公开(公告)号：US20030215170A1

公开(公告)日：2003-11-20

申请号：US10389697

申请日：2003-03-12

Applicant: Telecommunications Research Laboratories

Inventor： Sean V. Hum ,  Robert J. Davies ,  Michal Okoniewski

IPC: G02F001/035

CPC classification number: G02F1/0356 ,  G02F2201/127

Abstract: An electro-optic modulator structure for particular use in narrowband optical subcarrier systems. A traveling wave is established across the active region of the device, instead of a standing wave. This is accomplished through the use of a directional resonator structure that prevents reverse-traveling waves from being established within the resonator. Hence, the electric field is applied to the traveling optical wave in a similar fashion to a traveling-wave modulator, except that the traveling wave has a much greater amplitude due to the build-up of energy inside the resonator. Since the modulator is operated in a traveling-wave fashion, it can be tuned to operate at any frequency using tuning elements, regardless of the length of the active region. Furthermore, the microwave and optical signals can be velocity-matched to mitigate optical transit time effects that are normally associated with a resonant modulator utilizing a standing-wave electrode structure.

Abstract translation: 一种特别用于窄带光子载波系统的电光调制器结构。 在设备的有源区域之间建立行波，而不是驻波。 这是通过使用防止在谐振器内建立反向行波的定向谐振器结构来实现的。 因此，与行波调制器相似的方式将电场施加到行进光波，除了由于谐振器内的能量的积聚而使行波具有大得多的振幅。 由于调制器以行波方式操作，所以可以使用调谐元件将其调谐到任何频率，而与有源区的长度无关。 此外，微波和光信号可以被速度匹配以减轻通常与利用驻波电极结构的谐振调制器相关联的光通过时间效应。

公开(公告)号：US20030030479A1

公开(公告)日：2003-02-13

申请号：US10156731

申请日：2002-05-24

Applicant: Telecommunications Research Laboratories.

Inventor： Christopher D. Holdenried ,  James W. Haslett ,  John G. McRory ,  Robert J. Davies

IPC: G06G007/24

CPC classification number: G06G7/24

Abstract: A parallel-summation logarithmic amplifier is described that uses a novel topology of cascaded and parallel amplifiers to achieve extremely high bandwidth. Included in the topology is a unique delay matching scheme for logarithmic amplifiers that is amenable to fabrication in integrated circuit form. The result is flat group delay over broad frequency ranges and different power levels. The resulting log amplifier is suitable for radar applications and for use in high data rate fiber-optic networks. Also described is a unique design process that yields a set of amplifier gains that closely approximate a logarithm. Also described is the novel idea of using a parallel feedback amplifier (PFA) in piecewise-approximate logarithmic amplifiers. This innovation allows for the design of broadband amplifiers with significantly different gains and similar phase characteristics, which is extremely useful when designing high-frequency logarithmic amplifiers.

Abstract translation: 描述了并联对数放大器，其使用级联和并联放大器的新颖拓扑来实现极高带宽。 在拓扑中包括一个独特的对数放大器的延迟匹配方案，可以以集成电路形式制造。 结果是在宽频率范围和不同功率水平上的平坦组延迟。 所产生的对数放大器适用于雷达应用和用于高数据速率光纤网络。 还描述了一种独特的设计过程，其产生一组近似对数的放大器增益。 还描述了在分段近似对数放大器中使用并联反馈放大器（PFA）的新颖思想。 该创新允许宽带放大器的设计具有显着不同的增益和类似的相位特性，这在设计高频对数放大器时非常有用。