Filter which tracks changing frequency of input signal
US3978416A · kind A · utility
25Cited by
4References
7Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Apr 30, 1975 |
| Grant date | Aug 31, 1976 |
| Priority date | — |
| Expiry date | Apr 30, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D3/005
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A tracking band-pass filter useful for locking onto, and passing, an input signal which changes rapidly in frequency. The filter has a frequency pass band controlled by a voltage which is derived from the output signal passed by the filter. The output signal is translated from a sine wave to a pulse wave. The period between each two successive pulses is measured by counting the cycles of a oscillator during each respective period. An inverter translates the time-representing count signal to a corresponding frequency-representing voltage which is applied to the filter to control its frequency pass band.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.