A low-IF CMOS single-chip Bluetooth EDR transmitter with digital I/Q mismatch trimming circuit

A single-chip low-IF transmitter for the Bluetooth enhanced data rate (max. 3Mbps) was fabricated in 0.18-/spl mu/m CMOS process. A quantitative study on the relation between the VCO pulling, intermediate frequency, and the linearity of the PA shows that the 1MHz-IF is the best solution. By a digital DC offset cancellation and I/Q mismatch trimming techniques, the LO and image signal leakages are suppressed below -40dBc and -50dBc, respectively.