Electro-optic spectrum analyzer
US5481183A · kind A · utility
Inventors
Key dates
| Filing date | Apr 19, 1995 |
| Grant date | Jan 2, 1996 |
| Priority date | — |
| Expiry date | Apr 19, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R23/17
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A broadband spectrum analyzer for radio frequency and microwave signals. The signal to be analyzed modulates an optical laser beam through an electro-optic modulator. The resultant modulated beam thus comprises light at a frequency (carrier frequency) corresponding to the wavelength of the laser beam and frequencies close to the carrier frequency corresponding to the frequencies representing the modulating signal. The modulated beam is expanded to produce a beam with light traveling in a large number of directions within a narrow angle. The expanded beam illuminates the aperture of an etalon. The etalon functions as an optical filter passing only portions of the beam which enter the etalon at an angle such that the distance traveled by the light within the etalon equals an integral number of wavelengths. Thus, different frequencies pass through the etalon at different angles. The output from the etalon is collected by a video camera for display and interpretation. This new approach allows a larger instantaneous bandwidths to be analyzed than is possible with current systems, and allows a simple video camera to be used for observation of the spectrum of interest.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.