公开(公告)号：US07522784B2

公开(公告)日：2009-04-21

申请号：US11673097

申请日：2007-02-09

申请人： Karl Kissa ,  David Glassner

发明人： Karl Kissa ,  David Glassner

IPC分类号： G02F1/66 ,  G02B6/26

CPC分类号： G02B6/122 ,  E21B11/005 ,  G02B2006/1204 ,  G02F1/3132 ,  G02F2201/14 ,  G02F2203/48

摘要： The invention relates to an electro-optic directional coupler suitable for use as a variable optical attenuator at reduced voltages compared to those known in the prior art. The present invention has found that by careful selection of an asymmetric directional coupler geometry, the transfer function of the device can be shifted so that it has an operating point between maximum and minimum transmission. Signal electrodes driven in push pull configuration advantageously use this operating point to achieve significant reduction in operating voltages for switching to maximum or minimum transmission. Asymmetry is created in the directional coupler by forming the waveguides to have different propagation constants by a difference in waveguide width, depth, index of refraction or index profile. Asymmetry can alternatively be created by causing mechanical stress in the waveguides through the placement, number, or dimensions of the electrodes, or through asymmetric dielectric structures between the waveguides and the electrodes.

摘要翻译： 本发明涉及一种电光定向耦合器，其适用于与现有技术中已知的相比在降低的电压下用作可变光衰减器。 本发明已经发现，通过仔细选择非对称定向耦合器几何形状，可以移位器件的传递函数，使其具有最大和最小传输之间的工作点。 以推挽配置驱动的信号电极有利地使用该工作点来实现用于切换到最大或最小传输的工作电压的显着降低。 通过波导宽度，深度，折射率或折射率分布的差异，通过形成波导具有不同的传播常数，在定向耦合器中产生不对称性。 另外可以通过使波导中的机械应力穿过电极的布置，数量或尺寸，或通过波导和电极之间的不对称介质结构来产生不对称性。

公开(公告)号：US5639971A

公开(公告)日：1997-06-17

申请号：US720863

申请日：1996-10-04

申请人： Alvin E. Brown

发明人： Alvin E. Brown

IPC分类号： G01F1/66 ,  G02F1/66

CPC分类号： G01F1/667

摘要： A method of detecting a signal (50) in an ultrasonic flow meter sets a first threshold (52) and a second threshold (54) at a predetermined level above the first threshold (52). An ultrasonic signal (50) having a plurality of cycles is then received. Next it is determined when the ultrasonic signal (50) exceeds the first threshold (52). This time is marked a first threshold time. Then it is determined when the ultrasonic signal exceeds the second threshold (54). This time is marked a second threshold time. A time difference between the first threshold time and the second threshold time (56) is determined. When the time difference (56) exceeds a delta time, increasing the first threshold (52) a delta level.

摘要翻译： 检测超声波流量计中的信号（50）的方法将第一阈值（52）和第二阈值（54）设置在高于第一阈值（52）的预定电平。 然后接收具有多个周期的超声波信号（50）。 接下来，确定何时超声信号（50）超过第一阈值（52）。 此时间标记为第一个阈值时间。 然后确定何时超声信号超过第二阈值（54）。 此时间标记为第二个阈值时间。 确定第一阈值时间和第二阈值时间（56）之间的时间差。 当时差（56）超过增量时间时，增加第一阈值（52）增量级。