Abstract: A method of controlling an amplifier, the method comprising a sampling step of using a sampler to obtain digital samples of both an output signal of said amplifier and a reference signal, a derivation step of obtaining from said samples values of a first parameter and associated values of a second parameter, an averaging step of averaging the first parameter values over ranges of the second parameter such that, for each range, an average of the first parameter is obtained by averaging the first parameter values whose associated second parameter values lie in the range, a generation step of generating a control signal for said amplifier from said averages, a suppression step of using said samples of said reference signal to inhibit the effect upon said control signal of errors in the operation of said sampler and a control step of applying the control signal to said amplifier to direct the operation of said amplifier. The invention also relates to apparatus involved in carrying out the method.

Abstract: The input signal to a digital predistorter (14) is interpolated (28) and frequency converted (36 to 44) to condition it for predistortion. Similar conditioning can be applied to signals in a feed-forward lineariser.

Abstract: Envelope-type signals are detected for the input and output of a linearised amplifier (12). The variance of the signal obtained from the output is measured and a variable delay (24) between the detected signals is adjusted to minimise the variance. The value of the variable delay then gives the propagation delays through the linearised amplifier. Further envelope-type signal from the output and interpolation can be used to enhance the adjustment of the delay to minimise variance.

Abstract: A device and method for detecting rotational drift of mirror elements in a MEMS tilt mirror array used in an optical crossconnect. The optical crossconnect directs optical signals from an input fiber to an output fiber along an optical path by rotatably positioning mirror elements in desired positions. A monitoring device disposed outside of the optical path is used to obtain images of the MEMS array or to transmit and receive a test signal through the crossconnect for detecting the presence of mirror element drift.

Abstract: Sample acquisition apparatus for sampling first and second signals within a signal processing arrangement, said apparatus comprising a sampler for capturing sections of the waveforms of both the first and second signals, a switch for alternating correction of the sampler to a point in the arrangement where said first signal can be sampled and a point in said arrangement where said second signal can be sampled and a timer for timing the operation of the switch to cause the sampler to capture a first waveform section of said first signal and a second waveform section of said second signal, wherein said second signal is responsive to said first signal and the timing of said switch is such that said second section comprises a portion that has been generated in response to said first section.

Abstract: Sample acquisition apparatus for sampling first and second signals within a signal processing arrangement, said apparatus comprising a sampler for capturing sections of the waveforms of both the first and second signals, a switch for alternating correction of the sampler to a point in the arrangement where said first signal can be sampled and a point in said arrangement where said second signal can be sampled and a timer for timing the operation of the switch to cause the sampler to capture a first waveform section of said first signal and a second waveform section of said second signal, wherein said second signal is responsive to said first signal and the timing of said switch is such that said second section comprises a portion that has been generated in response to said first section.

Abstract: Where a DSP is used to predistort the input to a radio frequency power amplifier (RF PA) in the digital domain, then the DSP can also be used to perform a mathematical clipping operation on the input signal. This means that unwanted distortion is not introduced via the clipping process.

Abstract: The invention relates to systems and methods for improving planning, scheduling, and supply chain management. Various embodiments of the invention provide systems and methods for managing inventory of different types of items in a supply chain. One aspect of the invention focuses on a method for managing inventory of similar items in a supply chain. The method includes determining a flow path for items in a supply chain, wherein the flow path comprises at least one operation. The method also includes receiving inventory data for items at each operation; storing the inventory data; determining a demand factor for the items; and determining a cost factor for the items. The method further includes based in part on the demand factor and the cost factor, determining an exchange curve for the items; and displaying a portion of the inventory data for the items and the exchange curve.

Abstract: An optically controlled switch includes first and second electrodes, a channel extending between the electrodes, and a light source positioned to illuminate the channel. The light source produces a wavelength capable of changing the material's conductivity. The channel includes a photosensitive organic material and is configured to operate as a light controlled switch.

Abstract: An optical crossconnect constructed of micro -electromechanical systems (MEMS) tilt mirror arrays for selectively routing optical signals to optic fibers. The crossconnect includes a lens array for directing optical signals from a fiber array to the MEMS mirror array. Individual mirror elements in the mirror array reflect the optic signals to additional optic elements such as a planar mirror, a transmissive/reflective optical element or a second MEMS mirror array for routing the optical signals to output optic fibers.

