Low-Power Decimation Filter Design for Multi-Standard Transceiver Applications

Recent efforts in the design of wireless RF transceivers focus on high integration and multi-standard operation. Higher integration can be obtained by using receiver architectures, such as wide-band IF with double conversion (WIF), that perform channel select filtering on-chip at baseband. Performing this baseband channel select filtering in the digital domain allows for the programmability necessary to adapt to the different channel bandwidths, sampling rates, and CNR requirements of multiple communication standards. At the back of a wide-dynamic range sigma-delta modulator, a decimation filter can select a desired channel in the presence of both strong adjacent channel interferers and quantization noise from the digitization process. A low-power decimation filter that performs channel select filtering for the GSM (European cellular) and DECT (European cordless) standards is presented. Automatic gain control is used within the filter to reduce the dynamic range and power consumption. Since the two standards have different blocking profiles and CNR Low-Power Decimation Filter Design for Multi-Standard Transceiver Applications by Carol J. Barrett Master of Science in Electrical Engineering University of California, Berkeley Professor Paul R. Gray, Advisor ii requirements, the filter can adapt to each standard and reduce its power consumption by powering down unused circuitry. For a 3.3V power supply, the filter consumes 4.4mW in GSM mode and 16.4mW in DECT mode, for input sampling rates of 12.8MHz and 44.8MHz respectively.