Phase Noise Reduction in High Speed Frequency Divider

Maximum operating frequency, phase noise characteristics close to output carrier frequency and power consumption during operation are major parameters of a frequency divider. Since these parameters are interrelated, design optimization involves tradeoffs among them. A new differential D-latch based topology for a low phase noise frequency divider for cellular transceivers is presented. An optimization process for the design of frequency divider is given and various phenomena that dominate phase noise and high frequency behavior of the frequency dividers are discussed. The proposed divider designed using 65 nm CMOS has a maximum input frequency of 11.8 GHz with phase noise level of 153.3 dBc/Hz at an offset of 20 MHz. It consumes 11 mA average current while operating at a nominal frequency of 8 GHz