Method for matching antennas in a nuclear magnetic resonance imaging
apparatus
    1.
    发明授权
    Method for matching antennas in a nuclear magnetic resonance imaging apparatus 失效
    用于匹配核磁共振成像装置中的天线的方法

    公开(公告)号:US5208537A

    公开(公告)日:1993-05-04

    申请号:US788593

    申请日:1991-11-06

    CPC分类号: G01R33/3628

    摘要: In a method for matching a transmission/reception antenna in a nuclear magnetic resonance imaging apparatus to the impedance of a high-frequency system which feeds the antenna, a directional coupler is used for acquiring respective signals corresponding to a forward voltage wave supplied to the antenna, and the associated return voltage wave. The amplitudes of the forward and return waves are calculated in a controller for all matching conditions of a transformation network, the transformation network being interconnected between the high frequency system and the antenna. When a tomogram is to be produced, the transformation network is set so that the antenna is matched as best as is possible to the high-frequency system. The same method can be used for matching an antenna which is only used for reception when producing tomograms.

    摘要翻译: 在将核磁共振成像装置中的发送接收天线与馈送天线的高频系统的阻抗进行匹配的方法中,使用定向耦合器来取得与提供给天线的正向电压波对应的各信号 ,以及相关的返回电压波。 转换网络的所有匹配条件的控制器计算正向和返回波的幅度,变换网络在高频系统和天线之间互连。 当要产生断层图像时,转换网络被设置为使得天线能够尽可能地匹配到高频系统。 可以使用相同的方法来匹配仅在生成断层图像时用于接收的天线。

    High-frequency power amplifier
    2.
    发明授权
    High-frequency power amplifier 有权
    高频功率放大器

    公开(公告)号:US6160453A

    公开(公告)日:2000-12-12

    申请号:US220111

    申请日:1998-12-23

    IPC分类号: H03F3/26 H03F3/04

    CPC分类号: H03F3/265

    摘要: A high-frequency power amplifier has a high-frequency input, a high-frequency output and at least one power transistor connected therebetween. The power transistor has a first electrode serving as a control input, a cooling terminal connected to a second electrode and a third electrode. The third electrode is connected to a high-frequency reference potential conductor and the high-frequency reference potential conductor is connected in terms of high-frequency to the second electrode. An input signal applied to the high-frequency input is coupled out as an output signal at the high-frequency output.

    摘要翻译: 高频功率放大器具有连接在其间的高频输入,高频输出和至少一个功率晶体管。 功率晶体管具有用作控制输入的第一电极,连接到第二电极和第三电极的冷却端子。 第三电极连接到高频参考电位导体,高频参考电位导体以高频率连接到第二电极。 施加到高频输入的输入信号作为高频输出端的输出信号被耦合出来。

    High-frequency receiver, particularly for a nuclear magnetic resonance apparatus
    3.
    发明授权
    High-frequency receiver, particularly for a nuclear magnetic resonance apparatus 有权
    高频接收机,特别是用于核磁共振设备

    公开(公告)号:US06297637B1

    公开(公告)日:2001-10-02

    申请号:US09221810

    申请日:1998-12-29

    IPC分类号: G01V300

    CPC分类号: G01R33/3621

    摘要: A high-frequency receiver with an analog input part has at least one analog mixer stage, this mixer stage being operable with an injection frequency, and a following digitalization stage. The digitalization stage includes an analog-to-digital converter for digitalizing a signal emitted by the analog input part with a sampling rate prescribed by a sampling frequency. A signal generator for generating the injection frequency or the sampling frequency is connected to the mixer stage and to the analog-to-digital converter, this signal generator generating the injection frequency or the sampling frequency only as a whole number multiple of a basic frequency.

    摘要翻译: 具有模拟输入部分的高频接收器具有至少一个模拟混频器级,该混频器级可以以注入频率和随后的数字化级工作。 数字化级包括用于以由采样频率规定的采样率数字化由模拟输入部分发射的信号的模拟 - 数字转换器。 用于产生喷射频率或采样频率的信号发生器连接到混频器级和模拟 - 数字转换器,该信号发生器仅产生基本频率的整数倍的注入频率或采样频率。

    Analog-to-digital converter circuit
    4.
    发明授权
    Analog-to-digital converter circuit 失效
    模数转换电路

    公开(公告)号:US06285305B1

    公开(公告)日:2001-09-04

    申请号:US09538358

    申请日:2000-03-29

    IPC分类号: H03M162

    CPC分类号: H03M1/188

    摘要: An analog-to-digital converter circuit has pre-sample and hold circuit for acquiring and temporarily storing a supplied analog input signal, and for outputting the temporarily stored input signal, at least two signal paths, which are arranged downstream relative to the pre-sample and hold circuit and which are switched in parallel with one another, the temporarily stored input signal sample from the pre-sample and hold circuit being subjected to respective fixed amplifications, which are different from one another, in said signal paths and a selection circuit arranged downstream relative to the signal paths for through-connecting only one of the signal paths, dependent on the respective signal levels, to an analog-to-digital converter that is arranged downstream relative to the selection circuit.

