A Wideband Frequency Divider With Programmable Odd/Even Division Factors and Quadrature/Symmetrical Outputs

An injection-locked frequency divider (ILFD) with odd/even division factor and wide locking range over process and temperature variations is presented. To enhance the locking range of the frequency divider and generate accurate quadrature with 50% duty cycle outputs, a comprehensive analysis of the frequency divider to find the optimal phase sequence for two, three and five division ratios is provided. Generating quadrature and symmetrical outputs with simultaneous realization of even and odd division ratios at low power is the main challenge that is addressed in this paper as the power consumption of existing quadrature circuits is an order of magnitude higher than that of the proposed ILFD. The ILFD is designed and simulated in a 65 nm CMOS technology and the analytical results verified by the circuit simulation results. Post layout simulation results show that the locking range of the divider without any tuning is from 5.4 GHz to 8.5 GHz, 1.1 GHz to 6.1 GHz and 0.1 GHz to 5.3 GHz in divide-by-five, three and two mode for 0 dBm injection signal level, respectively. The phase deviation of the quadrature outputs for dividers is less than 1.8° and the deviation of duty cycle from 50%, is less than 0.4%.