Methods and devices for testing the operation of counters used in phase-locked loops
    1.
    发明授权
    Methods and devices for testing the operation of counters used in phase-locked loops 有权
    用于测试锁相环中计数器运行的方法和装置

    公开(公告)号:US06356126B1

    公开(公告)日:2002-03-12

    申请号:US09612980

    申请日:2000-07-10

    IPC分类号: H03L700

    摘要: Intermittent miscounts generated by counters used in a phase-locked loop (“PLL”) are precisely measured by detecting changes to a predetermined waveform, such as a sawtooth waveform. The miscounts are detected using an open loop, not closed loop, set-up which comprises two separate signal generators feeding two separate frequencies into MAIN and REF counters of a PLL. Offsetting the frequencies slightly and integrating an output generates the predetermined waveform. Thereafter, miscounts can be detected by comparing waveforms corresponding to miscounts to theoretically predicted, predetermined waveforms.

    摘要翻译: 通过检测诸如锯齿波形之类的预定波形的变化来精确地测量由锁相环(“PLL”)中使用的计数器产生的间歇性错误计数。 使用开环(而不是闭环)来检测错误计数,该设置包括将两个分离的信号发生器馈送到PLL的MAIN和REF计数器中的两个单独的信号发生器。 略微偏移频率并积分输出产生预定波形。 此后,可以通过将对应于错误计数的波形与理论预测的预定波形进行比较来检测错误计数。

    Pre-distortion tuning for analog lasers
    2.
    发明授权
    Pre-distortion tuning for analog lasers 失效
    模拟激光器的预失真调谐

    公开(公告)号:US06246965B1

    公开(公告)日:2001-06-12

    申请号:US09164724

    申请日:1998-10-01

    IPC分类号: C01D2100

    摘要: In a test configuration for a pre-distortion board configured with an analog laser, a test operator adjusts the settings for one or more components (e.g., potentiometers) on the pre-distortion board, e.g., to optimize the linearity of the analog laser, relying on information contained in a graphical display presented on a computer monitor. In one embodiment, a signal generator generates electrical signals, the pre-distortion board distorts the electrical signals, the analog laser converts the distorted electrical signals into optical signals, an optical receiver converts the optical signals back into electrical signals, a band-pass filter filters the converted electrical signals, an RF spectrum analyzer generates amplitude vs. frequency data from the filtered electrical signals, and a computer generates the graphical display from the amplitude vs. frequency data, wherein the graphical display has a bar graph that graphically and textually indicates the current distortion level of the analog laser relative to a distortion requirement level and an extreme distortion level for the current test.

    摘要翻译: 在配置有模拟激光器的预失真板的测试配置中,测试操作员调整预失真板上的一个或多个组件(例如,电位计)的设置,例如,为了优化模拟激光器的线性度, 依赖于在计算机监视器上呈现的图形显示中所包含的信息。 在一个实施例中,信号发生器产生电信号,预失真板扭曲电信号,模拟激光器将失真的电信号转换为光信号,光接收器将光信号转换回电信号,带通滤波器 对经转换的电信号进行滤波,RF频谱分析仪从经滤波的电信号产生幅度与频率数据,并且计算机从幅度 - 频率数据生成图形显示,其中图形显示具有图形和文本表示的条形图 模拟激光器的当前失真水平相对于当前测试的失真要求水平和极端失真水平。