Magnetic resonance probe for operation at frequencies above self resonance

A magnetic resonance spectrometer comprising:

• a probe for at least receiving radio frequency magnetic resonance signals from a sample, the probe having a self resonance frequency above which the probe is capacitively reactive and below which the probe is inductively reactive, the probe having feed points;
• a magnetic field means for selectively generating a magnetic field adjacent the probe;
• a radio frequency transmission line for conveying the magnetic resonance signals from the probe to a radio frequency receiver means;
• and,
• an inductive matching network operatively connected between the probe and the transmission line for matching reactive and resistive impedance of the probe with the resistive impedance of the transmission line, the matching network including a first inductor connected across the feed points of the probe for resonating the probe at a frequency in excess of the self resonance frequency.

A magnetic resonance spectrometer comprising:

• a probe for at least receiving radio frequency magnetic resonance signals from a sample, the probe having feed points at which the received signals can be monitored, the probe having a self resonance frequency above which the probe is capacitively reactive and below which the probe is inductively reactive;
• a magnetic field means for selectively generating a magnetic field adjacent the probe;
• a radio frequency transmission line for conveying the magnetic resonance signals from the probe to a radio frequency receiver means;
• and,
• a pair of matching inductors connected in parallel between probe feed points and the transmission line for matching the resistive impedances of the probe and the transmission line and for cancelling the capacitive reactance of the probe at frequencies above the self resonance frequency.

A probe assembly for magnetic resonance spectrometers and the like, the probe assembly comprising:

• a probe coil having first and second feed points, the probe having a capacitive reactance above a self resonance frequency;
• a transmission line for conveying magnetic resonance signals from the probe coil to a radio frequency receiver means;
• and,
• a first inductor means connected between the feed points for cancelling the capacitive reactance of the probe to resonate the probe coil at a frequency in excess of the self resonance frequency.

A method of receiving magnetic resonance signals at a magnetic resonance frequency above a self resonance frequency of a receiving coil, the method comprising:

• positioning a receiving coil having a self resonance frequency above which the coil is capacitively reactive in a magnetic field to receive signals at the magnetic resonance frequency from a subject therein;
• connecting an inductive reactance across the coil, which inductive reactance cancels the capacitive reactance of the coil at the magnetic resonance frequency;
• and,
• operating the probe in a resonant manner above the self resonance frequency at the magnetic resonance frequency by cancelling the capacitive reactance of the probe with the inductive reactance.