Showing papers on "Reflector (antenna) published in 2011"

Transparent Reflector Plate For Rapid Thermal Processing Chamber

Abstract: The present invention generally relates to methods and apparatus for processing substrates. Embodiments of the invention include apparatuses for processing a substrate comprising a ceramic reflector plate, which may be optically transparent. The reflector plate may include a reflective coating and be part of a reflector plate assembly in which the reflector plate is assembled to a baseplate.

Cryogenic 2–13 GHz Eleven Feed for Reflector Antennas in Future Wideband Radio Telescopes

Abstract: The system design of a cryogenic 2-13 GHz feed is considered with emphasis on its application in future wideband radio telescope systems. The feed is based on the so-called Eleven antenna and the design requires careful integration of various sub-designs in order to realize cryogenic operation. The various sub-designs include the electrical design of the Eleven antenna, design of the critical center puck, alternative solutions for integrating the Eleven antenna with low-noise amplifiers (LNAs), mechanical and cryogenic design and tests, and system noise temperature estimation and measurements. A great deal of simulated and measured results are presented throughout this paper, including the electrical, mechanical and cryogenic performance, and an assessment of the system noise temperature. The objective of this work is to present a good feed candidate that is well-suited for VLBI2010 and SKA radio telescopes. Further developments needed to completely fulfill the requirements for these future wideband radio telescopes are also discussed.

An Optimal Beamforming Strategy for Wide-Field Surveys With Phased-Array-Fed Reflector Antennas

Abstract: An optimal beamforming strategy is proposed for performing large-field surveys with dual-polarized phased-array-fed reflector antennas. This strategy uses signal-processing algorithms that maximize the beam sensitivity and the continuity of a field of view (FOV) that is formed by multiple closely overlapping beams. A mathematical framework and a newly developed numerical approach are described to analyze and optimize a phased array feed (PAF) system. The modeling approach has been applied to an experimental PAF system (APERTIF prototype) that is installed on the Westerbork Synthesis Radio Telescope. The resulting beam shapes, sensitivity, and polarization diversity characteristics (such as the beam orthogonality and the intrinsic cross-polarization ratio) are examined over a large FOV and frequency bandwidth. We consider weighting schemes to achieve a conjugate-field matched situation (max. received power), maximum signal-to-noise ratio (SNR), and a reduced SNR scenario but with constraints on the beam shape. The latter improves the rotational symmetry of the beam and reduces the sensitivity ripple, at a modest maximum sensitivity penalty. The obtained numerical results demonstrate a very good agreement with the measurements performed at the telescope.

Conjunction of fiber solar cells with groovy micro-reflectors as highly efficient energy harvesters

Abstract: Solar cells are the most effective approach for sustainable energy to meet the world's increasing needs in energy. However, their large-scale applications have been limited by low cost performance, supply of raw materials, complex preparation processes and the possible pollutions produced during processing. Here we introduce a novel fiber solar cell housed in a simple and low-cost parabolic-shape reflector, which can effectively capture diffuse light from all directions. The maximum efficiency of the fiber based dye-sensitized solar cells alone reached 7.02%. Furthermore, the maximum power output was enhanced by a factor of two and five, respectively, when the fiber was in conjunction with a diffuse reflector or a micro-light concentrating groove.

The FengYun-3 Microwave Radiation Imager On-Orbit Verification

Abstract: The Microwave Radiation Imager (MWRI) on board the FengYun-3A/B satellites observes the Earth atmosphere at 10.65, 18.7, 23.8, 36.5, and 89.0 GHz with each having dual polarization. Its calibration system is uniquely designed with a main reflector viewing both cold and hot calibration targets. Two quasi-optical reflectors are used to reflect the radiation from the hot load and cold space to the main reflector. In the MWRI calibration process, a radiation loss in the beam transmission path must be taken into account. The loss factor in the hot load transmission path is derived using the antenna pattern data measured on ground and satellite data observing over the Amazon forest where the scene temperature is steady and close to the hot load. The instrument nonlinearity factors at different channels are also evaluated over a wide range of brightness temperatures and compared with the results from the ground vacuum test. After a cross-calibration with Windsat data, atmospheric products are derived from MWRI brightness temperatures with the accuracy similar to those from the legacy sensors (e.g., the Special Sensor Microwave/Imager).

