47results about How to "High modulation" patented technology

A multicolor optical image-generating device comprised of an array of grating light valves (GLVs) organized to form light-modulating pixel units for spatially modulating incident rays of light. The pixel units are comprised of three subpixel components each including a plurality of elongated, equally spaced apart reflective grating elements arranged parallel to each other with their light-reflective surfaces also parallel to each other. Each subpixel component includes means for supporting the grating elements in relation to one another, and means for moving alternate elements relative to the other elements and between a first configuration wherein the component acts to reflect incident rays of light as a plane mirror, and a second configuration wherein the component diffracts the incident rays of light as they are reflected from the grating elements. The three subpixel components of each pixel unit are designed such that when red, green and blue light sources are trained on the array, colored light diffracted by particular subpixel components operating in the second configuration will be directed through a viewing aperture, and light simply reflected from particular subpixel components operating in the first configuration will not be directed through the viewing aperture.

A method for processing a signal modulated with information symbols to account for an additive offset and slope is disclosed. First, an initial estimate of offset and slope is made and hypotheses of all possible values of a sequence of one or more information symbols are then made. For each of said hypotheses, the associated data symbol sequence is used to make an improved estimate of offset and slope and the improved estimate of offset and slope are stored against each of the hypotheses. For each hypothesis, the improved estimate of offset and slope is used in calculating an expected signal value and a mismatch between a sample of the modulated signal and the expected value is computed. The hypotheses are then sequentially extended by one symbol, the slope and offset estimates are updated and the mismatches are accumulated to form a path metric value for each extended hypothesis, and resolving between said hypotheses based on said path metric values using a Viterbi Sequential Maximum Likelihood Sequence Estimation process to produce a most likely hypothesis of said modulated information symbols substantially unimpaired by said additive slope and offset.

In an electro-optic device, a stack structure including a first silicon layer of a first conductivity type and a second silicon layer of a second conductivity type has a rib waveguide shape so as to form an optical confinement area, and a slab portion of a rib waveguide includes an area to which a metal electrode is connected. The slab portion in the area to which the metal electrode is connected is thicker than a surrounding slab portion. The area to which the metal electrode is connected is set so that a range of a distance from the rib waveguide to the area to which the metal electrode is connected is such that when the distance is changed, an effective refractive index of the rib waveguide in a zeroth-order mode does not change.

Provided is a photosensitive composition for volume hologram recording capable of forming a volume hologram recording medium that less shrinks upon curing in hologram recording (in hologram formation) and resists cracking. The photosensitive composition for volume hologram recording contains an alicyclic epoxy compound (A) represented by Formula (I); a thermal acid generator (B); a radically polymerizable compound (C); a radical polymerization initiator (D); and at least one epoxy compound (E) selected from the group consisting of compounds represented by Formula (1), epoxidized fatty acid esters, and epoxidized conjugated diene polymers.

A reception method and receiver structure that are relatively simple, that have close to optimum performance, and that use high order modulation combined with a low spreading factor are disclosed. The method receives a signal transmittal in the form of sequences of coded binary symbols comprising both predefined pilot symbols and date symbols multiplied by a spreading sequence. The method also includes a step of determining a channel estimate using received predefined pilot symbols. A system for receiving a signal transmitted on a multipath transmission channel using a spread spectrum technique and low spreading factor is also disclosed.

A wireless RF data transmission system has at least one base station transmitting control information on a control channel and high speed data on at least one data channel. At least one subscriber station receives the control information and data channels, adjusting a modulation and / or coding of reception of the data in response to the control information. Preferably, the control information is transmitted using a more robust modulation, such as QPSK, than used to transmit the data, which is preferably transmitted using either 16, 64 or 256 QAM. Additionally, timing or header information for the data may be included on the control channel.

A receiver is operable at microwave frequencies and includes a substrate and waveguide-to-microstrip transition formed on the substrate for receiving microwave radio frequency (RF) signals. Surface mounted receiver components are interconnected with microstrip formed on the substrate and receive the RF signals from the waveguide-to-microstrip transition and convert the signal to an intermediate frequency (IF) for further processing. The surface mounted receiver components include a mixer circuit that receives a local oscillator (LO) signal and RF signal to produce the IF signal. A diplexer circuit and a temperature compensated attenuator circuit received the IF signal from the mixer and attenuates the IF signal to provide high signal linearity and high order modulation.

