High-frequency interface circuit, high-frequency system and magnet resonance apparatus with a high-frequency interface circuit

A high-frequency (HF) interface circuit to direct signals transmitted by a HF generator to a connector (PR) for a HF arrangement in a transmit mode via an input (TX) of the high-frequency interface circuit and to direct received signals from the connector (PR) of the HF arrangement to a receiver system in a receive mode via an output (RX) of the high-frequency interface circuit, whereby the interface circuit comprises:

• a transmit path (SP) which links the input (TX) of the high-frequency interface circuit to the connector (PR);
• a receive path (EP) that links the connector (PR) to the output (RX) of the high-frequency interface circuit, whereby the receive path (EP) includes a first circuit (K1), wherein the first circuit (K1) comprises a first inductive element (L1), a second inductive element (L2), a first capacitive element (C1), and a second capacitive element (C2),
• whereby the first circuit (K1) includes at least a first switching element (S1) that is electro-conductive in the transmit mode and electrically insulating in the receive mode, such that the first switching element (S1) is part of both first and second parallel resonance circuits of the first circuit (K1),
• whereby, in the transmit mode, the first circuit (K1) forms the first and the second parallel resonance circuits connected in series that isolate the output (RX) of the high-frequency interface circuit from the connector (PR), wherein the second capacitive element (C2) together with the first inductive element (L1) and the first capacitive element (C1) together with the second inductive element (L2) form, respectively, the first and the second parallel resonance circuits of the first circuit (K1), and
• wherein
• in the receive mode, the first circuit (K1) includes the first and the second series resonance circuits connected in parallel, wherein the second capacitive element (C2) together with the second inductive element (L2) and the first capacitive element (C1) together with the first inductive element (L1) form, respectively, the first and the second series resonance circuits of the first circuit (K1), and
• wherein the receive path (EP) includes a second grounding switching element (S2) that is electro-conductive in the transmit mode and electrically insulating in the receive mode, and
• wherein the receive path (EP) includes a second circuit (K2) that is connected to the first circuit (K1) in series, whereby the second switching element (S2) is part of the second circuit (K2), and whereby the second circuit (K2) forms a low pass filter in the receive mode and a third parallel resonance circuit in the transmit mode.