Estimating DoA From Radio-Frequency RSSI Measurements Using an Actuated Reflector

Abstract: We describe a proof-of-concept device and method to estimate the direction-of-arrival (DoA) of a radio signal by a receiver that is suitable for wireless sensor network (WSN) applications. The device estimates the DoA by identifying the peak of received signal strength indicator (RSSI) measurements using an actuated parabolic reflector. Automatic localization is an important requirement for deployment of wireless sensor networks. Localization from distance measurement alone is a challenging problem, but becomes easier if relative angular position measurements between pairs of radio nodes are available. Methods of DoA estimation such as phased arrays are unsuitable for wireless sensor networks due to size, cost and complexity limitations. The device and the algorithm we describe is compact and simple enough to be suitable for WSNs. Experimental results show that the error in the measured DoA has a mean smaller than 4° and standard deviation of smaller than 8°, in both indoor and outdoor environments in line of sight situations. Presence of moving objects in the vicinity of the transceivers seem to have an adverse effect of the measurement accuracy.

Renal denervation catheter employing acoustic wave generator arrangement

Abstract: A transducer supported by a positioning arrangement is placed within a renal artery at a desired location that is a predetermined distance from a reflector equal to an odd number of quarter wavelengths of acoustic energy emitted by the transducer. The positioning arrangement is actuated to transition from a low-profile introduction configuration to a deployed configuration within the renal artery thereby stabilizing the transducer at a desired location. Acoustic energy is emitted by the transducer so that it propagates axially along an outer surface of the target vessel to impinge the reflector, which can be biological or artificial. The emitted energy builds up to resonance at a point of reflection defined by a location of the reflector, and the amount of energy build up is sufficient to ablate perivascular renal nerves in the vicinity of the reflector.

Coupler for coupling gyrotron whispering gallery mode RF into HE11 waveguide

Abstract: A cylindrical waveguide with a mode converter transforms a whispering gallery mode from a gyrotron cylindrical waveguide with a helical cut launch edge to a quasi-Gaussian beam suitable for conveyance through a corrugated waveguide. This quasi-Gaussian beam is radiated away from the waveguide using a spiral cut launch edge, which is in close proximity to a first mode converting reflector. The first mode converting reflector is coupled to a second mode converting reflector which provides an output free-space HE11 mode wave suitable for direct coupling into a corrugated waveguide. The radiated beam produced at the output of the second mode converting reflector is substantially circular.

Miniaturization of Slot Antennas Using Slit and Strip Loading

Abstract: The design of a miniaturized slot antenna with slit loading fed by the CPW line is proposed. It is seen that the loading slits can be located only on the feed side without degradation in cross-pol performance, unlike the microstrip-fed case. This releases the ground plane area above the slot for accommodating electronic circuitry and effectively reduces the antenna size. In addition, the resonant frequency in this case is reduced by a further 4.60%, compared to the slits on both sides. Another topology of the miniaturized antenna is investigated with the slits replaced by strips of metallization on the reverse side of the substrate, which leaves the ground plane area completely free. A high reduction in the slot resonant frequency is also observed in this case, with a reflector being used to increase the forward radiation.

3D RTM angle gathers from source wave propagation direction and dip of reflector

Abstract: Summary Creating an angle gather is a conceptually simple process of plotting reflection amplitudes along the angle. Reflection or opening angle can be directly calculated from source and receiver wave propagation directions or source propagation direction and dip of the reflector. We studied a cost effective approach to generate 3D Reverse Time Migration (RTM) angle gathers from source wave propagation direction and dip information. This is a mapping process of the shot image onto an angle and azimuth plane using the most energetic arrivals and their amplitudes and propagation directions.

