Abstract: A system and method for compensating for the time delay between the in-phase I and the quadrature Q paths of a digitally modulated transmitter incorporating an analog quadrature modulator is disclosed. The time delay between the in-phase I and the quadrature Q paths is computed and used to calibrate a set of interpolation filters in the forward path that compensate for this delay, reducing the frequency dependent degradation in performance of the analog quadrature modulator. The disclosed system and method provides improved compensation of gain, phase and DC offsets in the analog quadrature modulator over a broader bandwidth. Fractional delay interpolation filters may be used to estimate the delay between the in-phase and quadrature paths. This eliminates the need for a factory calibration procedure, speeding up manufacture and reducing costs.

Abstract: A system and method for signal peak reduction in a multiple carrier communication system where the individual carriers are produced from input symbols that are filtered to reduce individual carrier bandwidths, offset in frequency, and combined into an output signal. A multiple carrier peak reduction unit is provided which modifies the input carrier symbols so that the combined output signal does not exceed a predetermined peak limit value. The multiple carrier peak reduction unit includes filter predictors that predict the effect of each channel filter on that carriers input symbols by using filter coefficient values corresponding to the impulse response function of each filter. The filter predictor outputs are then phase shifted, in correspondence to frequency offsets provided for in multiple carrier signal generation, and combined to produce a prediction of the combined signal output which is then processed to determine the corrections required to the individual channel symbol inputs.

Abstract: A suspended p-GaN membrane is formed using photochemical etching which membrane can then be used in a variety of MEMS devices. In the illustrated embodiment a pump is comprised of the p-GaN membrane suspended between two opposing, parallel n-GaN support pillars, which are anchored to a rigid substrate below the pillars. The p-GaN membrane bows upward between the pillars in order to relieve stress built up during the epitaxial growth of membrane. This bowing substantially increases the volume of the enclosed micro-channel defined between membrane and substrate below. The ends of membrane are finished off by a gradual transition to the flat underlying n-GaN layer in which fluidic channels may also be defined to provide inlet and outlet channels to microchannel. A traveling wave or sequential voltage applied to the electrodes causes the membrane to deform and provide a peristaltic pumping action in the microchannel.

Abstract: A kiosk includes multiple poles with a plurality of independently rotatable components disposed on each pole. Each component comprises a hollow supporting body made rotatable by way of bushings disposed on the top and bottom of the body and bearings disposed adjacent to each bushing. The component further includes a pair of slat boards removably coupled to the supporting body. Even though each slat board may have a different configuration of protrusions extending from the front surface for holding goods, clips on the back surface of each board are similarly configured to enable any board to be removably coupled to a supporting body. Related methods are also disclosed.

Abstract: A method for supporting a wall-like structure by forming a serpentine shaped slot on a substantially planar surface. The serpentine slot includes an area of central clearance such that a wall-like structure having a width narrower than the width of the serpentine slot can be inserted into the area of central clearance and be supported by the inner sides of the serpentine slot.

Abstract: An RF power amplifier with amplifier stage failure detection comprises an amplifier input for receiving an RF signal to be amplified, an amplifier output for outputting an amplified RF signal, a plurality of separate amplifier stages coupled between the amplifier input and amplifier output so as to cumulatively provide a desired amplifier gain to the input RF signal, and means for detecting amplifier stage failure by providing a pilot tone to the amplifier stages, duty cycling the amplifier stages based on a separate timing for each stage and detecting the pilot tone output from the stages based on the timing.

Abstract: The invention is a fast-scanning ODT system that uses phase information derived from a Hilbert transformation to increase the sensitivity of flow velocity measurements while maintaining high spatial resolution. The significant increases in scanning speed and velocity sensitivity realized by the invention make it possible to image in vivo blood flow in human skin. The method of the invention overcomes the inherent limitations of the prior art ODT by using a phase change between sequential line scans for velocity image reconstruction. The ODT signal phase or phase shifts at each pixel can be determined from the complex function, {tilde over (&Ggr;)}ODT(t), which is determined through analytic continuation of the measured interference fringes function, &Ggr;ODT(t), by use of a Hilbert transformation, by electronic phase demodulation, by optical means, or a fast Fourier transformation. The phase change in each pixel between axial-line scans is then used to calculate the Doppler frequency shift.

Abstract: An unified constant-frequency integration (UCI) control method based on one-cycle control employs an integrator with reset as its core component along with a few logic and linear components to control the pulse width of a three-phase recitifier, active power filter, or grid-connected inverter so that the all three phase current draw from or the current output to the utility line is sinusoidal. No multipliers and reference calculation circuitry are needed for controlling active power filters. The UCI control employs constant switching frequency and operates in continuous conduction mode (CCM). If in some cases a DSP is desired for some other purposes, the Unified Constant-frequency Control function can be realized by a low cost DSP with a high reliability, because no high speed calcutation, high speed A/D converter, and mutipliers are required.

