Abstract: A motion sensing method and apparatus includes a housing enclosing a microwave motion sensor including an antenna, and a security system. The antenna may be a patch antenna which includes microwave radiating elements for transmitting and receiving a microwave signal for sensing motion. A reflector is attached to the housing and positioned above the antenna for downward shaping of the microwave signal. The microwave radiating elements together with the reflector provide a radiation pattern where a main beam is transmitted in a direction orthogonal to a surface of the antenna and a sided lobe is transmitted downward in amplitude below the microwave motion sensor. An alarm circuit indicates when the microwave sensor detects motion in armed mode, and a masking circuit indicates when the microwave sensor detects motion in a mask zone when the security system is unarmed. A second sensor may be positioned beneath the microwave motion sensor.

Abstract: Embodiments of millimeter-wave communication systems and methods for communicating using millimeter-waves are described. In some embodiments, a directional antenna (102) may direct millimeter-wave signals substantially in a horizontal plane (115), and one or more reflectors (104) may be positioned to reflect the millimeter-wave signals to user devices (108).

Abstract: A phased array antenna device is described. The phased array antenna device includes at least one one-dimensional phased array of radiating elements arranged along an array direction, a lens, and a phase control element. The lens is arranged such that divergent beams from the radiating elements are collimated by the lens in a direction orthogonal to the array direction to produce a beam. The phase control element is configured to apply a linear phase gradient to the radiating elements thereby providing one-dimensional electronic beam steering for the antenna device. The antenna device may additionally include one or two mechanical positioners to mechanically move the at least one one-dimensional phased array in directions orthogonal to the array direction, where the phased array enables scanning along the array direction.

Abstract: A coherent near-field array. The array consists of a number of high-gain elements, each of which directs its beam at the desired target area (either mechanically or electronically). Each element is coherently fed, so that the phase relationships between different feeds are constant or slowly varying. The elements in the array may be spaced many wavelengths apart. The array relies on interference to generate a number of power density peaks within the target area.

Abstract: A composite dipole array assembly can have a composite dipole array defined by a plurality of antenna elements and a plurality of non-linear element electrically interconnecting pair of the antenna elements. A reflector can be configured to reflect electromagnetic energy toward the antenna elements. A lens can be configured to focus electromagnetic energy upon the antenna elements. In this manner, the efficiency of the composite dipole array is enhanced.

Abstract: A radome comprises a structure covering an antenna, the structure being substantially transparent to radiation of the antenna in a first direction and being less transparent to radiation of the antenna when deviating from the first direction, thereby imparting a directional profile to radiation of the antenna. The millimeter wave antenna structure comprises a sub-reflector lens, and a reflector, the sub-reflector lens in turn comprising a reflecting metal plate and a lens shaped dielectric material, the lens shaped dielectric material and the reflecting metal plate being shaped together to provide a predetermined radiation illumination pattern on the reflector. A waveguide matching holder connects a circular cross section waveguide via a circular cavity, and a rectangular waveguide feed via a rectangular cavity, the rectangular and the circular cavities being shaped to merge into each other.

Abstract: A deployable lens is provided for an antenna. The lens comprises an array of metallic lens elements formed on a plurality of planar sections of a dielectric substrate, each lens element comprising a first end-fire element directed towards a feed side of the lens, a second end-fire element directed towards a non-feed side of the lens and a section of transmission line for coupling signals between the first and second end-fire elements. The section of transmission line, preferably in the form of a slot-line transmission line, is integrated with the end-fire elements and is of a length determined according to the position of the lens element within the aperture of the lens as deployed. An antenna is also provided comprising a deployable lens according to the present invention.

Abstract: A reflector 38 includes a mirrored surface 48 and a frequency selective surface 46. The frequency selective surface 46 is arranged to reflect radiation of a first frequency band 52 and allow radiation of a second frequency band 50 to pass. The mirrored surface 48 is arranged to reflect radiation of the second frequency band 50. In this manner, the focal power for radiation of the first frequency band 52 is independent to the focal power for radiation of the second frequency band 50. Accordingly, the design of optical components associated with the second frequency band 50 can be undertaken independently of those associated with the first frequency band 52 so as to achieve the optimised focusing for each frequency band.

Abstract: An antenna system and electronic scanning method that employs feed subarray electronic offset beam scanning. The system includes a feed element containing an array of electronic transmitting/receiving elements. The system further includes a reflector for reflecting signals received from the feed element to a target region, and for reflecting signals received from a target region to the feed element. Electronic beam scanning is achieved by activating and deactivating in turn subarrays within the array of transmitting/receiving elements of the feed element.

