Fast acquisition frequency synthesizer with the multiple phase detectors

The authors propose a frequency synthesizer which is implemented by deploying a multiple phase detector scheme, and by adding a bias voltage corresponding to desired frequency to the input of a voltage controlled oscillator (VCO) and resetting each divider. One can obtain a fast acquisition time within one cycle of the reference frequency. The acquisition time which is generated by the variation of bias voltage in the VCO due to temperature characteristics can also be minimized by using the proposed multiple phase detectors. The authors have compared the acquisition time of the new frequency synthesizer with a conventional frequency synthesizer and a significant improvement was obtained. The performance was verified by experiments