A flow-through rotary damper assembly providing highly efficient, essentially laminar fluid flow therethrough is provided. The rotary damper assembly includes a cylindrical outer body and a cylindrical inner body that are rotatable in relation to one another. The outer body defines apertures in relation to one another to allow fluid flow without requiring fluid direction change. The inner body defines a flow passage having inlet and outlet apertures that may be aligned with the apertures of the outer body to allow fluid flow therethrough, or may be rotated out of alignment to block fluid flow. The outer body includes an aperture on one end to allow fluid flow to a third compartment. The inner body also includes an end aperture that may be aligned therewith. The damper provides selectable fluid flow between each of the compartments depending on the relative position of the cylindrical inner body member.

To provide transmission and reception diversity schemes for a powerful, flexible and less complex bandwidth-efficient space-time modulation scheme there is proposed a method of and apparatus for differential multiple-norm space-time transmit diversity from a unitary space-time modulation scheme using at least two transmit antennas. In a first step a group of transmission bits is divided into a first sub-group of transmission bits and a second sub-group of transmission bits. In a second step the first sub-group of transmission bits is mapped onto a constellation matrix of a differential unitary space-time modulation scheme. In a third step a scaling factor is determined from the second sub-group of transmission bits. In a fourth step a transmission matrix is sep up through differential encoding of the constellation matrix and a previously determined transmission matrix in combination with scaling by the scaling factor. The differential multiple-norm transmit diversity according to the present invention improves distance properties of the modulation scheme which are relevant for achievable error rates and extends higher order modulation also to the area of differential transmit diversity schemes from unitary designs.

Embodiments of methods and systems are presented for generating PHY frames with multiple Reed-Solomon encoded blocks in PLC networks. In one embodiment, a MAC layer divides a data frame from a higher level into data blocks. The MAC layer may add a MAC header and / or an error-detection code to each data block. The MAC layer then passes the data blocks to a PHY layer to be individually Reed-Solomon encoded and combined into a single PHY frame for transmission on a PLC network. In other embodiments, the MAC layer passes a single data frame to the PHY layer, which divides the MAC data frame into segments to be individually Reed-Solomon encoded. The individual Reed-Solomon encoded segments are combined into a single PHY frame for transmission on a PLC network.

The invention discloses an electronic display glass cover plate surface defect detection system and method. The novel detection system comprises a structured illumination device, a lens, an image acquisition device and a processing device. The lens is arranged between the structured illumination device and a surface to be detected so that the highest degree of modulation of imaging of the surface to be detected is obtained and the accuracy of the detection result is improved. The scheduling distribution obtained by a phase shift method is used to directly show the defect information of the surface to be detected, and the image is processed by the scheduling distribution map so that binarization defect information of the detected surface is obtained. The detection method is insensitive to the ambient light, is simple and practical, can quickly acquire the surface defect distribution of the glass cover plate, is especially suitable for the field of an electronic display screen and can be used to detect the defects of the planar mirror and the planar mirror-like object.

The present disclosure relates to a device for modulating light emitted by a laser, including an optical substrate that has an electro-optical effect, at least one optical waveguide formed near a front face of the optical substrate, a first electrode that is formed with a conductive transparent film so that a part of the optical waveguide may be covered and is used for applying an electric field to the optical waveguide, a second electrode that is paired with the first electrode and is used for applying an electric field to the optical waveguide, and a third electrode that is formed with a metal film in a position that is shifted from a position just above the optical waveguide and is electrically connected with the first electrode.

The invention discloses a high-dynamic-range grating projection three-dimensional measurement method based on full-automatic exposure, and the method comprises the steps: collecting a grating projected by a projector through a camera, wherein the exposure time is an initial value t1 at this moment; calculating a stripe modulation degree coefficient I' of the collected image; solving a modulation degree threshold value I't according to a noise level curve of the camera; calculating a group of exposure moments (N) required by the whole measurement process according to a threshold value; automatically carrying out the photographing of N groups of grating stripes according to the obtained N exposure moments; solving N phase diagrams through the N groups of stripe patterns via a conventional phase shift algorithm; dividing all pixels of an original image into N groups according to the stripe modulation degree coefficient I', wherein the impact on the phases of all pixels in the i-th group in the i-th phase diagram from noise is smaller; synthesizing N phase diagrams into a final phase diagram according to the rule, and solving the three-dimensional information with the high dynamic range of an object through combining with the calibration information.

