Frequency correction apparatus
US4684897A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 1984 |
| Grant date | Aug 4, 1987 |
| Priority date | — |
| Expiry date | Jan 3, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L1/026
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency correction apparatus having a delay line fed by an input signal, the frequency of such signal being corrected a predetermined amount, .DELTA.f. The delay line has a plurality of output taps regularly disposed along the line. The output taps produce a plurality of successively time-delayed signals each one having the frequency of the input signal. A switching network is included for successively coupling each one of the plurality of time-delayed signals to an output terminal of a predetermined coupling change rate related to .DELTA.f, to produce, at such output terminal, an output signal having a frequency shifted from the frequency of the input signal the predetermined amount required for the desired frequency correction. When the taps are successively coupled to the output terminal in a direction along the delay line away from the input to such line, the frequency of the output signal is equal to the frequency of the input shift shifted lower in frequency the amount .DELTA.f. On the other hand, when the taps are successively coupled in a direction towards the line input, the frequency of the output signal is shifted higher in frequency the amount .DELTA.f.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.