    摘要翻译: 模拟 - 数字转换器电路具有用于获取和临时存储所提供的模拟输入信号的预采样和保持电路,并且用于输出临时存储的输入信号至少两个信号路径, 采样和保持电路并且彼此并联切换,来自预采样和保持电路的临时存储的输入信号采样在所述信号路径中经受彼此不同的相应的固定放大和选择电路 布置在相对于信号路径的下游,用于仅将信号路径中的一个根据相应的信号电平连接到相对于选择电路布置在下游的模拟 - 数字转换器。

    High-frequency power amplifier
    5.
    发明授权
    High-frequency power amplifier 有权
    高频功率放大器

    公开(公告)号:US06281755B1

    公开(公告)日:2001-08-28

    申请号:US09221049

    申请日:1998-12-28

    IPC分类号: H03F3191

    摘要: A high-frequency power amplifier for feeding an antenna of a nuclear magnetic resonance tomography apparatus has at least one amplifier stage that can emit a maximum output power within a first frequency band. Circuitry for frequency-dependently altering the maximum output power is connected to the amplifier stage, whereby the maximum output power within a second frequency band, that is higher than the first frequency band is higher than within the first frequency band.

    摘要翻译: 用于馈送核磁共振断层摄影装置的天线的高频功率放大器具有至少一个可在第一频带内发射最大输出功率的放大器级。 用于频率依赖性地改变最大输出功率的电路连接到放大器级,由此在比第一频带高的第二频带内的最大输出功率高于第一频带内的最大输出功率。

    Analog-to-digital converter with level converter and level recognition unit and correction memory
    6.
    发明授权
    Analog-to-digital converter with level converter and level recognition unit and correction memory 有权
    具有电平转换器和电平识别单元和校正存储器的模数转换器

    公开(公告)号:US06195031B1

    公开(公告)日:2001-02-27

    申请号:US09221048

    申请日:1998-12-28

    IPC分类号: H03M136

    CPC分类号: H03M1/188

    摘要: An analog-to-digital converter circuit for digitalizing a high-frequency signal with large dynamics has a first analog-to-digital converter and a second analog-to-digital converter connected in parallel, a level converter connected to one of the two analog-to-digital converters, a level recognition element for determining a level range in which the high-frequency signal lies and for generating a control signal dependent on the level range, and a correction memory that is connected to the level recognition element, the correction memory having address inputs connected to outputs of the analog-to-digital converters. The control signal is used as a selection criterion which identifies which analog-to-digital converter address data are taken from for producing a digital output signal, the digital output signal being linearized according to a characteristic of the selected analog-to-digital converter in order to correct for distortion arising in the selected converter. The overall analog-to-digital converter circuit thus has an overall linear characteristic, even as the input signal varies between low and high amplitudes.

    摘要翻译: 用于以大动态数字化高频信号的模数转换器电路具有并联连接的第一模数转换器和第二模数转换器,电平转换器连接到两个模拟 数字转换器,用于确定高频信号所在的电平范围并用于产生取决于电平范围的控制信号的电平识别元件,以及连接到电平识别元件的校正存储器,校正 具有连接到模数转换器的输出的地址输入的存储器。 该控制信号用作选择标准,其标识从哪个模拟 - 数字转换器地址数据获取用于产生数字输出信号,数字输出信号根据所选择的模数转换器的特性被线性化 以纠正所选转换器中出现的失真。 因此,总体模数转换器电路具有总体线性特性,即使输入信号在低和高幅度之间变化。

    AMPLIFIER DEVICE WITH ADJUSTABLE SUPPLY VOLTAGE
    7.
    发明申请
    AMPLIFIER DEVICE WITH ADJUSTABLE SUPPLY VOLTAGE 失效
    具有可调电源电压的放大器器件

    公开(公告)号:US20080079488A1

    公开(公告)日:2008-04-03

    申请号:US11862303

    申请日:2007-09-27

    IPC分类号: H03G3/00 H04B1/04

    摘要: A radio-frequency power amplifier is supplied by a voltage supply device. The voltage supply device has a voltage divider chain that is connected at the input side with a base potential and a ground voltage. The voltage divider chain has a number of Zener diodes connected in series, with which at least one capacitor is connected in parallel. Intermediate voltages that lie between the ground voltage and the base potential can be tapped at respective node points between each two immediately adjacent Zener diodes. A first supply input of the radio-frequency power amplifier is connected with the ground voltage. The voltage divider chain is connected with the radio-frequency power amplifier via a switching device. The switching device has a number of switching elements connected in parallel with one another, these switching elements being connected at the output side with a second supply input of the radio-frequency power amplifier. The base potential or one of the intermediate voltages is present at the input side of each switching element. The switching elements can be individually controlled by a control device, such that the second supply input can be selectively connected with the base potential and each of the intermediate voltages via the switching device.

