FSK modulator using IQ up-mixers and sinewave coded DACs
US7043222B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 2003 |
| Grant date | May 9, 2006 |
| Priority date | — |
| Expiry date | Oct 27, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/12
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A radio transmitter system designed using an FSK modulator with IQ up-mixers and sinewave coded digital-to-analog converters (DACs). The radio transmitter system may include a frequency shift keying (FSK) coding logic circuit coupled to the inputs of an IQ modulation and image reject up-mixer through a respective DAC and a respective low pass filter (LPF) for each the I and the Q channels. The FSK modulation scheme may employ sine and cosine signals for the I and Q channels, respectively, where the sine and cosine waves are directly coded into the DACs. The coded levels required by the DACs may be generated using current sources and may be Gray-coded. The output of the IQ modulation and image reject up-mixer may be connected to a power amplifier, which may be used to transmit the modulated RF signal via a loop antenna.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.