10611 results about "Phase shifted" patented technology

A three-dimensional imaging and display system is provided in which user input is optically detected in an imaging volume by measuring the path length of an amplitude modulated scanning beam as a function of the phase shift thereof. Visual image user feedback concerning the detected user input is presented.

An audio signal decorrelator for deriving an output audio signal from an input audio signal has a frequency analyzer for extracting from the input audio signal a first partial signal descriptive of an audio content in a first audio frequency range and a second partial signal descriptive of an audio content in a second audio frequency range having higher frequencies compared to the second audio frequency range. A partial signal modifier for modifies the first and second partial signals, to obtain first and second processed partial signals, so that a modulation amplitude of a time variant phase shift or time variant delay applied to the first partial signal is higher than that applied to the second partial signal, or for modifying only the first partial signal. A signal combiner combines the first and second processed partial signals, or combines the first processed partial signal and the second partial signal, to obtain an output audio signal.

An embodiment of the present invention provides an antenna system, comprising a plurality of non-uniformly spaced antenna elements arranged substantially linearly, a power divider for dividing transmit power thereby coupling signals to the plurality of antenna elements, a phase shifter capable of phase shifting the signals between the power divider and the plurality of antenna elements such that radiated signals from each antenna element add coherently such that the radiated electromagnetic energy may be focused at a focal point in the near field region or in the Fresnel region of the antenna system. An embodiment of the present invention may also provide at least one additional receive antenna element capable of receiving signals backscattered from at least one RFID tag located in the near field of the focused array and the divider may create substantially equal power levels feeding each antenna element. The antenna elements may be similar or identical and each element may be oriented such that the individual element main beam may point in a unique direction.

A novel apparatus and method for a fully digital quadrature architecture for a complex modulator. The complex modulator can substitute for existing prior art analog quadrature modulator structures and those based on a digital polar architecture (r, θ). The modulator effectively operates as a complex digital-to-analog converter where the digital inputs are given in Cartesian form, namely I and Q representing the complex number I+jQ, while the output is a modulated RF signal having a corresponding amplitude and phase shift. The phase shift being with respect to a reference phase dictated by the local oscillator, which is also input to the converter / modulator. Several embodiments are provided including modulators incorporating dual I and Q transistor arrays, a single shared I / Q transistor array, modulators with single ended and differential outputs and modulators with single and dual polarity clock and I / Q data signals.

Methods for compensating for phase shifts of a communication signal. The methods involve determining a first reference signal (Vref-1) at a first location along a transmission path and a second reference signal (Vref-2) at a second location along the transmission path. Vref-2 is the same as Vref-1. At the first location, a first phase offset is determined using Vref-1 and a first communication signal. At the second location, a second phase offset is determined using Vref-2 and a second communication signal. A phase of a third communication signal is adjusted at the second location using the first and second phase offsets to obtain a modified communication signal. The first, second, and third communication signals are the same communication signal obtained at different locations along the transmission path.

Local oscillator circuitry for an antenna array is disclosed. The circuitry includes an array of rotary traveling wave oscillators which are arranged in a pattern over an area and coupled so as to make them coherent. This provides for a set of phase synchronous local oscillators distributed over a large area. The array also includes a plurality of phase shifters each of which is connected to one of the rotary oscillators to provide a phase shifted local oscillator for the array. The phase shifter optionally includes a cycle counter that is configured to count cycles of the rotary oscillator to which it is connected and control circuitry that is then operative to provide a shifted rotary oscillator output based on the count from the cycle counter. A system and method for operating a true-time delay phased array antenna system. The system includes a plurality of antenna element circuits for driving or receiving an rf signal from the elements of the array. Each element circuit has a transmit and a receive path and a local multiphase oscillator, such as a rotary traveling wave oscillator. Each path has an analog delay line for providing a true-time delay for the antenna element. Preferably, the analog delay line is a charge coupled device whose control nodes are connected to phases of the local multiphase oscillator to implement a delay that is an integer number local multiphase oscillator periods. A fractional delay is also included in the path by using a sample and hold circuit connected to a particular phase of the oscillator. By delaying each antenna element by a true time delay, broadband operation of the array is possible.

