Error-proof decoupling of transmission and reception antennas in a nuclear magnetic resonance apparatus
US5144244A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 18, 1990 |
| Grant date | Sep 1, 1992 |
| Priority date | — |
| Expiry date | Sep 18, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/3628
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A transmission antenna for a nuclear magnetic resonance apparatus has a capacitor connected in parallel with it via at least one PIN diode, and a reception antenna for the apparatus has a capacitor connected directly in parallel with it and an inductor connected in parallel with it via a PIN diode. The PIN diodes are connected to a control voltage in a series circuit. Given a first direction of the control voltage, the PIN diodes are conductive, so that the transmission antenna is tuned to the nuclear magnetic resonant frequency due to cut-in of the capacitor and the reception antenna is detuned to the cut-in of the inductor. Given a second direction of the control voltage, the reception antenna is tuned to the nuclear magnetic resonant frequency and the transmission antenna is detuned with respect to the nuclear magnetic resonant frequency. An unwanted, local super-elevation of the RF power cannot occur with this antenna.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.