A detuning circuit unit for antennas of a magnetic resonance apparatus has at least two identical detuning modules that are connected in a cascade circuit and can be simultaneously activated with a control signal of a control signal source, and a circuit component to terminate a last of the detuning modules of the cascade circuit. An advantage is in the modular and cascadable use of the identical detuning modules, such that PIN diodes used as radio frequency switches are serially fed current in a first operating state and are supplied in parallel with a blocking voltage in a second operating state.