Optical coherence tomography with 3D coherence scanning is disclosed, using at least three fibers (201, 202, 203) for object illumination and collection of backscattered light. Fiber tips (1, 2, 3) are located in a fiber tip plane (71) normal to the optical axis (72). Light beams emerging from the fibers overlap at an object (122) plane, a subset of intersections of the beams with the plane defining field of view (266) of the optical coherence tomography apparatus. Interference of light emitted and collected by the fibers creates a 3D fringe pattern. The 3D fringe pattern is scanned dynamically over the object by phase shift delays (102, 104) controlled remotely, near ends of the fibers opposite the tips of the fibers, and combined with light modulation. The dynamic fringe pattern is backscattered by the object, transmitted to a light processing system (108) such as a photo detector, and produces an AC signal on the output of the light processing system (108). Phase demodulation of the AC signal at selected frequencies and signal processing produce a measurement of a 3D profile of the object.

A wide-bandwidth antenna with antenna pattern control includes a radiator and a feed. The radiator includes two or more volumetric radiating elements. The feed includes two or more feed units, the feed units configured to provide wave signals to the volumetric radiating elements. The feed units provide an independent signal for each radiating element. The wave signals can be fed out of phase to each other. Depending on the dielectric filler inside the volume of the antenna and the phase shift between feeds, the pattern can be modified electronically leading to pattern control. The radiating elements are spaced at a distance at least one order of magnitude smaller than half of an operational wavelength of the antenna. At least one electrically conductive element of the antenna is capable of conducting a current that generates a magnetic field. The magnetic field lowers the total reactance of the antenna, thereby resulting in enhanced performance of the antenna in terms of bandwidth, gain, and pattern control. The volumetric design allows miniaturization of the antenna.

A transmit and receive circuit for use in power line communication devices is provided. One embodiment of the circuit includes a receive channel with a first delay circuit coupled to a first switch having an open configuration and a closed configuration a first switch. The circuit also may include a transmit channel coupled to the receive channel at a node and including a second delay circuit coupled to a second switch having an open configuration and a closed configuration. When the switch of either channel is closed, the switch of the other channel is open. Data signals traversing either channel when that channel's switch is closed, are phase shifted approximately three hundred and sixty degrees and conducted back to the node.

An embodiment of the present invention provides an RFID tag reading system, comprising an antenna system associated with a portal through which said RFID tag may pass, said antenna system comprising: a plurality of non-uniformly spaced antenna elements arranged substantially linearly; a power divider for dividing transmit power thereby coupling signals to said plurality of antenna elements; and a beamforming network capable of phase shifting the signals between the power divider and the plurality of antenna elements such that radiated signals from each antenna element add coherently such that the radiated electromagnetic energy is focused at a focal point in the near field region or in the Fresnel region of said antenna system.

An apparatus for estimating a plurality of channels from a plurality of distinct transmitting points, wherein an input signal includes a super position of signals based on a first pilot sequence transmittable from a first transmitting point and on a second pilot sequence transmittable from a second transmitting point, the first pilot sequence and the second pilot sequence having a phase shift to each other, comprises a transformer, which is operative to translate phase shifts between the first and the second pilot sequence into a delay, so that a first group of a set of discrete values of the transformed signal includes channel information of a first channel and that a second group of a set of discrete values includes channel information of a second channel, a selector for selecting the first group from the set of discrete values and for selecting the second group from the set of discrete values to obtain selected groups, and means for determining channel information for the plurality of channels based on the selected groups. The selection of groups at the output of the transformer for obtaining channel information for the channel allows the construction of a simplified receiver.

A receiver circuit suppresses effects of “benign” impairment from the calculation of received signal quality estimates, such that the estimate depends primarily on the effects of non-benign impairment. For example, a received signal may be subject to same-cell and other-cell interference plus noise, which is generally modeled using a Gaussian distribution, and also may be due to certain forms of self-interference, such as quadrature phase interference arising from imperfect derotation of the pilot samples used to generate channel estimates for the received signal. Such interference generally takes on a distribution defined by the pilot signal modulation, e.g., a binomial distribution for binary phase shift keying modulation. Interference arising from such sources is relatively “benign” as compared to Gaussian interference and thus should be suppressed or otherwise discounted in signal quality calculations. Suppression may be based on subtracting benign impairment correlation estimates from total impairment correlation estimates, or on filtering the benign impairment in channel estimation.

A pulsed light source in used conjunction with a ramping scanning mechanism for phase-shift and vertical-scanning interferometry. The pulse length and the scanning velocity are selected such that a minimal change in OPD occurs during the pulse. As long as the duration of the pulse is shorter than the detector's integration time, the effective integration time and the corresponding phase shift are determined by the length of the pulse, rather than the detector's characteristics. The resulting minimal phase shift produces negligible loss of fringe modulation, thereby greatly improving signal utilization during phase-shifting and vertical-scanning interferometry.