On Chip Plasmonic Monopole Nano-Antennas and Circuits

Abstract: Analogues of many radio frequency (RF) antenna designs such as the half-wave dipole and Yagi-Uda have been successfully adapted to the optical frequency regime, opening the door for important advances in biosensing, photodetection, and emitter control. Examples of monopole antennas, however, are conspicuously rare given the element's extensive use in RF applications. Monopole antennas are attractive as they represent an easy to engineer, compact geometry and are well isolated from interference due the ground plane. Typically, however, the need to orient the antenna element perpendicular to a semi-infinite ground plane requires a three-dimensional structure and is incompatible with chip-based fabrication techniques. We propose and demonstrate here for the first time that monopole antenna elements can be fashioned out of single element nanoparticles fabricated in conventional planar geometries by using a small nanorod as a wire reflector. The structure offers a compact geometry and the reflector element provides a measure of isolation analogous to the RF counterpart. This isolation persists in the conductive coupling regime, allowing multiple monopoles to be combined into a single nanoparticle, yet still operate independently. This contrasts with several previous studies that observed dramatic variations in the spectral response of conductively coupled particles. We are able to account for these effects by modeling the system using circuit equations from standard RF antenna theory. Our model accurately describes this behavior as well as the detailed resonance tuning of the structure. As a specific practical application, the monopole resonances are precisely tuned to desired protein absorption bands, thereby enhancing their spectroscopic signatures. Furthermore, the accurate modeling of conductive coupling and demonstrated electronic isolation should be of general interest to the design of complex plasmonic circuits incorporating multiple antennas and other current carrying elements.

High-index-contrast grating reflector with beam steering ability for the transmitted beam.

Abstract: High-index contrast grating mirrors providing wave front control of the transmitted light as well as high reflectivity over a broad bandwidth are suggested and both numerically and experimentally investigated. General design rules to engineer these structures for different applications are derived. Such grating mirrors would have a significant impact on low cost laser fabrication, since a more efficient integration of optoelectronic modules can be achieved by avoiding expensive external lens systems.

Light-emitting diode and method for manufacturing the same

Abstract: A light-emitting diode and method for manufacturing the same are described. The light-emitting diode comprises: a conductive substrate including a first surface and a second surface opposite to the first surface; a reflector structure comprising a conductive reflector layer bonding to the first surface of the conductive substrate and a conductive distributed Bragg reflector (DBR) structure stacked on the conductive reflector layer; an illuminant epitaxial structure disposed on the reflector structure; a first electrode disposed on a portion of the illuminant epitaxial structure; and a second electrode bonded to the second surface of the conductive substrate.

Micro-channel-cooled high heat load light emitting device

Abstract: Micro-channel-cooled UV curing systems and components thereof are provided. According to one embodiment, a lamp head module includes an optical macro-reflector, an array of LEDs and a micro-channel cooler assembly. The array is positioned within the reflector and has a high fill factor and a high aspect ratio. The array provides a high irradiance output beam pattern having a peak irradiance of greater than 25 W/cm2 at a work piece surface at least 1 mm away from an outer surface of a window of the reflector. The micro-channel cooler assembly maintains a substantially isothermal state among p-n junctions of the LEDs at less than or equal to 80° Celsius. The micro-channel cooler assembly also provides a common anode substrate for the array. A thermally efficient electrical connection is formed between the array and the common anode substrate by mounting the array to the micro-channel cooler assembly.

LED roadway luminaire

Abstract: The luminaire comprises a housing including at least one optical module. The optical module has a plurality of light emitting diodes disposed within a reflector. The reflector includes opposed curved longitudinal walls and opposed curved end walls.

Realization of a distributed Bragg reflector for propagating guided matter waves.

