Circulator

A magnetic resonance antenna device for a magnetic resonance apparatus that produces an external magnetic field during operation thereof, said antenna device comprising:

• an antenna configured to transmit radio-frequency signals or receive magnetic resonance signals, said antenna comprising at least one antenna terminal;
• an amplifier that generates signals for supply to said at least one antenna terminal configured to activate said antenna;
• a circulator connected between said amplifier and said at least one antenna terminal that discharges power reflected by said antenna into a power dump connected to the circulator;
• and
• said circulator comprising a flat ferrite structure comprising a first terminal adapted for connection to an amplifier and a second terminal adapted for connection to an antenna, said ferrite structure being configured to interact with an operating field, and when said operating field is optimum, to relay reflection-free signals from said amplifier to said antenna, and a field conductor device that amplifiers or attenuates said external magnetic field, said field conductor device being located relative to said flat ferrite structure and generating said operating field, from said external magnetic field, so as to proceed perpendicularly through said ferrite structure, said field conductor device comprising no permanent magnet and being configured to interact with said external magnetic field at any arbitrary location within said external magnetic field to make said operating field optimum for said ferrite structure.

A magnetic resonance apparatus comprising:

• a magnetic resonance data acquisition device comprising an antenna that radiates radio-frequency signals or receives magnetic resonance signals, said antenna having at least one antenna terminal, said magnetic resonance data acquisition device producing an external magnetic field during operation thereof;
• an amplifier that generates signals for supply to said at least one antenna terminal configured to activate said antenna;
• a circulator connected between said amplifier and said at least one antenna terminal that discharges power reflected by said antenna into a power dump connected to the circulator;
• and
• said circulator comprising a flat ferrite structure comprising a first terminal adapted for connection to an amplifier and a second terminal adapted for connection to an antenna, said ferrite structure being configured to interact with an operating field, and when said operating field is optimum, to relay reflection-free signals from said amplifier to said antenna, and a field conductor device that amplifiers or attenuates said external magnetic field, said field conductor device being located relative to said flat ferrite structure and generating said an operating field, from said external magnetic field, so as to proceed perpendicularly through said ferrite structure, said field conductor device comprising no permanent magnet and being configured to interact with said external magnetic field at any arbitrary location within said external magnetic field to make said operating field optimum for said ferrite structure.