Abstract: An inductively coupled reception coil arrangement for magnetic resonance tomography, having at least two inter-nested individual coils, the outer primary coil of which serves as output coil for the inner secondary coil. The primary coil has a pre-amplifier decoupling device which closes it with high resistance.

Abstract: In a radio-frequency receiver unit for a magnetic resonance apparatus, a reception antenna is connected to an input of a noise-matched field-effect transistor preamplifier with a low input impedance. The reception antenna is connected with a detuning stage. The RF receiver unit has a noise suppression stage that can be activated when the reception antenna is detuned.

Abstract: A circularly polarizing antenna for a magnetic resonance apparatus is formed by a first linear antenna subsystem and a second antenna subsystem arranged so as to be rotated 90.degree. relative to each other. On the side of the signal terminals and each antenna subsystem has a self-contained conductor. On the side facing away from the signal terminals, the antenna subsystems have a common self-contained conductor.

Abstract: An antenna for an NMR device has a first antenna conductor structure which has two opposite end regions at which an electrical connections are respectively arranged. The antenna conductor structure has two conductor loops of equal size which are arranged essentially adjacently on one surface and which are serially connected with opposite polarity at a junction. The connections are respectively arranged at each conductor loop symmetrically to the junction.

Abstract: A circuit for detuning a resonator in a nuclear magnetic resonance imaging apparatus has an output connected to a terminal of the resonator via a high-frequency line composed of two conductors. The resonator is shortened at this terminal with a shorting capacitor that can be short-circuited for detuning the resonator. The length of the high-frequency line is shorter than one-fourth of the wavelength of a high-frequency signal having the operating frequency of the nuclear magnetic resonance imaging apparatus on the high-frequency line. For detuning the resonator the high-frequency line can be terminated at the output with a further capacitor, so that the high-frequency line acts as a short-circuit at the terminal.