Patent ID: 6794874
Filing Date: 2004-09-21
Classification: G01R

Abstract:
A multiple tuning circuit for use in an NMR spectrometer, said multiple tuning circuit comprising:a sample coil having ends A and B, said end A being grounded via a first capacitive element, said end B being grounded via a second capacitive element; a first inductor having a first end connected with the end A of said sample coil via a third capacitive element, said first inductor having a second end grounded; a second inductor having a first end connected with the end B of said sample coil via a fourth capacitive element, said second inductor having a second end grounded; a first set of matching circuit and tuning circuit for supplying first RF to said sample coil; and a second set of matching circuit and tuning circuit for supplying second RF to said sample coil, wherein said sample coil, first inductor, second inductor, first capacitive element, second capacitive element, third capacitive element, and fourth capacitive element together form a balanced resonant circuit where voltage amplitude becomes zero near a center point of the sample coil.