Matched crystal temperature compensation device
US6522212B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 18, 2000 |
| Grant date | Feb 18, 2003 |
| Priority date | — |
| Expiry date | Sep 18, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L1/028
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The invention relates to a device and a method for temperature compensation via the determination of cut-angles of a master and a slave crystal (mc, sc) employed in a master and slave oscillator (m, s). When the master and the slave oscillator (m, s) have been tuned to their center frequencies (fc_m, fc_s), then the temperature characteristic of the slave oscillator (s) is actively detuned with respect to the temperature characteristic of the master oscillator (m). In a detuned state a frequency ratio parameter (n_s) of the slave to the master output frequency (f_s/f_m) is determined and the cut-angle is determined by using this parameter (n_s) to read out the cut-angle dependent on the temperature (T) from a memory (MEM). The invention also relates to a temperature compensation device and method where two crystals of different cut-angles are used and a frequency ratio parameter is determined to determine the identity/symmetry or difference of the cut-angles. Particular useful applications of the invention are in dual-mode mobile telephones which require the use of at least two oscillators with different resonant frequencies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.