Dual mode class D amplifiers
US6768376B2 · kind B2 · utility
12Cited by
3References
4Claims
0Family size
Inventors
Key dates
| Filing date | May 6, 2003 |
| Grant date | Jul 27, 2004 |
| Priority date | — |
| Expiry date | May 6, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/2171
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Pulse width modulated (“Class D”) amplifiers and controllers switching in the 50 khz to 2 MHz range generate harmonics that interfere with AM radio reception. This interference has precluded wide spread acceptance of class D amplifiers in products that include an AM radio. The amplifier described here uses a a harmonic avoidance modulator when operating with an AM radio to avoid generating harmonics at the receiver selected frequency or the intermediate (IF) frequency thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.