A magnetic resonance antenna has longitudinal antenna rods in a birdcage
structure, and antenna ferrules connecting the longitudinal antenna rods
at their ends in terms of radio-frequency. The magnetic resonance antenna
has a number of radio-frequency switching elements that interrupt, in
terms of radio-frequency, at least one part of the longitudinal antenna
rod to detune the eigen-resonance frequency of the antenna with respect
to an operating magnetic resonance frequency. For this purpose, the
magnetic resonance antenna is provided with two switching lines, directed
to the radio-frequency switching elements from outside of the birdcage
structure, the switching lines having a ring line connected thereto
running annularly on or in the birdcage structure and transverse to the
longitudinal antenna rods.
