A CMOS baseband complex bandpass filter with a new Automatic tuning method for PHS applications

This paper presents a baseband complex bandpass filter for PHS applications with a new automatic tuning method. The full-CMOS PHS transceiver is implemented by adopting the Low-IF architecture to overcome the DC-offset problems. To meet the adjacent channel selectivity (ACS) performance, the 3rd-order Chebyshev complex bandpass filter is designed as the baseband channel-select filter. The new corner frequency tuning method is proposed to compensate the process variation. This method can reduce the noise level due to MOS switches. The filter was fabricated using a 0.35 mum CMOS process, and the power consumption is 12 mW.