Radio frequency transmitter and method therefor
US7542519B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 29, 2005 |
| Grant date | Jun 2, 2009 |
| Priority date | — |
| Expiry date | Oct 24, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2001/0433
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An RF transmitter (10) is configured to transmit either wideband multichannel modulations or narrowband multichannel modulations in a variety of licensed frequency bands (70) using a single set of hardware. For narrowband modulations, a digital IF upconversion stage is performed so that, after upconversion to RF, image signals 74 are sufficiently displaced from the licensed frequency band (70) so as to be filtered off. For wideband modulations, no IF modulation stage occurs, and a direct upconversion takes place from baseband to RF. LO leakage is cancelled using a negative feedback loop that combines a digital DC signal with a communication signal (26, 52) prior to a direct or final analog upconversion stage (62).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.