Digital spur calibration of multi-modulus fractional frequency LO divider utilizing most correlated comparison algorithm
In this paper, a digital calibration scheme is proposed to correct phase mismatch among the multi-phase inputs of the pulse combiner to suppress the spurs at the output of the multi-modulus fractional frequency local oscillator divider. Compared with the conventional design, the proposed calibration scheme utilizes most correlated comparison algorithm to reduce convergence time significantly. The proposed calibration scheme is implemented by digital logic, and simulation results show that for all division ratios at maximum output frequency of 6 GHz, average convergence time is reduced by at least 68% compared to the conventional design.