Abstract: We report on the experimental study of a Bragg reflector for guided, propagating Bose-Einstein condensates. A one-dimensional attractive optical lattice of finite length created by red-detuned laser beams selectively reflects some velocity components of the incident matter wave packet. We find quantitative agreement between the experimental data and one-dimensional numerical simulations and show that the Gaussian envelope of the optical lattice has a major influence on the properties of the reflector. In particular, it gives rise to multiple reflections of the wave packet between two symmetric locations where Bragg reflection occurs. Our results are a further step towards integrated atom-optics setups for quasi-cw matter waves.

Wideband Beam-Steerable Flat Reflectors via Transformation Optics

Abstract: A conventional parabolic reflector is converted into a flat one based on the discrete coordinate transformation. Instead of general beam-steering techniques, such as off-axis feeding, tilting the feed/reflector, or utilizing phase shift, we show an alternative way to manipulate the reflected emission through tuning transformed dielectrics. The proposed design, only including the conventional dielectric components, has a merit of keeping the flat profile of a compact reflector system while possessing the ability to steer the radiation beams in a wide frequency band.

Acoustic levitation with self-adaptive flexible reflectors.

Abstract: Two kinds of flexible reflectors are proposed and examined in this paper to improve the stability of single-axis acoustic levitator, especially in the case of levitating high-density and high-temperature samples. One kind is those with a deformable reflecting surface, and the other kind is those with an elastic support, both of which are self-adaptive to the change of acoustic radiation pressure. High-density materials such as iridium (density 22.6 gcm−3) are stably levitated at room temperature with a soft reflector made of colloid as well as a rigid reflector supported by a spring. In addition, the containerless melting and solidification of binary In-Bi eutectic alloy (melting point 345.8 K) and ternary Ag-Cu-Ge eutectic alloy (melting point 812 K) are successfully achieved by applying the elastically supported reflector with the assistance of a laser beam.

Led vehicle headlamp

Abstract: The invention relates to a vehicle headlamp (1), comprising a first reflector arrangement, which has at least one stationary reflector (2), a second reflector arrangement, which has at least one reflector (3) that can be adjusted relative to the at least one stationary reflector (2) of the first reflector arrangement, at least two light sources (8, 9), wherein at least one of the light sources (16, 17) is associated with each of the reflectors (2, 3), and wherein each light source (16, 17) has at least one light-emitting diode, and a mounting body (4) for fastening the at least one stationary reflector (2) and the at least two light sources (16, 17), wherein the mounting body (4) comprises a main mounting body (5), on which the at least one stationary reflector (2) is mounted in a stationary manner, and an exchangeable mounting body (6), to which the at least two light sources (16, 17) are fastened, and wherein the at least one adjustable reflector (3) is arranged on the same side of the main mounting body (5) as the at least one stationary reflector (2) and can be adjusted relative to the at least one stationary reflector (2), and wherein the main mounting body (5) has a passage opening (19) for inserting a light-source carrying element (12) from the side facing away from the reflectors (2, 3), wherein the light-source carrying element (12) is connected to the exchangeable mounting body (6) and carries the at least two light sources (16, 17), and wherein the exchangeable mounting body (6) can be detachably fastened to the main mounting body (5) and wherein referencing and/or positioning elements (11, 11') are provided on the exchangeable mounting body (6) and on the main mounting body (5) in order to fasten the two bodies (5, 6) to each other in a positionally accurate manner.

