Patent ID: 8148986

Claim:
An antenna system for exciting and/or detecting a magnetic resonance in an object to be examined that is exposed to a main magnetic field that orients spins of the object in a desired longitudinal direction (z), with at least a first antenna structure containing a plurality of conducting sections that are each designed to conduct high-frequency alternating current at a magnetic resonance frequency in the range of approximately 1 MHz to 1 GHz and that extend from a common vertex area spreading out like claws to a base area in order to surround like a helmet a part of the object lo be examined and containing a volume of interest, wherein each conducting section is designed as an antenna line for conducting a guided wave propagating in TEM mode or in a quasi TEM mode in electromagnetic coupling with the spins of the object to be examined which is to be surrounded; wherein an electrical length and terminations of the antenna lines of the first antenna structure are selected in such a manner that standing waves at the frequency of the magnetic resonance occur in the antenna lines; and wherein the electrical length and termination of each antenna line of the first antenna structure is dimensioned such that at the magnetic resonance frequency the magnitude of the alternating current on the antenna line continuously increases from the vertex area to the base area or from both ends towards the middle thereof.