Detuning a MRT receive antenna

1. An arrangement for detuning a receive antenna, the arrangement comprising:

a receive antenna having at least one first capacitance, wherein radiofrequency signals from a magnetic resonance examination are receivable by way of the receive antenna;

a switchable detuning circuit that contains the at least one first capacitance switched to form an oscillating circuit and a first inductance; and

a switching device comprising one or more transistors, a first connection point, and a second connection point configured to deliver a voltage between the first connection point and the second connection point, wherein at least one transistor of the one or more transistors is a field-effect transistor having a gate terminal, a source terminal, and a drain terminal, and wherein the gate terminal is connected to the first connection point,

wherein the switching device is configured to switch the oscillating circuit to a high impedance level with aid of the one or more transistors on delivery of a positive voltage to the first connection point so as to prevent a radiofrequency signal from being received by way of the receive antenna.

2. The arrangement of claim 1 , wherein the switching device further comprises at least one diode.

3. The arrangement of claim 1 , wherein the field-effect transistor is a metal-oxide-semiconductor field-effect transistor.

4. The arrangement of claim 1 , wherein the field-effect transistor is a field-effect transistor based on III-V semiconductors.

5. The arrangement of claim 1 , wherein the field-effect transistor is a field-effect transistor based on gallium nitride.

6. The arrangement of claim 1 , wherein the switching device has a diode connected to the gate terminal and the first connection point in a forward direction, and connected to the source terminal in a reverse direction.

7. The arrangement of claim 1 , wherein the switching device has a connection between the second connection point and the drain terminal.

8. The arrangement of claim 1 , wherein the field-effect transistor exhibits a behavior analogous to an inverse diode.

9. The arrangement of claim 1 , wherein at least one transistor of the one or more transistors is a bipolar transistor.

10. The arrangement of claim 9 , wherein the bipolar transistor comprises an insulated gate electrode.

11. The arrangement of claim 1 , wherein the switching device comprises at least two transistors connected in series.

12. The arrangement of claim 1 , wherein the switching device comprises at least one resistance for current limiting.

13. The arrangement of claim 1 , wherein the switching device comprises at least one inductance for current limiting and/or for filtering.

14. The arrangement of claim 1 , wherein the receive antenna is a loop antenna and/or dipole antenna.

15. A magnetic resonance coil comprising:

an arrangement for detuning a receive antenna, the arrangement comprising:

a receive antenna having at least one first capacitance, wherein radiofrequency signals from a magnetic resonance examination are receivable by way of the receive antenna;

a switchable detuning circuit that contains the at least one first capacitance switched to form an oscillating circuit and a first inductance; and

a switching device comprising one or more transistors, a first connection point, and a second connection point configured to deliver a voltage between the first connection point and the second connection point, wherein at least one transistor of the one or more transistors is a field-effect transistor having a gate terminal, a source terminal, and a drain terminal, and wherein the gate terminal is connected to the first connection point,

wherein the switching device is configured to switch the oscillating circuit to a high impedance level with aid of the one or more transistors on delivery of a positive voltage to the first connection point so as to prevent a radiofrequency signal from being received by way of the receive antenna.

16. The magnetic resonance coil of claim 15 , wherein the magnetic resonance coil is a local coil.

17. A magnetic resonance device comprising:

at least one magnetic resonance coil, the magnetic resonance coil comprising:

an arrangement for detuning a receive antenna, the arrangement comprising:

a receive antenna having at least one first capacitance, wherein radiofrequency signals from a magnetic resonance examination are receivable by way of the receive antenna;

a switchable detuning circuit that contains the at least one first capacitance switched to form an oscillating circuit and a first inductance; and

a switching device comprising one or more transistors, a first connection point, and a second connection point configured to deliver a voltage between the first connection point and the second connection point, wherein at least one transistor of the one or more transistors is a field-effect transistor having a gate terminal, a source terminal, and a drain terminal, and wherein the gate terminal is connected to the first connection point,

wherein the switching device is configured to switch the oscillating circuit to a high impedance level with aid of the one or more transistors on delivery of a positive voltage to the first connection point so as to prevent a radiofrequency signal from being received by way of the receive antenna.

18. The magnetic resonance device of claim 17 , wherein the at least one magnetic resonance coil is a local coil.