Abstract: A method of manufacturing a cellular reflectarray antenna arranged in an m by n matrix of radiating elements for communication with a satellite includes steps of determining a delay ?m,n for each of said m by n matrix of elements of said cellular reflectarray antenna using sub-steps of: determining the longitude and latitude of operation, determining elevation and azimuth angles of the reflectarray with respect to the satellite and converting theta0 (?0) and phi0 (?0), determining ??m,n, the pointing vector correction, for a given inter-element spacing and wavelength, determining ??m,n, the spherical wave front correction factor, for a given radius from the central element and/or from measured data from the feed horn; and, determining a delay ?m,n for each of said m by n matrix of elements as a function of ??m,n and ??m,n.

Abstract: Provided are a conductive structure for a high gain antenna and an antenna. A plurality of conductive patterns (512) of the conductive structure are formed on top and bottom surfaces of a dielectric substrate (511) positioned above the antenna and separated from an antenna body (500). A conductive upper structure of the antenna (510) is positioned above the antenna opposite to a ground plane (530) to which the antenna body is fed, separated from the antenna body. A conductive unit structure comprising a plurality of conductive patterns (512) formed on top and bottom surfaces of the dielectric substrate (511) is arranged in a plurality of layers. The conductive structure for a high gain antenna and the antenna can be readily produced by using low cost printed circuit board (PCB) technology, and a gain of the antenna can be increased regardless of a resonance distance between the ground plane of the antenna and the conductive structure disposed above the antenna.

Abstract: A multipath enhancer is disclosed ias including more than one antenna. At least one of a receiver and a transmitter is coupled to the more than one antenna. A selectively reflective surface is adjacent the more than one antenna. A controller is configured to alter the reflectivity of the selectively reflective surface.

Abstract: The present invention is a Radio Frequency (RF) apparatus. The RF apparatus may include a layer of photoconductive material. The RF apparatus may further include a plurality of conductive patches which are disposed within the layer of photoconductive material. The RF apparatus may further include a generating layer. The generating layer may be operatively coupled to the layer of photoconductive material and may be configured for generating light. The generating layer may further be configured for providing the generated light to the layer of photoconductive material. The generated light may be configurable for being provided at a selectable intensity and in a selectable pattern for causing the layer of photoconductive material to be a dynamically controllable optical switch. The dynamically controllable optical switch may be configured for providing a connection between conductive patches included in the plurality of conductive patches.

Abstract: A multiple beam reflector antenna includes at least one reflector, a plurality of feed horns for feeding the at least one reflector, and a metamaterial lens interposed between the plurality of feed horns and the at least one reflector. The metamaterial lens may provide an overlapping element distribution from at least two feed horns of the plurality of feed horns. In one embodiment, the metamaterial lens has an index of refraction between about zero and about one.

Abstract: An antenna array includes at least one transmit array comprising a plurality of metamaterial elements. The antenna array further includes at least one near-field stimulator for inputting electromagnetic signal to the transmit array so that a sub-wavelength target is illuminated with an electromagnetic wave.

Abstract: A method of manufacturing a cellular reflectarray antenna arranged in an m by n matrix of radiating elements for communication with a satellite includes steps of determining a delay ?m,n for each of said m by n matrix of elements of said cellular reflectarray antenna using sub-steps of: determining the longitude and latitude of operation, determining elevation and azimuth angles of the reflectarray with respect to the satellite and converting theta0 (?0) and phi0 (?0), determining ??m,n, the pointing vector correction, for a given inter-element spacing and wavelength, determining ??m,n, the spherical wave front correction factor, for a given radius from the central element and/or from measured data from the feed horn; and, determining a delay ?m,n for each of said m by n matrix of elements as a function of ??m,n and ??m,n.

Abstract: An example apparatus comprises an electromagnetic source, such as an antenna, a metamaterial lens, and a reflector. The antenna is located proximate the metamaterial lens, for example supported by the metamaterial lens, and the antenna is operable to generate radiation when the antenna is energized. The reflector is positioned so as to reflect the radiation through the metamaterial lens. The reflector may have a generally concave reflective surface, for example having a parabolic or spherical cross-section. The metamaterial lens may have an area similar to that of the aperture of the reflector. In some examples, the antenna is located proximate a focal point of the reflector, so that a generally parallel beam is obtained after reflection from the reflector.

