Abstract: An array antenna includes a feeder element, a parasitic element implemented by a slot line, a variable capacitance element, and a directivity switching unit. The variable capacitance element is loaded in the slot line. The directivity switching unit supplies a control voltage to the variable capacitance element in order to vary the capacitance, and switches directivity of the array antenna.

Abstract: An indoor UHF antenna for a digital television includes a flat structure, which is easy to install and also can be adjusted to different receiving angles according to horizontal polarized waves or vertical polarized waves transmitted by different transmitters. The antenna device includes a circuit board, a main rod antenna, and an auxiliary rod antenna. The main rod antenna is horizontally welded with a signal feeder terminal of the circuit board, and the auxiliary rod antenna is parallel welded with an earth terminal of the circuit board for stabilizing signals. Thereby the whole antenna structure is flat and can be adjusted to any receiving angle easily, so as to match up and be suitable to receive wireless digital television signals of the horizontal polarized waves or vertical polarized waves from different transmitters.

Abstract: An antenna is disclosed. The antenna has a first element including an unbalanced antenna with a feed point, and a second element. The second element has a spaced relationship with the first element, and includes a balanced antenna arranged to be electromagnetically coupled to the first element. Embodiments of the invention exhibit relatively high Pattern Averaged Gain (PAG).

Abstract: The invention provides a dual-access antenna fabricated on a substrate. In one embodiment, the antenna includes a first monopole element, at least one grounded parasitic element located proximate the first monopole element, wherein the separation between the monopole and the grounded parasitic element exhibits a conductive profile which varies the waveguide characteristics of the antenna assembly. The conductive profile is provided by a stepped or angled profile on the or each grounded parasitic element which faces and extends away from first monopole element. This antenna covers the frequency range 900 to 2300 MHz. The antenna includes a secondary grounded element located at an outer position relative to the or an associated grounded parasitic element. In a preferred embodiment, the antenna includes two grounded parasitic elements located on opposite sides of the first monopole element.

Abstract: An antenna apparatus, which can increase capacity in a cellular communication system or Wireless Local Area Network (WLAN), such as an 802.11 network, operates in conjunction with a mobile subscriber unit or client station. At least one antenna element is active and located within multiple passive antenna elements. The passive antenna elements are coupled to selectable impedance components for phase control of re-radiated RF signals. Various techniques for determining the phase of each antenna element are supported to enable the antenna apparatus to direct an antenna beam pattern toward a base station or access point with maximum gain, and, consequently, maximum signal-to-noise ratio. By directionally receiving and transmitting signals, multipath fading is greatly reduced as well as intercell interference.

Abstract: An antenna directivity enhancer to enhance the directivity of an antenna is disclosed. The enhancer has a 3-dimensional structure in a predefined 3-dimensional shape when operating to enhance the directivity of an antenna. The 3-dimensional structure can be flexibly collapsible into 2-dimensional flat surfaces, with at least two of the surfaces not required to have any space between them when the structure is collapsed. The direction where the directivity is enhanced can be changed as desired. The enhancer can include just one reflecting surface, or at least two reflecting surfaces. In yet another embodiment, the enhancer includes a curved surface when the enhancer is in its predefined 3-dimensional shape.

Abstract: Disclosed are systems and methods which provide multi-band antenna elements using multiple radiating branches interconnected with a feed plate, thereby providing a multi-band antenna element having a single feed. Additionally or alternatively, a wide band antenna configuration is provided utilizing multiple radiating branches of a multi-band antenna element of the present invention. Embodiments utilize one or more reflectors, such as to provide directivity and/or radiation pattern shaping, including utilizing one or more radiating branches of a multi-band antenna element as a reflector for another one or more radiating branches of the multi-band antenna.

Abstract: A broadband/multiband circular array antenna is disclosed. One embodiment comprises a circular directional array antenna comprising a driven omnidirectional traveling-wave antenna element coupled to a transceiver via a feed and a plurality of surface-waveguide elements symmetrically positioned about and spaced from the driven omnidirectional traveling-wave antenna element. Each surface-waveguide element receives a control signal configured to selectively alter its waveguide characteristics to electronically direct a beam to/from the array. The array provides a directionally controllable antenna beam with broadband/multiband frequency performance in a low profile design that is both economical and practical to produce and maintain.

