Transmitter for wireless applications incorporation spectral emission shaping sigma delta modulator
US7787563B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 2005 |
| Grant date | Aug 31, 2010 |
| Priority date | — |
| Expiry date | Feb 17, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/3042
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A transmitter employing a sigma delta modulator having a noise transfer function adapted to shift quantization noise outside at least one frequency band of interest. A technique is presented to synthesize the controllers within a single-loop sigma delta modulator such that the noise transfer function can be chosen arbitrarily from a family of functions satisfying certain conditions. Using the novel modulator design technique, polar and Cartesian (i.e. quadrature) transmitter structures are supported. A transmitter employing polar transmit modulation is presented that shapes the spectral emissions of the digitally-controlled power amplifier such that they are significantly and sufficiently attenuated in one or more desired frequency bands. Similarly, a transmitter employing Cartesian transmit modulation is presented that shapes the spectral emissions of a hybrid power amplifier such that they are significantly and sufficiently attenuated in one or more desired frequency bands.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.