Local oscillator for generating an HF signal for direct mixing by using avalanche photodiodes
US6950639B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 23, 2001 |
| Grant date | Sep 27, 2005 |
| Priority date | — |
| Expiry date | Jul 12, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/36
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A local oscillator for use in an optoelectronic distance measurement system for generating a narrow-band HF signal for direct signal mixing with a reception signal generated by an avalanche photodiode (2) from a light signal impinging on the latter, with the depletion layer capacitance (CAPD) of the avalanche photodiode (2), which varies due to different influences and specimen scatter, is incorporated, as an element which (co-)determines the oscillator frequency, in a controllable HF resonant circuit whose HF resonant frequency is determined, for example, by the adjustable divider ratio of a PLL-circuit (1) which is acted upon by a phase-locked reference oscillator (6) and which controls the capacitance (C) of a capacitance diode (3) connected in parallel with the depletion layer capacitance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.