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: A microelectromechanical switch (MEMS) beam-steering antenna array is provided. The antenna comprises an active element including a selectively connectable MEMS, and a lattice of beam-forming parasitic elements, each including a selectively connectable MEMS, proximate to the active element. In some aspects, the active element is a dipole radiator having an effective quarter-wavelength odd multiple length at a first plurality of frequencies in response to connecting radiator MEMS. Likewise, the dipole counterpoise has an effective quarter-wavelength odd multiple length at the first plurality of frequencies in response to connecting counterpoise MEMS. Further, each parasitic element has an effective half-wavelength odd multiple length at the first plurality of frequencies in response to connecting their corresponding MEMS. In other aspects, the active element is a monopole and includes a radiator with a radiator MEMS, a counterpoise groundplane, and parasitic elements with MEMSs.

Abstract: A mobile communication handset includes at least one passive antenna element and an active antenna element adjacent to the passive antenna elements protruding from a housing. The active element is coupled to electronic radio communication circuits and the passive antenna elements are coupled to circuit elements that affect the directivity of communication signals coupled to the antenna elements.

Abstract: An adaptive antenna used in a receive only mode with a separate omnidirectional transmit antenna. The arrangement is especially effective for small, handheld wireless devices. The transmit antenna maybe integrated with the receive array by utilizing a horizontally polarized transmit and vertically polarized receiver ray. In other embodiments, the transmit antenna may be physically separate and not integrated with the receive array. In either case there is separate receive and transmit signal port as an interface to radio transceiver equipment. The use of an adaptive antenna in the receive only direction has the potential to increase forward links capacity to levels equal to or greater than reverse link capacity. This allows for a significant increase in the overall number of users that may be active at the same time in a wireless system.

Abstract: According to this invention, there is provided a portable antenna comprising a flexible and durable conductive element fitted into an encasement made from a flexible and durable fabric-like material having a first open end wherefrom one end of the conductive element can be accessed.

Abstract: An antenna having a central active element and a plurality of passive dipoles surrounding the active element is disclosed. The passive dipoles increase the antenna gain by increasing the radiated energy in the azimuth direction. In another embodiment a plurality of parasitic directing elements extend radially outward from the passive dipoles.

Abstract: A broadband/multiband circular array antenna is disclosed. One embodiment comprises a circular directional array antenna comprising a driven omnidirectional traveling-wave antenna element coupled to a transceiver via a feed and a plurality of surface-waveguide elements symmetrically positioned about and spaced from the driven omnidirectional traveling-wave antenna element. Each surface-waveguide element receives a control signal configured to selectively alter its waveguide characteristics to electronically direct a beam to/from the array. The array provides a directionally controllable antenna beam with broadband/multiband frequency performance in a low profile design that is both economical and practical to produce and maintain.

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 cylindrical reflector having a through hole in conformity with the shape of an elemental portion is fitted to the elemental portion in a LAN antenna in which the elemental portion encloses a linear conductor therein and projects from a base table, and further, the reflector is turned to be set at a position at which the directivity is formed in a specific direction. A flat plate or a curved plate forming a reflecting surface of the reflector is arbitrarily set, thus forming a desired radiation pattern of a beam.

Abstract: A reception antenna system for electrical connection to the positive and negative sides of a transmission feedline employed in television and other telecommunications includes a reflector having a conductive surface. The system includes an even group of electrically open-ended radial pairs, having positive and negative ends, of hollow, substantially scalene triangular conductive loops, each loop of each pair being internally symmetric about a radius of the reflector, each pair of the group disposed at an uniform offset from the surface of the reflector, the offset defined by insulative mounting elements. Upon the reflector are elements for electrically connecting one negative end and one of the open-ended loop pairs to an adjacent negative end of another of the loop pairs to thereby define at least two loop pairs, each of which two pairs define a single conductive array which is electrically, but not radiationally, discreet from the reflector.

Abstract: A ground plane beam antenna for transmitting and/or receiving radio frequency (RF) signals, and a method for constructing same, is disclosed. An embodiment of the antenna comprises at least one parasitic reflector element having a first end and a second end, at least one parasitic director element having a first end and a second end, a multi-polarized driven element positioned co-linearly with and between the at least one reflector element and the at least one director element, and an electrically conductive ground plane. The ground plane is electrically connected to the at least one reflector element and the at least one director element at the second ends, and is electrically isolated from the driven element.

