Tuning and matching an impedance
US6107798A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 10, 1997 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Apr 10, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H7/40
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In an MRI system including a source of a high frequency oscillating current having a required characteristic impedance and a probe having an impedance different from said required characteristic impedance and an adjustment circuit for adjusting the impedance of the probe to the required characteristic impedance there is provided an automatic circuit for matching and tuning the impedances: The circuit includes a first adjustable element and a second adjustable element arranged such that adjustment of the first and second elements causes adjustment of both a resistive component and a reactive component of the impedance and such that, over at least a part of a range, adjustment of the first element while the second element remains constant generates a change in the impedance which is substantially orthogonal to a change in the impedance obtained by adjustment of the second element while the first element remains constant and such that adjustment of the first element to a first required adjustment position and adjustment of the second element to a second required adjustment position causes the impedance of the probe to be adjusted to said required characteristic impedance. A detection …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.