Method and apparatus for increasing the sweep rate of a linearly swept frequency oscillator
US4336511A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 1979 |
| Grant date | Jun 22, 1982 |
| Priority date | — |
| Expiry date | Apr 9, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B2200/0092
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The sweep rate of a linearly swept frequency generator is increased while maintaining strict linearity by artificially increasing the number of zero axis crossings of the output signal from a linearly swept voltage controlled oscillator over those that would naturally occur during a linear sweep. This permits an increased sampling rate which, in turn, permits the oscillator sweep rate to be increased without loss of accuracy. Increasing the number of zero axis crossings is accomplished by introducing phase shifts in the output of the oscillator at calculated sampling times with phase shifting being accomplished indirectly by heterodyning the swept oscillator output with the output from a fixed oscillator whose output signal is phase shifted by discrete amounts during the frequency sweep. Only a small number of phase shifts need be introduced due to the discovery of certain symmetries of phase when sweeping through a frequency range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.