Abstract: A wireless communication system includes: a main antenna for radiating an electromagnetic wave to wireless IC chips; a reflecting plate for reflecting the electromagnetic wave from the main antenna to the wireless IC chips; and a control unit which supports the wireless IC chips. The control unit causes a difference between the receiving electromagnetic wave levels of a direct wave from the main antenna and a reflected wave from the reflecting plate received by the antenna of the wireless IC chip.

Abstract: A method of manufacturing a cellular reflectarray antenna arranged in an m by n matrix of radiating elements for communication with a satellite includes steps of determining a delay ?m,n for each of said m by n matrix of elements of said cellular reflectarray antenna using sub-steps of: determining the longitude and latitude of operation, determining elevation and azimuth angles of the reflectarray with respect to the satellite and converting theta0 (?0) and phi0 (?0), determining ??m,n, the pointing vector correction, for a given inter-element spacing and wavelength, determining ??m,n, the spherical wave front correction factor, for a given radius from the central element and/or from measured data from the feed horn; and, determining a delay ?m,n for each of said m by n matrix of elements as a function of ??m,n and ??m,n..

Abstract: A communication system including a first station having at least two first narrow beam antennas and a second station having at least two second narrow beam antennas. The first and second stations establish a first communication path for wireless communication via a pair of first and second narrow beam antennas. When communication via the first communication path is disturbed by obstacles, the first and second stations automatically establish at least one alternative communication path, which is spatially different from the first communication path, for wireless communication using the at least two first narrow beam antennas and the at least two second narrow beam antennas.

Abstract: A radio wave lens antenna device including a semispherical Luneburg lens and a radio wave reflection plate. The radio wave lens antenna device prevents the signal reception sensitivity from being lowered in rain or snow. The radio wave lens antenna device includes a semispherical Luneburg lens 1, a radio wave reflection plate 2 that is larger than the diameter of the lens, an antenna element 3, and a holder 4 that holds the antenna element. The radio wave reflection plate 2 is arranged in an erected state. An ice-snow-water resistant means, which includes a first cover 5 and a second cover 6, prevents rain, snow, and ice from collecting and running off the Luneburg lens.

Abstract: An example apparatus comprises an electromagnetic source, such as an antenna, a metamaterial lens, and a reflector. The antenna is located proximate the metamaterial lens, for example supported by the metamaterial lens, and the antenna is operable to generate radiation when the antenna is energized. The reflector is positioned so as to reflect the radiation through the metamaterial lens. The reflector may have a generally concave reflective surface, for example having a parabolic or spherical cross-section. The metamaterial lens may have an area similar to that of the aperture of the reflector. In some examples, the antenna is located proximate a focal point of the reflector, so that a generally parallel beam is obtained after reflection from the reflector.

Abstract: Embodiments of millimeter-wave communication systems and methods for communicating using millimeter-waves are described. In some embodiments, a directional antenna (102) may direct millimeter-wave signals substantially in a horizontal plane (115), and one or more reflectors (104) may be positioned to reflect the millimeter-wave signals to user devices (108).

Abstract: A composite dipole array assembly can have a composite dipole array defined by a plurality of antenna elements and a plurality of non-linear element electrically interconnecting pair of the antenna elements. A reflector can be configured to reflect electromagnetic energy toward the antenna elements. A lens can be configured to focus electromagnetic energy upon the antenna elements. In this manner, the efficiency of the composite dipole array is enhanced.

Abstract: The terahertz camera has a fixed objective lens (2) and a plurality of detectors (3) positioned at the focal plane of the objective lens (2). Each of the detectors (3) is mounted on a movable support (10) so that the antenna is capable of movement across the focal plane of the objective lens (2) and is provided with a flexible waveguide (4) for connecting the output of the detector (3) with signal processing means. Each detector (3) is also provided with a retroreflector (6) which is reflective at frequencies other than terahertz frequencies. During use of the camera, the retroreflector (6) of each detector (3) is illuminated at non-terahertz frequencies so that the spatial position of each detector (3) and hence the spatial source of signals generated by the detector can be accurately identified. The terahertz camera is particularly suited for use in security installations and in chemical and food processing industries.

Abstract: An antenna mountable on a weapons platform, a communication system and methods of estimating position or range and conducting directional communication. In one embodiment, the antenna includes: (1) a Luneberg lens portion having a substantially planar surface and a convex surface, (2) a radio frequency (RF) reflective layer located proximate the substantially planar surface and (3) a feed horn array located proximate the convex surface and configured to receive RF signals through the Luneberg lens portion and reflected off the RF reflective layer.

