公开(公告)号：US5319266A

公开(公告)日：1994-06-07

申请号：US21436

申请日：1993-02-24

Applicant: Ching Chu ,  John Haywood

Inventor： Ching Chu ,  John Haywood

IPC: G01M11/00 ,  H04B10/07 ,  B11C27/02

CPC classification number: G01M11/3154 ,  H04B10/07

Abstract: A switched boxcar integrating circuit suitable for use with high speed data acquisition systems such as an Optical Domain Reflectometer. The boxcar integrator comprises a differential pre-amplifier stage, a sampling switch, and an integrator. The sampling switch couples the output of the pre-amplifier to the input of the integrator. The integrator includes non-inverting and inverting stages for producing a differential integrated signal. The switch samples the output of the pre-amplifier. The samples are integrated by the integrator once a sufficient number have been acquired. The sampling switch includes a switch controller to synchronize the operation of the switch with the received signals. The integrator also includes an offset compensator and a reset switch which are coupled to the integrator. The offset compensator and reset switch set the integrator to zero and also correct any offset error. A feature of the boxcar integrator according to the present invention is the variable integrator aperture which allows the response of the receiver stage in an OTDR to be matched to the characteristics of the transmit stage.

Abstract translation: 一种适用于高速数据采集系统（如光学域反射计）的开关盒式积分电路。 盒式积分器包括差分前置放大器级，采样开关和积分器。 采样开关将前置放大器的输出端耦合到积分器的输入端。 积分器包括用于产生差分积分信号的同相和反相级。 开关对前置放大器的输出进行采样。 一旦获得足够的数量，样品就被积分器集成。 采样开关包括开关控制器，以将开关的操作与所接收的信号同步。 积分器还包括耦合到积分器的偏移补偿器和复位开关。 偏移补偿器和复位开关将积分器设置为零，并且还校正任何偏移误差。 根据本发明的箱式积分器的特征是可变积分器孔径，其允许OTDR中的接收机级的响应与发射级的特性匹配。

公开(公告)号：US5422643A

公开(公告)日：1995-06-06

申请号：US21435

申请日：1993-02-24

Applicant: Ching Chu ,  Steven Prowse ,  John Haywood

Inventor： Ching Chu ,  Steven Prowse ,  John Haywood

IPC: G01M11/00 ,  H03M1/18

CPC classification number: G01M11/3145 ,  H03M1/187

Abstract: A digitizer suitable for digitizing input signals having a high dynamic range. The digitizer is microprocessor controlled and comprises an input stage, a multi-channel attenuator or amplifier bank, a multiplexer and a analog-to-digital (A/D) converter. The function of the multi-channel bank is to move the input signal within the range of the A/D converter. The input signal to be digitized is fed through the input stage to each of the channels in the attenuator bank. The signal is scaled by each respective channel in the attenuator bank. The multiplexer is used to switch the scaled signal which is within the range of the A/D converter for digitizing. The digitized sample is then corrected according to the attenuation or gain factor of the scaled channel. The digitizer includes a comparator bank which is used to determine the channel with the widest signal range within the range of the A/D converter. The digitizer also includes a channel calibrator for calibrating the actual gain or attenuation of each channel. In another aspect, the digitizer can be implemented using an optical front-end comprising an optical beam splitter, optical attenuators and amplifier banks. The optical front-end provides improved noise immunity and faster speed of operation.

Abstract translation: 适用于数字化具有高动态范围的输入信号的数字转换器。 数字转换器由微处理器控制，包括输入级，多通道衰减器或放大器组，多路复用器和模拟（A / D）转换器。 多通道组的功能是在A / D转换器的范围内移动输入信号。 要被数字化的输入信号通过输入级馈送到衰减器组中的每个通道。 信号由衰减器组中的每个相应通道进行缩放。 多路复用器用于切换在A / D转换器范围内的缩放信号进行数字化。 然后根据缩放的通道的衰减或增益因子校正数字化采样。 数字转换器包括一个比较器组，用于确定A / D转换器范围内最宽信号范围的通道。 数字转换器还包括用于校准每个通道的实际增益或衰减的通道校准器。 在另一方面，可以使用包括光分束器，光衰减器和放大器组的光学前端来实现数字化仪。 光学前端提供更好的抗噪声能力和更快的操作速度。

公开(公告)号：US5485264A

公开(公告)日：1996-01-16

申请号：US166546

申请日：1993-12-14

Applicant: Ching Chu ,  Mike VanderWindt

Inventor： Ching Chu ,  Mike VanderWindt

IPC: G01M11/00 ,  G01N21/88

CPC classification number: G01M11/3145

Abstract: An OTDR stores data samples in a predetermined sequence in a memory. Data is read from and written to the memory in the predetermined sequence by application of successive control signals. The stored data is read, added to a correlated sample of a new signal and the result stored to maintain the predetermined sequence of samples. Successive tests thus accumulate samples in sequence to provide an indication of the variation of the signal as the light pulse passes along the fiber under tests.

Abstract translation: OTDR以预定的顺序将数据样本存储在存储器中。 通过应用连续的控制信号，以预定的顺序读取和写入数据。 读取存储的数据，将其添加到新信号的相关样本，并存储结果以维持预定的样本序列。 因此，连续测试按顺序累积样本，以提供当光脉冲沿着被测光纤通过时的信号变化的指示。

公开(公告)号：US5465143A

公开(公告)日：1995-11-07

申请号：US186966

申请日：1994-01-27

Applicant: Ching Chu ,  David Liao ,  Kai D. Feng

Inventor： Ching Chu ,  David Liao ,  Kai D. Feng

IPC: G01M11/00 ,  G01N21/88

CPC classification number: G01M11/3145

Abstract: An OTDR to examine light reflected from an optic fibre has an amplification stage that operates in either a high gain or low gain mode. To avoid saturation of the amplifier in the high gain mode, the trace is examined to identify the location of spikes and a switch is controlled to connect the amplifier to the signal after the occurrence of the spike.

Abstract translation: 检查从光纤反射的光的OTDR具有以高增益或低增益模式工作的放大级。 为了避免放大器在高增益模式下饱和，检查迹线以识别尖峰的位置，并且控制开关以在发生尖峰之后将放大器连接到信号。

公开(公告)号：US5442434A

公开(公告)日：1995-08-15

申请号：US143037

申请日：1993-10-29

Applicant: David D. Liao ,  Andrew E. Forber

Inventor： David D. Liao ,  Andrew E. Forber

IPC: G01M11/00 ,  G01N21/88

CPC classification number: G01M11/3145

Abstract: A method for identifying optical features along the length of a fiber optic cable in response to injecting a pulse of light into the fiber optic cable and collecting data corresponding to signals which are reflected, the method comprising the steps of: identifying potential optical features in the data according to a first set of parameters; constructing a pattern for selecting optical features from said potential optical features; fitting said pattern to said optical features; determining a position along the cable for each of said optical features; and computing a reflectance/loss level for each of said optical features.

Abstract translation: 一种用于响应于将光脉冲注入光纤电缆并且收集对应于被反射的信号的数据而识别沿光纤电缆的长度的光学特征的方法，所述方法包括以下步骤：识别所述光纤特征 数据根据第一组参数; 构建用于从所述潜在光学特征中选择光学特征的图案; 将所述图案拟合成所述光学特征; 为每个所述光学特征确定沿着所述电缆的位置; 以及计算每个所述光学特征的反射/损耗水平。