Fast coarse tuning for frequency synthesizer
AssigneeQUALCOMM Incorporated
InventorsYuehai JIN, Xinhua CHEN
Life of this patent
Estimating the term…
Abstract
A coarse tuning synthesizer for wireless communication includes a digital control unit, a digital-to-analog converter, and a comparator. The digital control unit includes an output node coupled to a first input node of a VCO (voltage controlled oscillator). The digital-to-analog converter includes a first node coupled to the first input node of the VCO. The comparator includes an output node coupled to an input node of the digital control unit. The comparator also includes a first input node coupled to a second node of the digital-to-analog converter and a second input node coupled to an output node of the VCO.
Claims21
A coarse tuning method based on delta modulation comprising:
- comparing a first voltage, based on a digital tuning code, to a closed loop tuning voltage from a low pass filter of a synthesizer;
- digitally integrating an output generated from the comparing;
- and
- updating the digital tuning code based at least in part on the integrating to change a coarse tuning frequency range of a VCO (voltage controlled oscillator), in which a final updated digital tuning code corresponds to a coarse tuning frequency range closest to a target frequency.
A coarse tuning synthesizer for wireless communication comprising:
- a digital control unit having an output node coupled to a first input node of a VCO (voltage controlled oscillator);
- a digital-to-analog converter having a first node coupled to the first input node of the VCO;
- and
- a comparator comprising an output node coupled to an input node of the digital control unit, a first input node coupled to a second node of the digital-to-analog converter and a second input node coupled to an output node of the VCO.
A coarse tuning synthesizer for wireless communication comprising:
- means for generating a digital tuning code, the digital tuning code generating means coupled to a first input node of a VCO (voltage controlled oscillator);
- a digital-to-analog converter having a first node coupled to the first input node of the VCO;
- and
- a comparator comprising an output node coupled to the digital tuning code generating means, a first input node coupled to a second node of the digital-to-analog converter and a second input node coupled to an output node of the VCO.
Dependencies are inferred from the claim text.