Abstract: A system for steering a beam includes a main reflector that receives a signal from a subreflector and reflects the signal in a reflection direction. A prism refracts the signal in a refraction direction. One or more motors adjust a relative orientation between the main reflector and the prism to change a relative orientation between the reflection direction and the refraction direction to steer a beam resulting from the signal.

Abstract: An antenna system with an improved antenna feed system is discussed. This multi-beam antenna system can produce a beam of electromagnetic energy propagating in a desired direction by emitting multiple beams of electromagnetic energy that constructively and destructively interfere. The direction of the net beam of electromagnetic energy can be controlled by adjusting the phase and amplitude of the emitted beams of electromagnetic energy which in turn influences the constructive and destructive interference. The phase and amplitude adjustments can be determined by sampling coordinate rotation or similar functions. Aliased components of these functions can be particularly useful in element reduction.

Abstract: An antenna capable of generating multiple beams that are close together and have side lobes of low level includes optics comprising a single main reflector and a set of primary sources, each source suitable for generating a beam taken up by the optics that transmits it, or suitable for receiving a beam picked up by the optics of the antenna. The main reflector has an aperture of diameter D as a function of the center wavelength of the frequency band of the beams and the half-power beam width of the beams coming from the main antenna element, and a dimensionless number lying in the range 1.5 to 4. The optics present a profile that is modified relative to conventional optics comprising a parabolic main reflector by a correction that imparts an amplitude and phase distribution that is preferably circularly symmetrical, and compliant with a relationship for enlarging the reflected beams.

Abstract: There is disclosed reflect array including a dielectric substrate having a first surface and a second surface. The first surface may support a first array of phasing elements and a second array of phasing element, where the elements of the first array have a first shape and the elements of the second array may have a second shape different from the first shape. The second surface may support a conductive layer.

Abstract: A radar system including a base unit and a radar sensor. The sensor steers a beam in a scanning or tracking manner in both azimuth and elevation. Steering control in azimuth and elevation may be achieved based on configuration settings in the radar sensor processor. The pan-tilt setting may be configured remotely at the base unit. The sensor may include a camera to take panoramic images of the terrain surrounding the sensor, as well as objects-of-interest detected by the system. The sensor is able to transmit radar return information and camera images to the base unit. The base unit is able to display panoramic images and superimpose graphics illustrating a scan profile of the sensor in relationship to the surroundings. The beam steering profile can be controlled by graphically manipulating the profile on the display. This allows configuration of the scanning or tracking profile based on the sensor surroundings.

Abstract: An antenna apparatus is mounted at a wheel rim as a transponder of a system for monitoring a tire pressure or the like, and attached at an end portion of an air valve. The apparatus includes a circuit board having an electronic circuit portion and a grounding conductor layer, a sheet-metal inverse-F type antenna element, a sheet-metal shield case conducting to the grounding conductor layer to cover the electronic circuit portion, and a resin case for accommodating these components. One side surface extending in a longitudinal direction of a space defined between the circuit board and the radiating conductor of the antenna element faces one of sidewalls of a tire, and the other side surface thereof faces a wall surface of the wheel rim with a distance interposed therebetween, the distance being about one-fourth of a wavelength of a radio wave to be used.

Abstract: A phased array antenna device is described. The phased array antenna device includes at least one one-dimensional phased array of radiating elements arranged along an array direction, a lens, and a phase control element. The lens is arranged such that divergent beams from the radiating elements are collimated by the lens in a direction orthogonal to the array direction to produce a beam. The phase control element is configured to apply a linear phase gradient to the radiating elements thereby providing one-dimensional electronic beam steering for the antenna device. The antenna device may additionally include one or two mechanical positioners to mechanically move the at least one one-dimensional phased array in directions orthogonal to the array direction, where the phased array enables scanning along the array direction.

Abstract: A spatially-fed high-power amplifier comprises one or more shaped reflectors to reflect an initial wavefront, and an active array amplifier to amplify the reflected wavefront to generate a high-power planar wavefront. The shaped reflectors provide the reflected wavefront with substantially uniform amplitude when incident on the active array amplifier. The initial wavefront may be a substantially spherical wavefront, and the shaped reflectors may compensate for any amplitude taper of the initial wavefront to provide the reflected wavefront with substantially uniform amplitude components for incident on the active array amplifier. In some embodiments, the shaped reflectors may also contour the illumination to fit the shape of the active array amplifier to help minimize spillover.

