Device and method for adjusting a radiofrequency antenna of a nuclear magnetic resonance apparatus
US4950993A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1989 |
| Grant date | Aug 21, 1990 |
| Priority date | — |
| Expiry date | Jan 25, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device and method are provided for adjusting a radiofrequency antenna of a nuclear magnetic resonance apparatus. In the invention, using capacities preset in the factory, the antenna detuning of an NMR apparatus is limited to a range such that the standing wave rate of a high frequency line which conveys the radiofrequency signal is limited. This line is cut and, at a short distance, a tuning adjustment circuit is inserted. This circuit may be automated: the electric adjustment motors, thus spaced away, do not disturb the magnetic fields of the apparatus. By measuring the real part of the admittance at the input of the adjustment circuit and the phase shift between voltage and current this circuit can be adjusted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.