利索-全球专利检索

  1. 登录
  2. 注册

搜索结果

107 条记录 (耗时 0.01 秒)

    Multibit delta-sigma modulator with variable-level quantizer
    56.
    发明申请
    Multibit delta-sigma modulator with variable-level quantizer 有权

    公开(公告)号：US20050093727A1

    公开(公告)日：2005-05-05

    申请号：US10699466

    申请日：2003-10-31

    申请人： Brian Trotter ,  Bruce Duewer

    发明人： Brian Trotter ,  Bruce Duewer

    IPC分类号： H03M7/38 ,  H03C3/30

    CPC分类号： H03M7/3011 ,  H03M7/3026 ,  H03M7/3037

    摘要： A method of operating a delta-sigma modulator by providing a variable-level quantizer, which selectively enables an additional quantizer level(s) during a ramp up sequence of the modulator. The additional quantizer level(s) is/are disabled during normal operation. The quantizer truncates a summer output and selectively enables the additional quantizer levels by clipping the truncated sum within a first range of quantizer levels during the ramp up sequence and within a second range of quantizer levels during normal operation in which there are more quantizer levels in the first range than in the second range. The quantizer preferably enables at least two additional quantizer levels at a low end of the quantizer range. For example, the range of quantizer levels for normal operation of the modulator can be from −6 to +6, while the range of quantizer levels for ramp up operation of the modulator can be from −8 to +7.

    Microwave tube amplifier stage with wide band and low dispersivity in frequency
    57.
    发明授权
    Microwave tube amplifier stage with wide band and low dispersivity in frequency 失效
    具有宽带和低频率的微波管放大器级

    公开(公告)号：US5103187A

    公开(公告)日：1992-04-07

    申请号：US678240

    申请日：1991-04-01

    申请人： Alain Durand ,  Olivier Rabot

    发明人： Alain Durand ,  Olivier Rabot

    IPC分类号： H03F3/58 ,  H03C3/30 ,  H03F3/54

    CPC分类号： H03C3/30 ,  H03F3/54

    摘要： This amplifier stage comprises a microwave tube wherein an electron beam (3) is made to interact with a microwave having a frequency variable within a given useful range, the velocity of the electrons of the beam being determined by a cathode voltage (V.sub.k) applied to the tube and the microwave being propagated in said delay structure (4) that imposes a phase velocity close to the velocity of the electron beam on said microwave. The cathode voltage is a variable voltage, regulated as a function of said frequency, said voltage varying with the frequency to modify the velocity of the electrons of the beam in such a way that, for every frequency of said useful range of frequencies, the corresponding velocity of these electrons remains essentially, but not precisely, identical to the phase velocity of the microwave. Thus, the dispersivity in frequency of the delay structure is compensated for, and the output power delivered by the tube is thus kept essentially constant.

    摘要翻译： 该放大器级包括微波管，其中使电子束（3）与具有在给定有用范围内的频率可变的微波相互作用，所述光束的电子速度由施加到 管和微波在所述延迟结构（4）中传播，其施加接近于所述微波上的电子束的速度的相位速度。 阴极电压是作为所述频率的函数调节的可变电压，所述电压以频率变化以改变波束的电子的速度，使得对于所述有用频率范围的每个频率，相应的 这些电子的速度基本上保持不变，但并不精确地保持与微波的相位速度相同。 因此，对延迟结构的频率分散度进行补偿，并且由管输送的输出功率因此保持基本恒定。