Signal analysis
US5175880A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 11, 1992 |
| Grant date | Dec 29, 1992 |
| Priority date | — |
| Expiry date | Jun 11, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R23/173
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
To analyse its spectrum, a radio signal is beat with an intermediate signal in a heterodyne circuit having a local oscillator sweeping a range of intermediate frequencies. The oscillator signal also beats with the output from a comb generator to produce signals marking intervals in its frequency sweep. The magnitude of the filtered intermediate frequency signal is measured between intervals marked by the frequency interval signals to output a frequency spectrum of the input signal. Preferably, the intermediate frequency signal is filtered in a homodyne demodulating unit employing a further local oscillator tuned to the intermediate frequency. A spectrum data display employs a memory storing the signal magnitudes at successive frequency steps at respective addresses associated with individual frequency steps. The magnitude values are assigned to their addresses by the spectrum frequency interval signals. For reading the stored data onto a two-dimensional magnitude: frequency display, control signals access the addresses and simultaneously step through the frequency dimension in the display. The signals read out from each address thereby generate magnitude values of the display which…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.