HIGH-FREQUENCY INTERFACE CIRCUIT, HIGH-FREQUENCY SYSTEM AND MAGNET RESONANCE APPARATUS WITH A HIGH-FREQUENCY INTERFACE CIRCUIT

• US 20180038925A1
• Filed: 08/04/2017
• Published: 02/08/2018
• Est. Priority Date: 08/04/2016
• Status: Active Grant

• Current Assignee: Bruker Biospin GMBH (Bruker Corporation)
• Original Assignee: Bruker Biospin GMBH (Bruker Corporation)
• Inventors: MAIXNER, Michael
• Granted Patent: US 10,502,798 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 33/36 Electrical details, e.g. matching or coupling of the coil to the receiver
• CPC Class Codes: G01R 33/3607 RF waveform generators, e.g. frequency generators, amplitude-, frequency- or phase modulators or shifters, pulse programmers, digital to analog converters for the RF signal, means for filtering or attenuating of the RF signal
• CPC Class Codes: G01R 33/3621 NMR receivers or demodulators, e.g. preamplifiers, means for frequency modulation of the MR signal using a digital down converter, means for analog to digital conversion [ADC] or for filtering or processing of the MR signal such as bandpass filtering, resampling, decimation or interpolation
• CPC Class Codes: G01R 33/3628 Tuning/matching of the transmit/receive coil
• CPC Class Codes: G01R 33/3642 Mutual coupling or decoupling of multiple coils, e.g. decoupling of a receive coil from a transmission coil, or intentional coupling of RF coils, e.g. for RF magnetic field amplification
• CPC Class Codes: G01R 33/3657 Decoupling of multiple RF coils wherein the multiple RF coils do not have the same function in MR, e.g. decoupling of a transmission coil from a receive coil

Abstract

A high-frequency interface circuit to direct transmitted signals to a connector (PR) for a HF arrangement in a transmit mode via an input (TX) of the high-frequency interface circuit and received signals from the connector (PR) to a receiver system in a receive mode via an output (RX) of the high-frequency interface circuit is presented. The circuit includes a transmit path (SP) linking the input (TX) to the connector (PR) and a receive path (EP) linking the connector (PR) to the output (RX). The receive path (EP) includes a first circuit (K1), with at least a first switching element (S1) that is electro-conductive in transmit mode and is electrically insulating in receive mode, connected to the connector (PR). In transmit mode, the first circuit (K1) forms two parallel resonance circuits connected in series, while in receive mode, the first circuit (K1) includes two series resonance circuits connected in parallel.

Claims

1. 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),

whereby the first circuit (K1) includes at least a first switching element (S1) that is electro-conductive in transmit mode and electrically insulating in receive mode,

whereby, in transmit mode, the first circuit (K1) forms first and second parallel resonance circuits connected in series that isolate the output (RX) of the high-frequency interface circuit from the connector (PR);

wherein

in receive mode, the first circuit (K1) includes first and second series resonance circuits connected in parallel.

2. The high-frequency interface circuit as claimed in claim 1, 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),

in transmit mode, 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 second parallel resonance circuits of the first circuit (K1) and

the first switching element (S1) is part of both the first and the second parallel resonance circuit and

in receive mode, 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 circuit of the first circuit (K1).

3. The high-frequency interface circuit as claimed in claim 2, wherein the receive path (EP) includes a second grounding switching element (S2) that is electro-conductive in transmit mode and electrically insulating in receive mode.

4. The high-frequency interface circuit as claimed in claim 3, wherein the second switching element (S2) in the receive path (EP) is positioned directly before the output (RX) of the high-frequency interface circuit.

5. The high-frequency interface circuit as claimed in claim 3, 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 receive mode and a third parallel resonance circuit in transmit mode.

6. The high-frequency interface circuit as claimed in claim 5, wherein the second circuit (K2) includes a third inductive element (L3) and a third capacitive element (C3) that together form part of the third parallel resonance circuit in transmit mode and part of the low pass filter in receive mode.

7. The high-frequency interface circuit as claimed in claim 5, wherein the second circuit (K2) additionally includes a fourth capacitive element (C4) and a third grounding switching element (S3) that is electro-conductive in transmit mode and electrically insulating in receive mode, whereby, in transmit mode, the fourth capacitive element (C4) is part of the third parallel resonance circuit.

8. The high-frequency interface circuit as claimed in claim 5, wherein the second circuit (K2) additionally includes a fifth capacitive element (C5) that is located parallel to the second switching element (S2) and is part of the low pass filter in receive mode.

9. The high-frequency interface circuit as claimed in claim 6, wherein the inductance of the third inductive element (L3) is half as big as the inductance of the first inductive element (L1) or the second inductive element (L2).

10. The high-frequency interface circuit as claimed in claim 1, wherein the transmit path (SP) includes an input-isolator circuit with a fourth switching element (S4) that is electro-conductive in transmit mode and electrically insulating in receive mode.

11. The high-frequency interface circuit as claimed in claim 10, wherein the input-isolator circuit is a HF filter in transmit mode.

12. A high-frequency system with a HF generator to generate HF signals, a HF arrangement to send and detect HF signals, a receiver system to process the detected HF signals and a high-frequency interface circuit as claimed in claim 1, whereby the HF generator is connected to the input (TX) of the high-frequency interface circuit, the receiver system is connected to the output (RX), and the HF arrangement is connected to the connector (PR) of the high-frequency interface circuit.

13. A magnetic resonance apparatus with a HF arrangement to excite magnetic resonances and to receive MR signals and with a high-frequency interface circuit as claimed in claim 1.

14. The magnetic resonance apparatus as claimed in claim 13, wherein the HF arrangement is an MR probe.

15. The use of a high-frequency interface circuit as claimed in claim 1 in a magnetic resonance apparatus for multi-resonance MR measurements.

16. The high-frequency interface circuit as claimed in claim 1, wherein the receive path (EP) includes a second grounding switching element (S2) that is electro-conductive in transmit mode and electrically insulating in receive mode.

17. The high-frequency interface circuit as claimed in claim 4, 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 receive mode and a third parallel resonance circuit in transmit mode.

18. The high-frequency interface circuit as claimed in claim 6, wherein the second circuit (K2) additionally includes a fourth capacitive element (C4) and a third grounding switching element (S3) that is electro-conductive in transmit mode and electrically insulating in receive mode, whereby, in transmit mode, the fourth capacitive element (C4) is part of the third parallel resonance circuit.

19. The high-frequency interface circuit as claimed in claim 6, wherein the second circuit (K2) additionally includes a fifth capacitive element (C5) that is located parallel to the second switching element (S2) and is part of the low pass filter in receive mode.

20. The high-frequency interface circuit as claimed in claim 7, wherein the second circuit (K2) additionally includes a fifth capacitive element (C5) that is located parallel to the second switching element (S2) and is part of the low pass filter in receive mode.

21. The high-frequency interface circuit as claimed in claim 7, wherein the inductance of the third inductive element (L3) is half as big as the inductance of the first inductive element (L1) or the second inductive element (L2).

22. The high-frequency interface circuit as claimed in claim 8, wherein the inductance of the third inductive element (L3) is half as big as the inductance of the first inductive element (L1) or the second inductive element (L2).