Apparatus and method for compensating for the offset of a mixer
US6973293B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 13, 2002 |
| Grant date | Dec 6, 2005 |
| Priority date | — |
| Expiry date | May 1, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D3/002
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An apparatus and a method compare the output signal of a mixer in a detector with one of two input signals of the mixer, in order to compensate for the offset of a mixer or modulator. The detector determines the sign of the offset of the mixer. A compensation value is formed in an actuator unit by successive approximation. The value is transmitted to the mixer. In an advantageous embodiment of the invention, a simple phase detector (PD) is used to determine the offset sign (VZ). The above-described indirect measuring method functions with very high accuracy, even at only a very small offset. Offsets in the circuits preceding the mixer (MI1) are compensated for simultaneously. A manual or individual calibration of direct voltage offsets is therefore unnecessary.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.