Abstract: The antenna feed device (4) of the invention comprises a reflector (2) into which a circular or rectangular section waveguide (8) opens out, the waveguide including a cylindrical or conical radiating aperture (10, 9) at its end. A lens (22) of dielectric material is inserted in part into the inside of the aperture, the portion (23) of the lens (22) projecting out from the waveguide (8) being substantially in the form of a truncated cone and having its smaller diameter end (24) facing outwards. The end (24) includes a central cavity (25) of shape that is given by the solution to a polynomial equation of the “b+ax+cx2+dx3” type, or to a logarithmic equation.

Abstract: Embodiments of High-Power Millimeter-Wave Oscillators are generally described herein. Other embodiments may be described and claimed. In some embodiments, the oscillator includes a polarized partial reflector to at least partially reflect back signals to a reflection array amplifier to help induce oscillation by individual sub-array amplifier elements of the reflection array amplifier. In some other embodiments, the oscillator includes a phase-graded polarization-sensitive reflection plate to at least partially reflect back signals to the reflection array amplifier to help induce an oscillation by the sub-array amplifier elements. In some embodiments, the oscillator includes a reflector and a phase-graded polarized reflection-transmission plate to at least partially pass through signals to the reflector for reflection back to the reflection array amplifier to help induce an oscillation by the sub-array amplifier elements.

Abstract: A reflective Fresnel lens for shaping an incident wave for efficiently delivering the incident wave to an array of receivers, having a wavelength within a predetermined range. The Fresnel lens comprises a ground plate and a plurality of reflective elements formed at various levels of the ground plate. The predetermined range includes millimeter wavelength range, sub-millimeter wavelength range or microwave wavelength range.

Abstract: To perform communication between an antenna and an RFID tag securely. There are generated an interference area with an increased electric field level and an interference area with a decreased level, due to reflections at the upper and lower reflection plates. There are two reflective faces in each reflection plate, which are joined while being shifted from each other by 1/4 wavelength of the electromagnetic wave. Since the two reflective faces are being shifted, the interference area with a decreased electric field level moves on a production line according to a move of a dolly transporting the article. Thus, even if the RFID tag on the article passes through the interference area with a decreased electric field level in a first-half section, it comes to pass the point with recovered electric field level in a latter-half section. Therefore, the antenna can communicate with the RFID tag securely.

Abstract: A vehicle tire interrogation system for interrogating sensors embedded in a vehicle tire. The interrogation system both transmits and receives appropriate RF signals to and from the sensors. The system includes antennas operating at two separate frequency bands that have an input impedance at both frequency bands at 50 ohms, are horizontally polarized, and have a gain at a minimum of 2 dBi at the two frequency bands. The antennas may be printed dual band antennas, such as wideband tapered slot antennas, dual band printed dipoles with reflectors or Yagi-Uda array antennas. The antennas can be embedded in various support structures to protect both the antenna and the vehicle tires.

Abstract: The present invention relates to a microstrip reflective array antenna adopting a plurality of U-slot patches. The microstrip reflective array antenna comprises a reflective disk, a horn antenna and a support. The reflective disk is adapted to reflect microwave signals wherein a plurality of square patches are disposed on the upper surface of a first substrate and a plurality of U-slot patches corresponding to the square patches are disposed on the upper surface of a second substrate. In addition, the lower surface of the first substrate is stacked on the upper surface of a second substrate. The horn antenna is adapted to receive the microwave signals from the reflective disk, and the support is adapted to hold the horn antenna directly above the reflective disk.

Abstract: A reflector-feed assembly for a reflector dish antenna system includes a feeding waveguide and a reflector plate. The feeding waveguide is operable to support the propagation of a signal therethrough, the feeding waveguide having a major axis along which the signal is propagated, and one or more apertures operable to pass the propagating signal therethrough. The reflector plate is coupled to the feeding waveguide, and extends along a major axis which generally orthogonal to the major axis of the feeding waveguide. The reflector plate includes one or more reflecting surfaces which are positioned to reflect signals passing through the one or more apertures, the one or more reflecting surface extending at an acute angle relative to the feeding waveguide major axis.

