Serrodyne modulator
US5063361A · kind A · utility
8Cited by
1References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1990 |
| Grant date | Nov 5, 1991 |
| Priority date | — |
| Expiry date | Dec 21, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B21/00
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A direct digital synthesizer (DDS) includes a phase accumulator which generates phase words periodically and means for changing the phase of an RF signal. In a preferred embodiment, a DDS includes a pair of phase shifter channels having inputs and outputs coupled in parallel by make before break RF switches. The use of the dual phase shifter channels and make before break RF switches provides relatively smooth phase advance while eliminating fly-back transitions. This arrangement reduces excessive noise power in the output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.