSK-3/4 mode is –91 dBm at the PCB connector. The fully integrated integer-N synthesizer operating from 2150 to 4350 MHz achieves less than 1 ℃ integrated phase error. The chip consumes about 145 mA at a 3.3 V supply with internal integrated LDOs.

Key words: direct-conversion