Abstract: The present invention is a collapsible table that has the benefit of the interlocking legs supporting each other independently of the top, and of supporting the top itself. The present invention table includes components generally referred to as interlocking legs, but because one set extends to the floor and the other set need not extend to the floor, they are more specifically referred to as table support members and table brace members. In the present invention table, there is a pair of table support members, each table support member having a general frontal view shape of an inverted “U”. There is a substantially horizontal top portion and two substantially vertical leg portions, the top portion having two receiving slots at opposite ends from one another. These two receiving slots face or open upwardly when the table support members are upright for assembly, and these receiving slots have a predetermined height, h, and a predetermined width, w−1.

Abstract: An optical crossconnect (OXC) fabric including an array of tiltable mirrors, a reflector and a plurality of optical fibers controls the position of the mirrors to optimize the transfer of a signal between an input optical fiber and an output optical fiber by monitoring the optical signal at an optical translation unit in each of the input optical fiber and the output optical fiber. The optical translation units are operable for regenerating the optical signals transmitted through the fibers.

Abstract: An optically controlled switch includes first and second electrodes, a channel extending between the electrodes, and a light source positioned to illuminate the channel. The light source produces a wavelength capable of changing the material's conductivity. The channel includes a photosensitive organic material and is configured to operate as a light controlled switch.

Abstract: The specification describes an improved Moving Anti-Reflection Switch (MARS) device structure that largely eliminates charge build up on the movable membrane, and reduces stresses that cause curling of the membrane. The improved device uses a movable membrane made of single crystal silicon.

Abstract: An opto-isolator incorporating a MEMS device includes an optical signal source and an optical signal detector defining therebeween an optical path for communication of optical signals. A MEMS device having an actuator for controlling a moveable element is disposed between the source and detector for manipulating the optical signals. In one embodiment, the moveable element is a shutter which is operable to selectively allow optical signals to be received by the detector and prevent signals from being detected. In another embodiment, the moveable member is a MEMS tilt mirror for selectively directing optical signals to the detector.

Abstract: A package for hermetically sealing a micro-electromechanical systems (MEMS) device in a hybrid circuit comprise a firewall formed on a substrate for the MEMS device and which has a height defining a cavity of the package in which the MEMS device will be sealed. A second substrate spaced from the first substrate hermetically seals the cavity when the second substrate is flip-chip bonded to the first substrate and soldered to the first substrate with a thin film metal material placed on at least a top portion of the firewall. The resulting firewall MEMS device package can be further packaged using conventional CMOS packaging techniques. By hermetically sealing the cavity, the enclosed MEMS device is protected from deleterious conditions found in the environment of conventional CMOS packaging techniques which is often detrimental to MEMS device function.

Abstract: A micro-electro-mechanical optical device is disclosed. The micro-electro-mechanical optical device includes a micro-electro-mechanical structure coupled with an optical device. Both the micro-electro-mechanical structure and the optical device are disposed on a substrate surface. The micro-electro-mechanical structure lifts the optical device a predetermined distance above the plane of the substrate surface. Thereafter, the lifted optical device is moveable relative to the plane of the substrate surface in response to an electrostatic field generated between the optical device and the substrate.

Abstract: An electro-mechanical structure which controls the movement of an optical device coupled thereto is disclosed. Both the electro-mechanical structure and the optical device are disposed on a substrate surface. The electro-mechanical structure controls the movement of the optical device by first lifting the optical device a predetermined distance above the plane of the substrate surface. Thereafter, the lifted optical device is moveable relative to the plane of the substrate surface in response to an electrostatic field generated between the electro-mechanical structure and the substrate.

Abstract: A variable optical delay line using MEMS devices. A reflector on a micro machine linear rack is positioned and spaced from an input source and/or an output to receive and reflect input light waves toward the output. The distance between the reflector and the input and output is variable and thereby enables selective path delay compensation of the input light wave signals. Other disclosed embodiments utilize pivoting MEMS mirrors and selective adjustment of the mirror pivot angles to provide the selective path delay compensation required in a light wave system.

Abstract: The invention provides tunable optical filters which incorporate a surface-micromachined out-of-plane plate having a moveable membrane with a high reflective (HR) coated mirror. The mirror defines one side of a Fabry-Perot (FP) filter cavity and is movable in a direction along an axis of the filter cavity. The other side of the filter cavity is defined by a second HR-coated mirror. In one illustrative embodiment, a first plate is formed on a substrate, and then subsequently released from the substrate and secured in a plane orthogonal to the substrate. The first HR-coated mirror is formed as part of a movable membrane supported in an opening through the first plate. The second mirror is formed on a second plate secured in another plane orthogonal to the plane of the substrate, such that the filter cavity is defined horizontally between the first and second mirrors.