High frequency measuring circuit
US6161420A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1997 |
| Grant date | Dec 19, 2000 |
| Priority date | — |
| Expiry date | Nov 12, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R23/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electrical circuit and method for measuring small variations in a high frequency signal is disclosed. The circuit generates a coarse measurement of the input signal frequency and a reference signal having the same frequency as the frequency represented by the coarse measurement. The circuit measures the difference in frequency between the input signal and the reference signal, and adds the coarse measurement and the difference measurement to determine the frequency of the input signal. The circuit may be used in conjunction with a piezoelectric acoustic wave device and oscillator to provide an apparatus for accurately measuring low concentrations of a gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.