Matrix method for acoustic levitation simulation

Abstract: A matrix method is presented for simulating acoustic levitators. A typical acoustic levitator consists of an ultrasonic transducer and a reflector. The matrix method is used to determine the potential for acoustic radiation force that acts on a small sphere in the standing wave field produced by the levitator. The method is based on the Rayleigh integral and it takes into account the multiple reflections that occur between the transducer and the reflector. The potential for acoustic radiation force obtained by the matrix method is validated by comparing the matrix method results with those obtained by the finite element method when using an axisymmetric model of a single-axis acoustic levitator. After validation, the method is applied in the simulation of a noncontact manipulation system consisting of two 37.9-kHz Langevin-type transducers and a plane reflector. The manipulation system allows control of the horizontal position of a small levitated sphere from -6 mm to 6 mm, which is done by changing the phase difference between the two transducers. The horizontal position of the sphere predicted by the matrix method agrees with the horizontal positions measured experimentally with a charge-coupled device camera. The main advantage of the matrix method is that it allows simulation of non-symmetric acoustic levitators without requiring much computational effort.

Optical connection system with plug having optical turn

Abstract: A connection system and method in which, when a plug portion is mated with a receptacle portion, a reflector in the plug portion can redirect optical signals between an end of an optical fiber in the plug portion and an opto-electronic device, such as a light source or light receiver, in the receptacle portion.

Specular reflector and LED lamps using same

Abstract: A specular reflector and LED lamps using embodiments of the reflector are disclosed. Embodiments of the invention provide a reflector for solid state lamps. The reflector can be a specular reflector. The reflector includes a rigid, polymeric substrate and sputtered metal applied to the substrate. In some embodiments, the metal is silver. In some embodiments, the metal is applied without an intervening base coat. In some embodiments, the substrate is made from or includes an aromatic polyester such as polyarylate. The reflector can include a discontinuous or irregular surface yet still exhibit very high overall reflectivity and efficiency because the metal can be applied without an intervening base coat. In some embodiments, the reflector is used in lamps having a retroreflective optical design.

Swept mode-hopping laser system, methods, and devices for frequency-domain optical coherence tomography

Abstract: In part, the invention relates to frequency-domain optical coherence tomography system. The system includes a tunable laser comprising a laser output for transmitting laser light and a laser cavity having a length L, a gain element disposed within the laser cavity; a tunable wavelength selective element disposed within the laser cavity; a reference reflector disposed outside of the laser cavity; an interferometer in optical communication with the laser output and the reference reflector, wherein the interferometer is configured to transmit a portion of the laser light to a sample and combine light scattered from the sample with light scattered from the reference reflector; and a detector in optical communication with the interferometer that receives the combination of light scattered from the sample and the light scattered from the reference reflector and transforms the combination of light into an electronic signal comprising measurement data with respect to the sample.

Electromagnetic wave absorber

Abstract: PROBLEM TO BE SOLVED: To provide an electromagnetic wave absorber that assures a translucent or lighting property or a ventilation property, while keeping wide-band electromagnetic wave absorption characteristics SOLUTION: The electromagnetic wave absorber 1 has a structure which laminates a plate-shaped resin molding 10 on an electromagnetic wave incidence surface side as an electromagnetic wave absorption layer and a reflector 20 on the backside thereof Magnetic powder 12 is filled inside a resin material 11 that forms the resin molding 10, wherein a filling density thereof increases continuously from the electromagnetic wave incidence surface toward the reflection layer side The reflector 20 has at least one of the air ventilation property and light transmission property, while having a communicative structure in the thickness direction The electromagnetic wave absorption layer has at least one window 3 which pierces part of the upper surface of the reflection layer in the thickness direction COPYRIGHT: (C)2011,JPO&INPIT

Wireless communication apparatus

Abstract: PROBLEM TO BE SOLVED: To obtain a wireless communication apparatus which has a directivity in a specific direction with a simple configuration.SOLUTION: A wireless communication apparatus comprises: a communication antenna 12; a resin case 13 accommodating the communication antenna 12; a reflector 14 for reflecting radio waves radiated by the communication antenna 12; and a mount member for mounting the reflector 14 at each of a plurality of different positions on a side surface of the resin case 13. The reflector 14 is mounted at a predetermined position on the resin case 13 by the mount member, thereby obtaining directivity of the communication antenna 12 in a specific direction.