A low power multi-mode baseband for direct-conversion WLAN transceiver and DVB-H

A multi-mode transceiver baseband RFIC compliant with IEEE 802.11a/b/g and DVB-H is presented. The receiver filter has three corner frequency designed for WLAN and DVB-H respectively and the VGA provides 50 dB gain range with a step of 0.8 dB; the transmitter filter provides 12 MHz bandwidth and the VGA covers 24 dB gain range in 1.6-dB steps. In addition, the calibration of filter is reported to achieve the bandwidth accuracy of 3%. A DC offset cancellation circuit is also introduced to remove the offset from layout and self-mixing, and the remaining offset voltage and setting time are only 6 mV and 66 ns respectively. The chip consumes 21.9 mA in RX mode, and 9.1 mA (only for one path) in TX mode from 2.85-V supply. The RFIC was implemented in a 47-GHz SiGe technology with 2.2-mm² die size.