Up/down conversion circuitry for radio transceiver
US7394874B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 2007 |
| Grant date | Jul 1, 2008 |
| Priority date | — |
| Expiry date | Feb 20, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/26
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A multi-channel RF receiver uses an image rejection mixer (e.g. double quadrature mixer) in the IF down conversion stage for image side band rejection (whereby use of an IF narrow band filter for image rejection may be omitted if desired) and comprises a simplified frequency synthesizer which generates both a “wandering” IF oscillator frequency and an RF oscillator frequency for the up/down conversion stages (being, for down conversion, from RF to IF and from IF to base band. The IF used for a particular RF carrier (channel) is selected so as to be both an integer (N) sub-harmonic of that RF carrier and within the operating frequency band of the image rejection mixer. Advantageously, the synthesizer comprises only one loop and one VCO, wherein the IF oscillator signal is produced from the RF oscillator signal by means of a frequency divider.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.