A method of repairing a semiconductor phase shift mask comprises first providing a semiconductor mask having a defect and then illuminating the mask to create an aerial image of the mask. Subsequently, the aerial image of the mask is analyzed and the defect in the mask is detected from the aerial image. An ideal mask image is defined and compared to the aerial image of the defective mask to determine the repair parameters. Unique parameters for repairing the mask defect are determined by utilizing the aerial image analysis and a look-up table having information on patch properties as a function of material deposition parameters. The mask is then repaired in accordance with the parameters to correct the mask defect. A patch of an attenuated material may be applied to the mask or a predetermined amount of material may be removed from the mask. The aerial image of the repair is analyzed to determine whether the repair sufficiently corrects the defect within predetermined tolerances.

In this electromagnetic wave frequency filter, an electromagnetic wave of a predetermined frequency matching a resonant frequency of a resonator 41 is transmitted from an input waveguide 2 to an output waveguide 3 through the resonator 41, and is outputted from a drop port P31. This filter has an input-waveguide-side reflector 211 and an output-waveguide-side reflector 311, which reflect the electromagnetic wave of the predetermined frequency. The electromagnetic wave frequency filter satisfies the following relation:Qinb / (1−cos θ1)<<Qv,Qinb / (1−cos θ1)=Qinr / (1−cos θ2),θ1, θ2≠2Nπ(N=0, 1, . . . ),where θ1 is a phase shift amount of the electromagnetic wave reflected by the input-waveguide-side reflector 211, θ2 is a phase shift amount of the electromagnetic wave reflected by the output-waveguide-side reflector 311, Qinb is a Q-factor between the resonator 41 and the input waveguide 2, Qinr is a Q-factor between the resonator 41 and the output waveguide 31, and Qv is a Q-factor between the resonator 41 and free space.

A power converter system for supplying an output voltage is provided. The power converter system is adapted to operate in a normal mode and a fault mode. The system comprises a plurality of bridges and a plurality of transformers. The system further comprises a plurality of dc link capacitors, each coupled across a corresponding bridge. The system also includes a controller adapted for, during the normal mode, switching each bridge with a respective normal phase shift. During the fault mode, the controller is adapted for switching each of the remaining ones of the bridges with a respective adjusted phase shift to generate the output voltage. During the fault mode, at least one of the plurality of bridges is bypassed.

A transmit and receive circuit for use in power line communication devices is provided. One embodiment of the circuit includes a receive channel with a first delay circuit coupled to a first switch having an open configuration and a closed configuration a first switch. The circuit also may include a transmit channel coupled to the receive channel at a node and including a second delay circuit coupled to a second switch having an open configuration and a closed configuration. When the switch of either channel is closed, the switch of the other channel is open. Data signals traversing either channel when that channel's switch is closed, are phase shifted approximately three hundred and sixty degrees and conducted back to the node.

A family of soft-switched, full-bridge pulse-width-modulated (FB PWM) converters provides zero-voltage-switching (ZVS) conditions for the turn-on of the bridge switches over a wide range of input voltage and output load. The FB PWM converters of this family achieve ZVS with the minimum duty cycle loss and circulating current, which optimizes the conversion efficiency. The ZVS of the primary switches is achieved by employing two magnetic components whose volt-second products change in the opposite directions with a change in phase shift between the two bridge legs. One magnetic component always operates as a transformer, where the other magnetic component can either be a coupled inductor, or uncoupled (single-winding) inductor. The transformer is used to provide isolated output(s), whereas the inductor is used to store the energy for ZVS.

A stepped reflector for being illuminated by at least one multiple-band feed is provided. The reflector includes a central region and a first annular region with an annular width of w. The first annular region is axially stepped a height h above the central region, where h is approximately equal tom×[Φ±(ϕ⁡(Θ=0)-ϕ⁡(Θ=Θ0))]×π180×λ2⁢π×12,where m is a positive odd integer, Φ is a desired amount of phase shift of an outer region of a phase front for reflecting off of the reflector, φ is a feed phase contribution for an angle Θ, and Θ0 is an angle formed between an axis of the at least one feed and a line connecting a phase center of the at least one feed and an inner edge of the at least one annular region.The central region and the annular region of the reflector may be parabolically curved or may alternately be shaped. The reflector may be fed by one or more multiple-band horn antennas.

A structured light system for object ranging / measurement is disclosed that implements a trapezoidal-based phase-shifting function with intensity ratio modeling using sinusoidal intensity-varied fringe patterns to accommodate for defocus error. The structured light system includes a light projector constructed to project at least three sinusoidal intensity-varied fringe patterns onto an object that are each phase shifted with respect to the others, a camera for capturing the at least three intensity-varied phase-shifted fringe patterns as they are reflected from the object and a system processor in electrical communication with the light projector and camera for generating the at least three fringe patterns, shifting the patterns in phase and providing the patterns to the projector, wherein the projector projects the at least three phase-shifted fringe patterns sequentially, wherein the camera captures the patterns as reflected from the object and wherein the system processor processes the captured patterns to generate object coordinates.