Abstract: A method for manufacturing a discrete power rectifier device having a VLSI multi-cell design employs a two spacer approach to defining a P/N junction profile having good breakdown voltage characteristics. The method provides highly repeatable device characteristics at reduced cost. The active channel regions of the device are also defined using the same two spacers. The method is a self-aligned process and channel dimensions and doping characteristics may be precisely controlled despite inevitable process variations in spacer formation. Only two masking steps are required, and additional spacers for defining the body region profile can be avoided, reducing processing costs.

Abstract: The emission properties of light-emitting diodes are enhanced by coupling to surface plasmons. The semiconductor emitter layer of the light-emitting diode is thinner than &lgr;/2 and is sandwiched between two metal films. A periodic pattern is defined in the top semitransparent metal layer by lithography with the result that it efficiently couples out the light emitted from the semiconductor and simultaneously enhances the spontaneous emission rate. Extraction efficiencies of up to 35% and Purcell factors of up to 4.5 are obtainable. Photoluminescence intensities of up to 46 times higher in fabricated structures compared to unprocessed wafers are obtained. The increased light emission is due to an increase in the efficiency and an increase in the pumping intensity resulting from trapping of pump photons within the microcavity.

Abstract: A cutter carriage for moving a rotary cutter between a front side of the back roller and a back side of the back roller. The preferred system has a pair of guide rods located on the left and right side plates of the sheeting head. The rotary cutter is held at either end by pivot arms. Each arm, in turn is attached to a carriage side piece that slidingly engages one of the guide rods. The two side pieces are joined into a single cutter carriage by an elongate member parallel to the rotary cutter. Each carriage is equipped with a cutter engagement system that moves the pivot arms and attached rotary cutter into an operational position in relation to the sheeting head. When the rotary cutter is serviced, the engagement system is released allowing the pivot arm to move the rotary cutter away from the sheeting head roller, and the cutter carriage is slid along the guide rods making the rotary cutter readily accessible from the rear side of the sheeting head.

Abstract: Microdermabrasion and suction massage apparatus are included in a single unit and alternatively connectable through a mode switch to a source of vacuum. The microdermabrasion section of the unit includes a crystal pick up station operating with a venturi effect to draw crystals through a hole into an air stream. The size of the hole is variable to control crystal density. A bleed valve is provided to control crystal velocity without controlling crystal density, while a bypass valve is provided to control crystal density without controlling crystal velocity. In an associated method, a microdermabrasion procedure is performed on the skin of a patient at an operative site. The mode switch is operated to activate the suction massage apparatus within the unit. This step is followed by performing a suction massage procedure at the operative site in order to promote healing of the abraded skin. The unit can be back-flushed by connecting various portions of the unit to a pressurized output of the source of vacuum.

Abstract: The Mamikon spinner is a continuous 3 twist, single surface, having threefold symmetry and dynamic properties. It spins with a slight flow of air in the direction of the axes, and when rotated about the axis of symmetry, it acts as a blade, propeller or fan, providing for a multiplicity of utilitarian, educational, entertainment and ornamental uses.

Abstract: A low cost radio frequency interference filter assembly comprises a multiple layer structure including a middle trace layer disposed between an upper ground layer and lower ground layer. Non-conductive insulation layers are disposed between the middle trace layer and the upper and lower ground layers. The upper layer includes input contacts, signal contacts, and capacitors which are coupled to the signal contacts and an upper grounded substrate. The middle trace layer includes a grounded substrate and trace lines which are coupled to the signal contacts of the upper layer by signal vias. The lower layer includes a grounded substrate. Ground vias are formed through the insulation layers to couple the middle grounded substrate to the upper and lower grounded substrates. The filter assembly may be formed as an integral projection of a printed circuit board assembly.

Abstract: A broad class of devices, both active and passive, such as waveguides, microcavities, filters, resonators, lasers, switches, modulators, etc. can be fabricated using the disclosed method. The method is one in which nanocavities in semiconductor membranes can be fabricated, which method is an advantage regardless of the type of device which is ultimately being fabricated therefrom. The method of the invention is illustrated in the case of a photonic crystals waveguide as being made in a silicon-on-insulator (SOI) material. However, the method is not limited to this type of material and can be used in other equivalent material structures such as AlGaAs, InGaAsP, or the like. The semiconductor membranes which are fabricated incorporate two dimensional photonic crystals for confinement of light in the lateral or in-plane direction and total internal reflection for the confinement in vertical direction.

Abstract: Optical microcavities based on two dimensional arrays of holes defined in photonic crystals are optimized for maximum Q factors and minimum mode volume. They can also be used for strong coupling between the cavity field and an atom trapped within a defect of the photonic crystals, or for tunable filters if the holes are filled with electro-optical polymers. In one embodiment the Q factor of a cavity is increased by elongation of a plurality of holes in at least one row in a predetermined direction. Modal structures of microcavities, as well as quality factors, mode volumes, symmetry properties and radiation patterns of localized defect modes as a function of the slab thickness and parameters of photonic crystal and defects are illustrated.