Abstract:
A resonator for use in a magnetic resonance imaging apparatus for transmitting and receiving high frequency signals is formed by a combination of two antenna sub-systems, which generate respective magnetic fields which are perpendicular to each other, with the currents in the sub-system being phase-shifted by 90.degree. relative to each other, and each sub-system includes a capacitance which defines the resonant frequency. Each of the sub-systems forms a current loop, the current loops containing a common current network and a common base plate, which serves as a return path for both current loops. The junctions of the current network are connected via the resonant capacitances to the base plate, which consists of electrically conductive material. A circularly polarizing resonator is achieved for the transversal, fundamental field of the imaging apparatus, with the resonator also being capable of use as a surface resonator if the spacing between the current network and the base plate is small.
Abstract:
A transmission amplifier is provided for amplifying the signal in a wire-free transmission system. The transmission amplifier includes a pre-amplifier stage and an amplifier output stage that is coupled to the pre-amplifier stage. The amplifier output stage is configured with gate components and is configured to provide a signal fed in as an amplified output signal on the output side.
Abstract:
A magnetic resonance imaging (MRI) system connection for a magnetic resonance imaging system, such as for an MRI local coil and/or patient couch, is provided. The MRI system connection is embodied with devices for a field-coupled transmission of signals.
Abstract:
A transmission amplifier is provided for amplifying the signal in a wire-free transmission system. The transmission amplifier includes a pre-amplifier stage and an amplifier output stage that is coupled to the pre-amplifier stage. The amplifier output stage is configured with gate components and is configured to provide a signal fed in as an amplified output signal on the output side.
Abstract:
A line with a standing wave trap for a magnetic resonance tomograph, and a patient couch and a magnetic resonance tomograph with the line are provided. The line includes a carrier material, a first conductor track that extends along the carrier material in the carrier material or on the carrier material, and a first conductor loop. The first conductor loop is arranged on or in the carrier material. The first conductor loop has a signal coupling to the first conductor track. The first conductor loop has a first interruption that is bridged with a first capacitance.
Abstract:
A device for damping a standing wave on a waveguide carrying a signal is provided. The device includes at least one pair of an impedance-up-transforming and an impedance-down-transforming Boucherot bridge is connected into the waveguide. The two Boucherot bridges bring about locally increased impedances and inductance values, with the result that a significantly improved standing wave suppression or damping is obtained. The down-transforming Boucherot bridge is connected directly behind the up-transforming bridge, with the result that down-transformation to the original impedance of the waveguide again can be carried out and a signal reflection can thus be avoided.
Abstract:
A transmitting apparatus for transmitting a frequency-modulated signal is provided. The transmitting apparatus includes a pilot tone generation device for generating a pilot tone. The transmitting apparatus also includes a modulation device for obtaining the generated pilot tone and a modulating useful signal and for generating a frequency-modulated signal based on a combination of the generated pilot tone and the modulating useful signal. The generated pilot tone has a frequency outside a frequency range of the modulating useful signal in order to vary a frequency range of the frequency-modulated signal.
Abstract:
An arrangement for processing a non-symmetrical signal includes an apparatus configured to balance and filter an image frequency of a nominal frequency of the non-symmetrical receiving signal. The apparatus includes a modified Boucherot bridge having a series or parallel oscillating circuit that replaces inductive or capacitive components of a conventional Boucherot bridge, such that the modified Boucherot bridge is in the harmonized state with the image frequency to be faded out and has a predetermined impedance with the nominal frequency on its symmetrical output terminals. The nominal frequency has a predetermined impedance on its symmetrical output terminals. The nominal frequency is transmitted as a signal balanced to ground to the symmetrical output terminals of the modified Boucherot bridge.
Abstract:
An arrangement for processing a non-symmetrical signal includes an apparatus configured to balance and filter an image frequency of a nominal frequency of the non-symmetrical receiving signal. The apparatus includes a modified Boucherot bridge having a series or parallel oscillating circuit that replaces inductive or capacitive components of a conventional Boucherot bridge, such that the modified Boucherot bridge is in the harmonized state with the image frequency to be faded out and has a predetermined impedance with the nominal frequency on its symmetrical output terminals. The nominal frequency has a predetermined impedance on its symmetrical output terminals. The nominal frequency is transmitted as a signal balanced to ground to the symmetrical output terminals of the modified Boucherot bridge.
Abstract:
An arrangement for transmitting magnetic resonance signals, with a transmission link that connects a local coil with a receiver, has a first channel of the local coil with a first single antenna to acquire a first magnetic resonance signal, as well as a first mixer connected with the first single antenna. The first mixer forms an intermediate-frequency first signal from the supplied first magnetic resonance signal. A second channel of the local coil has a second single antenna to acquire a second magnetic resonance signal, as well as a second mixer connected with the second single antenna. The second mixer forms an intermediate-frequency second signal from the supplied second magnetic resonance signal. The local coil has a device for signal combination that, by frequency multiplexing, that combines the intermediate-frequency first signal of the first channel and the intermediate-frequency second signal of the second channel so that it arrives at the receiver via the transmission path. The receiver has an A/D converter at which one of the transmitted intermediate-frequency signals of an associated channel arrives in order to be sampled with a sampling frequency for digitization. For frequency conversion, a first local oscillator frequency is connected at the first mixer and a second local oscillator frequency is connected at the second mixer. the first and second local oscillator frequencies are selected such that intermediate-frequencies formed by the frequency conversion are mirror-symmetrical relative to the sampling frequency of the A/D converter.