Even order distortion elimination in push-pull or differential amplifiers and circuits
US7005919B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2003 |
| Grant date | Feb 28, 2006 |
| Priority date | — |
| Expiry date | Jun 28, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/541
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method for improving or eliminating second harmonic and higher even order distortion terms and balance of fundamental signals in push-pull amplifiers and other differential circuits is disclosed. A common-mode (CM) signal is generated as a sum of two complementary (out of phase) signals in a summation network. The CM signal contains even order distortion terms only, while the fundamental signal and odd order distortion terms are canceled, thus providing a correction signal that can be used to reduce even order distortion terms, by injecting the correction signal, with proper phase and amplitude, into suitable circuit nodes. For feedback, the correction signal is injected at the input of the amplifiers, for feed-forward, it's injected at the output. The correction signal can be amplified to higher levels and injected into the circuit, without affecting gain of fundamental signals; and can result in significant even order distortion improvements, and improved balance of complementary fundamental signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.