Frequency counting arrangement
US4651089A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 17, 1984 |
| Grant date | Mar 17, 1987 |
| Priority date | — |
| Expiry date | Jan 17, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R23/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for determining the frequency of an input signal. The input signal and a sampling signal having a sampling frequency f.sub.s to a sampling mixer to produce a first intermediate frequency signal. The first intermediate frequency signal is applied to a detector having a response frequency bandwidth of at least f.sub.s /2 to determine whether the frequency value of the input exceeds a threshold value. The frequency value of the sampling signal is changed from among a plurality of frequency values and applied to the mixer until one of such frequency values results in a second intermediate frequency signal in a predetermined frequency range which is smaller than and lying within the detector bandwidth. The second intermediate frequency signal is applied to a frequency counter which produces a count corresponding to the second intermediate frequency. The frequency of the input signal is calculated by utilizing the count of the second intermediate frequency, the value of the sampling frequency f.sub.s and the harmonic number of the sampling mixer which produced the count of the second intermediate frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.