    摘要翻译: 射频功率放大器由电压供给装置提供。 电压供给装置具有在输入侧连接有基极电位和接地电压的分压器链。 分压器链具有串联连接的多个齐纳二极管,至少一个电容器并联连接。 位于接地电压和基极电位之间的中间电压可以在每个两个紧邻的齐纳二极管之间的相应节点处被抽头。 射频功率放大器的第一个电源输入端与接地电压相连。 分压器链通过开关装置与射频功率放大器相连。 开关装置具有彼此并联连接的多个开关元件,这些开关元件在输出侧连接有射频功率放大器的第二电源输入端。 基极电位或中间电压之一存在于每个开关元件的输入侧。 开关元件可以由控制装置单独控制,使得第二电源输入可以经由开关装置选择性地连接到基极电位和每个中间电压。

    Amplifier device with adjustable supply voltage
    8.
    发明授权
    Amplifier device with adjustable supply voltage 失效
    具有可调电源电压的放大器

    公开(公告)号:US07532067B2

    公开(公告)日:2009-05-12

    申请号:US11862303

    申请日:2007-09-27

    IPC分类号: H03G3/00

    摘要: A radio-frequency power amplifier is supplied by a voltage supply device. The voltage supply device has a voltage divider chain that is connected at the input side with a base potential and a ground voltage. The voltage divider chain has a number of Zener diodes connected in series, with which at least one capacitor is connected in parallel. Intermediate voltages that lie between the ground voltage and the base potential can be tapped at respective node points between each two immediately adjacent Zener diodes. A first supply input of the radio-frequency power amplifier is connected with the ground voltage. The voltage divider chain is connected with the radio-frequency power amplifier via a switching device. The switching device has a number of switching elements connected in parallel with one another, these switching elements being connected at the output side with a second supply input of the radio-frequency power amplifier. The base potential or one of the intermediate voltages is present at the input side of each switching element. The switching elements can be individually controlled by a control device, such that the second supply input can be selectively connected with the base potential and each of the intermediate voltages via the switching device.

    摘要翻译: 射频功率放大器由电压供给装置提供。 电压供给装置具有在输入侧连接有基极电位和接地电压的分压器链。 分压器链具有串联连接的多个齐纳二极管,至少一个电容器并联连接。 位于接地电压和基极电位之间的中间电压可以在每个两个紧邻的齐纳二极管之间的相应节点处被抽头。 射频功率放大器的第一个电源输入端与接地电压相连。 分压器链通过开关装置与射频功率放大器相连。 开关装置具有彼此并联连接的多个开关元件,这些开关元件在输出侧连接有射频功率放大器的第二电源输入端。 基极电位或中间电压之一存在于每个开关元件的输入侧。 开关元件可以由控制装置单独控制,使得第二电源输入可以经由开关装置选择性地连接到基极电位和每个中间电压。

    AMPLIFIER DEVICE
    10.
    发明申请
    AMPLIFIER DEVICE 有权
    放大器器件

    公开(公告)号:US20080143438A1

    公开(公告)日:2008-06-19

    申请号:US11953111

    申请日:2007-12-10

    IPC分类号: H03F3/00

    CPC分类号: H03F1/0244

    摘要: An amplifier device has an amplifier circuit, an energy supply device, a switching matrix and a control device. A radio-frequency, low-energy signal pulse can be amplified into a high-energy power pulse by the amplifier circuit. The amplifier circuit is supplied with electrical energy by the energy supply device. The energy supply device has a number of electrical energy sources that are separated in terms of potential relative to one another in a state in which they are not connected to the amplifier circuit. The electrical energy sources can be selectively connected to the amplifier circuit by the switching matrix. The switching state of the switching matrix can be dynamically set for this purpose by the control device.

    摘要翻译: 放大器装置具有放大器电路,能量供给装置,开关矩阵和控制装置。 射频,低能量信号脉冲可以由放大器电路放大为高能量功率脉冲。 放大器电路由能量供给装置供电。 能量供给装置具有多个电能源,它们在未连接到放大器电路的状态下相对于彼此分离。 电能可以通过开关矩阵选择性地连接到放大器电路。 开关矩阵的切换状态可以通过控制装置动态设定。