Dual-loop transmit noise cancellation
US8880010B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 30, 2009 |
| Grant date | Nov 4, 2014 |
| Priority date | — |
| Expiry date | May 28, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/0475
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A transmitter circuit is described. The transmitter circuit includes a first local oscillator that generates a first frequency equal to a duplex frequency. The transmitter circuit also includes a second local oscillator that generates a second frequency equal to a receive frequency. The transmitter circuit further includes a first mixer that combines the first frequency with a first input signal. The transmitter circuit also includes a first feedback loop. The first feedback loop includes a second mixer that combines the second frequency with a transmit signal and a first filter and a first adder that combines an output of the first mixer with an output of the first filter. The transmitter circuit also includes a third local oscillator that generates a third frequency equal to the receive frequency. The transmitter circuit further includes a third mixer that combines the third frequency with an output of the first adder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.