System and method for I-Q mismatch compensation in a low IF or zero IF receiver
US6785529B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2002 |
| Grant date | Aug 31, 2004 |
| Priority date | — |
| Expiry date | Sep 27, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0024
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A compensation circuit to correct for mismatch in a quadrature receiver comprises first and second mixers to receive a radio frequency (RF) modulated signal. One mixer receives an I local oscillator signal while the second mixer receives a Q local oscillator signal wherein the I and Q local oscillators have frequencies that are substantially identical. The output of the first and second mixers are coupled to first and second filters, respectively, which generate the I and Q output signals, respectively. Inherent circuit mismatch generate gain and/or phase errors that result in mismatch in the I and Q output signals. A correction circuit automatically applies a correction factor to at least one of the I and Q output signals to correct the gain and/or phase error by applying a multiplication factor to at least one of the I and Q output signals to thereby generate a corrected signal. The correction factors must be determined on a unit by unit basis. Testing in the final stages of factory assembly may be used to determine the value of the correction factor. The correction factor may be stored in a memory of the wireless communication device and used thereafter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.