An apparatus for estimating a plurality of channels from a plurality of distinct transmitting points, wherein an input signal includes a super position of signals based on a first pilot sequence transmittable from a first transmitting point and on a second pilot sequence transmittable from a second transmitting point, the first pilot sequence and the second pilot sequence having a phase shift to each other, comprises a transformer, which is operative to translate phase shifts between the first and the second pilot sequence into a delay, so that a first group of a set of discrete values of the transformed signal includes channel information of a first channel and that a second group of a set of discrete values includes channel information of a second channel, a selector for selecting the first group from the set of discrete values and for selecting the second group from the set of discrete values to obtain selected groups, and means for determining channel information for the plurality of channels based on the selected groups. The selection of groups at the output of the transformer for obtaining channel information for the channel allows the construction of a simplified receiver.

The invention relates to a method of signal analysis that determines the location of a transmitter and to devices that implement the method. The method includes receiving by at least three receivers, from a transmitter, a first continuous-time signal having a first channel. The first channel includes a first plurality of signal carriers having known relative initial phases and having known frequencies which are periodically spaced and which are orthogonal to one another within a first frequency range. The signal analysis method also includes determining the phase shifts of the carriers of the first channel resulting from the distance the carriers traveled in reaching the first receiver. Analysis of the phase shifts yields time difference of arrival information amongst the receivers, which is further processed to determine the location of the transmitter.

A passive harmonic switch mixer is shown that is immune to self mixing of the local oscillator greatly reducing leakage noise, pulling noise, and flicker noise when used in a direct conversion receiver or direct conversion transmitter circuit. The passive harmonic switch mixermixes an input signal received on an input port with an in-phase oscillator signal and a quadrature-phase oscillator signal and outputs an output signal on an output port. Because the quadrature-phase oscillator signal is the in-phase oscillator signal phase shifted by 90 °, the passive harmonic switch mixer operates with a local oscillator running at half the frequency of the carrier frequency of an RF signal. Additionally, because the passive harmonic switch mixer has no active components, the DC current passing through each switch device is reduced and the associated flicker noise of the mixer is also greatly reduced.

The invention relates to the field of X-ray differential phase contrast imaging. For scanning large objects and for an improved contrast to noise ratio, an X-ray device (10) for imaging an object (18) is provided. The X-ray device (10) comprises an X-ray emitter arrangement (12) and an X-ray detector arrangement (14), wherein the X-ray emitter arrangement (14) is adapted to emit an X-ray beam (16) through the object (18) onto the X-ray detector arrangement (14). The X-ray beam (16) is at least partial spatial coherent and fan-shaped. The X-ray detector arrangement (14) comprises a phase grating (50) and an absorber grating (52). The X-ray detector arrangement (14) comprises an area detector (54) for detecting X-rays, wherein the X-ray device is adapted to generate image data from the detected X-rays and to extract phase information from the X-ray image data, the phase information relating to a phase shift of X-rays caused by the object (18). The object (18) has a region of interest (32) which is larger than a detection area of the X-ray detector (18) and the X-ray device (10) is adapted to generate image data of the region of interest (32) by moving the object (18) and the X-ray detector arrangement (14) relative to each other.

A quantum cryptographic key distribution (QKD) system splits discrete light signals from a laser source into a pair of light pulses that are orthogonally polarized with respect to each other, imparts a phase shift to one or both of these separate pulses during their round trip from the sender to the receiver and back, assures that the return pulses from the receiver are attenuated to single-photon pulses, recombines the phase-shifted pulses at the sender, and then detects from the recombined signal its polarization state, which is representative of the net phase shift imparted by the sender and receiver. The phase modulator at the receiver transmits only one polarization (e.g., vertical), but is used in a manner that permits it to equally modulate both polarization components of an arriving pulse. In this arrangement, when both components of a pulse reach the phase modulator at the receiver, they are both entirely vertically polarized and a phase shift is imparted at that time. This has the advantage that the effect of any time variation or phase errors in the phase modulator will be the same on both components. The key information is decoded at a detection stage at the sender that uses two detectors, one of which detects a first polarization state corresponding to the phase difference between the two phase shifts being 0 and the other of which detects a second polarization state corresponding to the phase difference between the two phase shifts being pi.