The invention relates to a modular multilevel converter and a hybrid double-unit sub-module. The modular multilevel converter comprises six bridge arms in three phases; n sub-modules are cascaded together so as to form each bridge arm, wherein at least one sub-module is a hybrid double-unit sub-module; the hybrid double-unit sub-module includes four power modules T1, T2, T3 and T4 and two capacitors C1 and C2; the anode of T1 is connected with the anode of T4; the cathode of T2 is connected with the cathode of T3; the cathode of T1 connected with the anode of T2; the cathode of the T4 is connected with the anode of T3 through the capacitor C2; the capacitor C1 is connected between the joint point of T1 and T4 and the joint point of T2 and T3; the joint point of T1 and T2 is one port of the hybrid double-unit sub-module; and the joint point of T2 and T4 is the other port of the hybrid double-unit sub-module. The hybrid double-unit sub-module can simultaneously replace two half-bridge sub-modules, and has negative voltage characteristics of a full-bridge sub-module. With the hybrid double-unit sub-module adopted, the utilization rate of direct voltage can be improved, and the capacity of a system can be improved.

Improved optical interferometric modulators have a small waveguide spacing so that the waveguide pair are close to the central electrode, to enhance electro-optic interaction. Asymmetric waveguides with differential indices are used to effectively de-couple the waveguide pair. Multiple sections of asymmetric waveguide pairs with alternating differential indices are used to achieve chirp-free operation. Another version of the device utilizes transmission-line electrode that weave closer to one of the waveguide pair alternately between sections. Another version of the device utilizes waveguide structure that one of the waveguide is closer to the central electrode in alternate section. To improve efficiency further, a DC bias is provided on the outer electrodes configured as an RF-ground but DC-float electrodes. Another improvement is to have a slot is cut underneath the waveguide region to effectively reduce to thickness of the substrate. These improvements lead to higher modulator efficiency.

A high efficiency optical feedback modulator and method of operation are provided. The high efficiency optical feedback modulator (30) includes an optical modulator (52) and an optical feedback system (54). The optical modulator (52) includes first and second optical inputs (66a, 68a) and first and second optical outputs (66b, 68b). The optical feedback system (54) is coupled between the second optical output (68b) and the second optical input (68a). The second optical input (68a) receives an optical feedback signal (70) from the optical feedback system (54). The first optical input (66a) receives an input light beam (56). The input light beam (56) and the optical feedback signal (70) are modulated with an electronic input signal (26a) to produce a high modulation depth optical signal (36) output from the first optical output (66b). The high efficiency optical feedback modulator (30) achieves a slope efficiency that is an order of magnitude better than conventional optical modulators, corresponding to an RF link gain improvement of 100 times better than conventional optical modulators.

The invention discloses a method for enhancing the broadband interference spectral resolution and a spectrograph. The method for enhancing the broadband interference spectral resolution comprises the steps that after dispersion is conducted on a broadband spectrum, continuous monochromatic spectrums are obtained; interference measurement is conducted on the monochromatic spectrums, so that monochromatic spectrum interferograms are obtained; resolution enhancement is conducted on each monochromatic spectrum interferogram so that the spectral resolution for spectrum reconstruction of each monochromatic spectrum interferogram can be improved. The broadband spectrum is changed into a series of narrowband spectrums, so that the interferogram modulation degree of each narrowband spectrum is improved; on the basis of the maximum optical path difference, the optimal path difference is further increased through the method for enhancing the interference spectral resolution, and therefore the spectrum with a higher resolution is obtained.

A device for pretreating a signal (S1) to be transmitted over a transmission path, wherein the transmission path comprises a band-pass filter (14) whose pass-band width is smaller than a predetermined bandwidth and a non-linear amplifier (16), includes a linearization means (20) for performing a linearization of the signal (S1) to be transmitted before the transmission of the same, such that a non-linearity caused by the non-linear amplifier (16) is counteracted. Further, the device includes a signal-shaping means (22) downstream to the linearization means (20) comprising a frequency response such that the overall frequency response of the signal-shaping means (22) and the band-pass filter (14) corresponds to the frequency response of a filter whose pass-band width is at least equal to the predetermined bandwidth.

A flow-through rotary damper assembly providing highly efficient, essentially laminar fluid flow therethrough is provided. The rotary damper assembly includes a cylindrical outer body and a cylindrical inner body that are rotatable in relation to one another. The outer body defines apertures in relation to one another to allow fluid flow without requiring fluid direction change. The inner body defines a flow passage having inlet and outlet apertures that may be aligned with the apertures of the outer body to allow fluid flow therethrough, or may be rotated out of alignment to block fluid flow. The outer body includes an aperture on one end to allow fluid flow to a third compartment. The inner body also includes an end aperture that may be aligned therewith. The damper provides selectable fluid flow between each of the compartments depending on the relative position of the cylindrical inner body member.

