Feed forward cancellation amplifier utilizing dynamic vector control
US5508657A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 30, 1995 |
| Grant date | Apr 16, 1996 |
| Priority date | — |
| Expiry date | Jan 30, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2201/3212
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A feed forward cancellation amplifier system for amplifying radio frequency telephony signals, including a main amplifier, an error correction circuit producing a message error signal, an error amplifier for producing an amplified message error signal that is then subtracted from the amplified and distorted message signal output of the main amplifier prior to a final output circuit, a negative feedback circuit responsive to a test signal for compensating and minimizing variation or drift in the operation of the error amplifier, the error correction circuit including a vector modulator responsive to modified quadrature vector components of the message error signal for producing a single voltage vector error signal, and the negative feedback circuit including an I & Q network for modifying the quadrature vector components of the error signal in the error correction circuit. The preferred form of the invention utilizes PIN diodes to provide voltage controlled attenuators in the vector modulator. An auxiliary negative feedback circuit is also provided for compensating variation or drift of the main amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.