Circuitry for creating a spectral null in a differential output switching amplifier and method therefor
US6605991B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 2001 |
| Grant date | Aug 12, 2003 |
| Priority date | — |
| Expiry date | Jan 8, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/351
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A modulated signal is connected to a full bridge switching amplifier (16, 18, 28, 30) and is compensated to remove a predetermined frequency and its odd harmonics. The compensation inverts and delays (26) a signal that is connected to a first half of the full bridge and applies the delayed inverted signal to a second half of the full bridge. By delaying by an odd number of half cycles, the carrier and its odd harmonics are cancelled because the same signal exists on both sides of the full bridge output. When these two same signals are subtracted by the full bridge action, the carrier and odd harmonics are suppressed. Spectral nulls may be provided for various signal applications, not just audio, and when various types of modulation techniques are used, such as PWM and PDM.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.