What is provided is a system for maintaining acceptable error rates in a MUD-enabled ad-hoc network. In this system the power spread associated with all of the nodes is maintained within the dynamic range of the system, for instance 30 dB. Also, the signal-to-noise ratio at an intended receiver is maintained above a predetermined minimum SNR, for instance above 5 dB. If the dynamic range rule is not met, then the power at the transmitting node is attenuated such that the dynamic range rule is met, checking to see that the minimum SNR rule is also met, or the transmission from this node is pulled. If there is no power control solution, then power aware scheduling is applied. Alternatively, only power aware scheduling is utilized.

There is described an RF bidirectional communication device utilizing active load modulation, the device comprising (a) a resonance circuit including an antenna (326), and (b) a control unit (322) for controlling communication of the device, including switching between a transmission mode and a receiving mode, wherein the control unit is adapted to (c) modify a configuration of the resonance circuit such that the resonance circuit has a first resonance frequency (f0) when the device is in the transmission mode and a second resonance frequency (f0+Δf) when the device is in the receiving mode, and (d) modify the configuration of the resonance circuit such that a Q-factor of the resonance circuit is periodically decreased while the device is in the transmission mode. There is also described a corresponding method and a system comprising a RF device and a reader / writer device. Furthermore, there is described a computer program and a computer program product.

Methods of operating a frequency-converted laser source are disclosed. According to particular disclosed embodiments, a laser diode is driven in a pulsed mode to define pixel intensity values corresponding to desired gray scale values of image pixels in an image plane of the laser source. The pixel intensity values are a function of a laser control signal comprising a discontinuous pulse component, a relatively constant intensity component I, and a continuously variable intensity component I*. The pulse width w of the discontinuous pulse component is selected from a set of discrete available pulse widths according to a desired pixel gray scale value. A low-end pulse width w of the set of available pulse widths is established for a range of low-end pixel gray scale values and progressively larger pulse widths w are established for ranges of progressively higher pixel gray scale values. The relatively constant intensity component I makes a relatively insignificant contribution to pixel intensity at the low-end pulse width w for the range of low-end pixel gray scale values and assumes a non-zero value for enhanced conversion efficiency at the progressively larger pulse widths w established for the higher pixel gray scale values. The continuously variable intensity component I* varies according to the desired gray scale value of the selected pixel and the contributions of the relatively constant intensity component I and the pulse width w to pixel intensity.

Embodiments of the present disclosure provide a single radio frequency double-stream transmission apparatus, wherein the apparatus includes: a radio frequency link, a reactance control circuit, a parasitic reactor, an active antenna and an even number M of parasitic antennas, wherein M is larger than 2; the radio frequency link is configured to generate a radio frequency signal; the active antenna is connected with the radio frequency link, the parasitic antennas are respectively connected with the parasitic reactor, the distances from the parasitic antennas to the active antenna are the same, and the radian between adjacent parasitic antennas is360Mdegrees;the parasitic reactor may be adjusted by the reactance control circuit to make the reactance values of any pair of parasitic antennas in mirror symmetry via the active antenna be different and the reactance values of the rest pairs of parasitic antennas in mirror symmetry via the active antenna be equal respectively.

The invention discloses a hybrid modular multi-level railway power regulator and a control method and system thereof. The hybrid modular multi-level railway power regulator comprises four phase units which are connected in parallel, each phase unit is formed by connecting an upper bridge arm and a lower bridge arm through a bridge arm inductor, the upper bridge arm and the lower bridge arm are formed by connecting a plurality of half-bridge sub-modules and full-bridge sub-modules in series, and the middle points of the bridge arms of the phase units are connected with an alternating current traction network. According to the hybrid modular multi-level railway power regulator, half-bridge and full-bridge sub-modules are mixed, so that the modulation degree of a converter is increased, and the problem of RPC over-modulation caused by the voltage rise of the traction network is effectively solved.

The invention belongs to the technical field of electronic materials and devices, and discloses a dielectric adjustable compound microwave ceramic material and a preparation method thereof. The compound microwave ceramic material is prepared by compounding AMP2O7 with BTO. The components of the compound microwave ceramic material and the percentage compositions of the components by weight are as follows based on the total weight of the compound microwave ceramic material: 50.0 to 97.5 percent of BaTiO3; and 2.5 to 50.0 percent of AMP2O7, in which A is Ca or Sr, and M is Zn or Cu. The traditional electronic ceramic preparation process adopted is simple; the cost is low; the material system is environment-friendly without toxicity or side effect; the compound microwave ceramic material has remarkable performance, and is applicable for development and design of adjustable microwave devices.