Local oscillator with non-harmonic ratio between oscillator and RF frequencies using XOR operation
US8121214B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 2007 |
| Grant date | Feb 21, 2012 |
| Priority date | — |
| Expiry date | Apr 6, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B21/02
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A novel and useful apparatus for and method of local oscillator (LO) generation with non-integer multiplication ratio between the local oscillator and RF frequencies. The LO generation schemes presented are operative to generate I and Q square waves at a designated frequency while avoiding the well known issue of harmonic pulling. A synthesizer provides 4/3 the desired frequency fRF. This frequency is divided by two to obtain in-phase and quadrature square waves at ⅔ fRF. The in-phase signal is divided by two again to obtain in-phase and quadrature square waves at ⅓ fRF. The signals are then logically combined using XOR operations to obtain I and Q branch signals containing spectral spurs. Since the spurs are located in non-disturbing bands, they can be filtered out resulting in the desired output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.