Abstract: An illuminating-reflector system is provided for transmitting a frequency band in an dispersed beam and a substantially collimated beam. The system includes a secondary reflector configured to transmit a first portion of the frequency band to form the dispersed beam and to reflect a second portion of the frequency band; and a primary reflector configured to receive the second portion of the frequency band reflected from the secondary reflector and to reflect the second portion of the frequency band to form the substantially collimated beam.

Abstract: An antenna device and a method of manufacturing the same are provided. The antenna device can receive a plurality of radio waves, with a small number of parts and at low cost. The antenna device includes a micro lens array and a receiver facing a reflecting surface of the micro lens array. The reflecting surface of the micro lens array is provided with a plurality of different lenses selectively reflecting radio waves with particular frequency ranges to the receiver from among the radio waves transmitted toward the micro lens array.

Abstract: A wireless communication handset and system having improved antenna performance. The system includes a handset body (300) and multiple housing portions with different antenna loading characteristics, for example different materials or shapes, interchangeably mounted on a common portion of the handset body. The handset body (300) includes electrical communications circuitry coupled to an antenna (314), which is adjacent the interchangeable housing portions. A discrete or integrally formed antenna loading feature compensates for the different antenna loading characteristics of the different housing portions to provide optimal antenna performance regardless of the housing portions mounted on the handset body.

Abstract: In an apparatus for measuring a specific absorption rate (SAR) for use in a radio apparatus, a first near magnetic field of a radio wave radiated from a reference radio apparatus is measured in free space, and an SAR of the radio wave radiated from the reference radio apparatus by using a predetermined phantom according to a predetermined measurement method. A transformation factor ? is calculated by dividing the measured SAR by a square value of the measured first near magnetic field, and a second near magnetic field of a radio wave radiated from a radio apparatus to be measured is measured in free space. Then an SAR of the radio wave radiated from the radio apparatus to be measured is estimated and calculated by multiplying a square value of the measured second near magnetic field by the calculated transformation factor ?.

Abstract: A bilayer microstrip reflector antenna is disclosed to include a first dielectric layer, the first dielectric layer having antenna units and phase-delay circuit units overlapped on antenna units, and a second dielectric layer abutting against the first dielectric layer. A better gain-bandwidth is obtained by adjusting the overlapping distance of the antenna units and phase-delay circuit units, side length of antenna units and the dielectric constant and thickness of the two dielectric layers. Surface wave phenomenon is reduced by means of selecting a relatively lower dielectric constant. A satisfactory grounding effect is obtained to reduce radiation from phase-delay circuit units by lowering the second dielectric layer toward the ground.

Abstract: A high performance multi-band antenna reflector having low sidelobe and cross polarization levels, and a superior carrier-to-interference ratio has two concentric zones (12, 14 in a first embodiment and 102, 104 in a second embodiment). In the first embodiment, the outer concentric zone (14) is a frequency selective absorber (20) made of a metallic pattern (22) dimensioned to reflect signals in one frequency band and absorb signals in a second frequency band. In the second embodiment, the outer concentric zone (104) is a frequency selective surface (106) that reflects signals in one frequency band and passes signals in a second frequency bands. Resistance cards (122) overlay the top and bottom sides of the junction between the frequency selective surface (106) and a reflective layer (110) on an inner surface (112) of the central concentric zone (102).

Abstract: A dual polarization active microwave reflector with electronic scanning, configured to be illuminated by a microwave source to form an antenna. The reflector includes two imbricated waveguide arrays, the bottom of each waveguide array being closed by a phase shift circuit carrying out the reflection and the phase shifting of the wave that it receives. One of the two waveguide arrays is configured to receive a first polarization and the other waveguide array is configured to receive a polarization perpendicular to the first polarization.

Abstract: One or more electrochromic surfaces (11) (formed on rigid or flexible carrier surfaces) are used in various ways with one or more radio frequency energy radiating elements (10) and/or guiding elements (91 and 120) to lend selective reflectivity to achieve greater resultant control over directionality, gain, phase, and/or shape of the radiated energy.

Abstract: In one embodiment, an antenna device includes a scanning reflector, a fixed feeder interacting with the reflector for emitting radar radiation and a detector for detecting reflector passage of at least two different predetermined scanning positions during scanning of the reflector. The antenna device also includes a timer used to determine passage times at the time of reflector passage of the scanning positions. The scanning position of the reflector is predicted at an arbitrary time on the basis of the passage times and a predetermined scanning motion of the reflector. In another embodiment, a method for determining an accurate scanning position for the scanning reflector of the antenna device is disclosed.