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 12MHz 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 6mV and 66ns 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.