Integrated oscillator and radio telephone using such an oscillator
US5937340A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1997 |
| Grant date | Aug 10, 1999 |
| Priority date | — |
| Expiry date | Oct 7, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B2202/05
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The invention relates to an oscillator OSC intended to provide an output signal having a frequency which is variable as a function of a tuning voltage Vtun. The oscillator OSC includes a passive part having two series-arranged variable capacitances Cs, biased by the tuning voltage Vtun, and connected to a power supply VCC via two inductances Lext, and an active part having a first transistor T1 and a second transistor T2 whose collectors are connected to the output terminals C1 and C2 of the passive part, the base of one transistor being connected to the collector of the other transistor via a coupling capacitor Cfb. According to the invention, the passive part includes two high-pass filters, each being inserted between one of the output terminals S1 or S2 and one of the variable capacitances Cs, which allows a reduction of the active part's sensitivity to low-frequency noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.