Claims
- 1. A device for adjusting a nuclear magnetic resonance apparatus having an antenna comprising:
- a first length of high frequency line connected to said apparatus's emissive/receptive means;
- an antenna tuning circuit connected to said first length of high frequency line for tuning said antenna;
- a sensor interposed between said apparatus's emissive/receptive means and said tuning circuit for measuring the amount of tuning;
- measuring means coupled to said sensor for measuring the real part of admittance by multiplying the antenna signal by a square signal synchronous with the antenna signal and for measuring the phase shift between the current and voltage of the antenna signal; and
- a second length of high frequency line coupled to said tuning circuit on one end and said antenna at the other end.
- 2. The device as claimed in claim 1 wherein the means for measuring the phase shift includes means for phase shifting a signal that is proportional to the current and for multiplying this phase shifted signal by a square wave signal synchronous with the antenna signal.
- 3. The device as claimed in claim 1 wherein the high frequency line is a coaxial cable whose characteristic impedance is equal to 50 ohms.
- 4. The device as claimed in claim 1 wherein the tuning circuit is a .pi. circuit with two adjustable capacities in parallel at the terminals of a fixed inductance.
- 5. The device as claimed in claim 1 wherein the sensor includes a coupling circuit for picking up a signal proportional to the current and a divider bridge for picking up a signal proportional to the voltage of the antenna signal.
Priority Claims (1)
Number |
Date |
Country |
Kind |
85 17722 |
Nov 1985 |
FRX |
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Parent Case Info
This application is a continuation of application Ser. No. 935,391, filed on Nov. 26, 1986, now abandoned.
US Referenced Citations (8)
Foreign Referenced Citations (6)
Number |
Date |
Country |
0047065 |
Mar 1982 |
EPX |
0073614 |
Mar 1983 |
EPX |
0132338 |
May 1985 |
EPX |
0142760 |
May 1985 |
EPX |
0145915 |
May 1985 |
EPX |
8400214 |
Jan 1984 |
WOX |
Non-Patent Literature Citations (2)
Entry |
Journal of Physics E-Scientific Instruments, vol. 14, No. 6, Jun. 1981, pp. 700-701, The Institute of Physics, London, GB; M. Peric et al.: "Simple RF Matching for NMR Coils in Endor Spectrometers". |
Cross, V. R. et al., "Single Coil Probe with Transmission-Line Tuning for Nuclear Magnetic Double Resonance". |
Continuations (1)
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Number |
Date |
Country |
Parent |
935391 |
Nov 1986 |
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