Abstract: An adaptive antenna used in a receive only mode with a separate omnidirectional transmit antenna. The arrangement is especially effective for small, handheld wireless devices. The transmit antenna maybe integrated with the receive array by utilizing a horizontally polarized transmit and vertically polarized receiver ray. In other embodiments, the transmit antenna may be physically separate and not integrated with the receive array. In either case there is separate receive and transmit signal port as an interface to radio transceiver equipment. The use of an adaptive antenna in the receive only direction has the potential to increase forward links capacity to levels equal to or greater than reverse link capacity. This allows for a significant increase in the overall number of users that may be active at the same time in a wireless system.

Abstract: An embedded antenna for a mobile terminal, comprising a conductor unit (101), including a PCB, and having a metal-layer-stripped region on its top; an antenna unit (102), including a PCB, being vertically connected to the metal-layer-stripped region on top of said conductor unit, and having a ground pin (204) and a feed pin (205) to be connected to circuits within said mobile terminal; a parasitic unit (103), with one end being attached to said antenna unit, and another end being apart from and in parallel to said antenna unit. The antenna has very small size, is efficiently operative on the frequency bands of GSM900 and DCS1800, and has a moderate gain and a lower SAR.

Abstract: An antenna diversity system includes at least two antennas. Each antenna may be connected via a common connection point to a receiver by a respective switch which presents a low impedance connection between the antenna and receiver in the on state and a substantially reactive load to the antenna in the off state. Selection of appropriate impedances for the off state load enables the antennas to function as an array with a variety of beam patterns depending on the state of the switches. Cycling through a sequence of switch states steers the antenna beam providing improved resistance to fading and multipath effects. Alternatively, the antennas may be connected to a hybrid coupler, which enables two beam patterns to be available simultaneously for signal quality measurement and comparison.

Abstract: A directive antenna operable in multiple frequency bands includes an active antenna element and at least one passive antenna element parasitically coupled to the active antenna element. The passive antenna element(s) have length and spacing substantially optimized to operate at (i) a fundamental frequency associated with the active antenna element and (ii) a higher resonant frequency related to the fundamental frequency. Spatial-harmonic current-distributions of the passive antenna elements are used to create the multiple frequency bands of operation. The directive antenna also includes devices operatively coupled to the passive antenna element(s) to steer an antenna beam formed by applying a signal at the fundamental resonant frequency, higher resonant frequency, or both to the active antenna element to operate in the multiple frequency bands.

Abstract: An active antenna element to transmit and/or receive RF (Radio Frequency) signals is positioned in relation to a backplane that reflects RF signals. One or more passive antenna elements can be disposed on a similar side of the backplane as the active antenna element. Settings of the one or more passive antenna elements are adjusted to produce an input/output beam pattern that varies depending on whether the at least one passive antenna element is reflective or transmissive. Based on this technique, an RF input output beam pattern of an antenna assembly including the backplane, active antenna element and passive antenna elements can be controlled for better reception and transmission of RF signals.

Abstract: A communication system including an antenna array with feed network coupled to communication electronics. In one example, a communication subsystem comprises a plurality of antennas each adapted to receive an information signal and a plurality of orthomode transducers coupled to corresponding ones of the plurality of antennas, each OMT is adapted to provide at a first component signal having a first polarization and a second component signal having a second polarization. The communication subsystem also comprises a feed network that receives the first component signal and the second component signal from each orthomode transducer and provides a first summed component signal at a first feed port and a second summed component signal at a second feed port, and a phase correction device coupled to the first and second feed ports and adapted to phase match the first summed component signal with the second summed component signal.

Abstract: A radiation shielding apparatus for a wireless communication device operable in at least two cellular frequency spectrums includes a multi-band antenna operably associated with an electromagnetic radiation shield that extends along a length of the antenna. The shield partially surrounds the antenna and is disposed between a user of the communication device and the antenna.

Abstract: An antenna system that includes a directional antenna designed to reduce the occurrence of side lobes, thus reducing the possibility of interference with other radio frequencies is disclosed. The directional antenna includes an antenna member and a reflecting tube. The reflective tube is sleeved over the antenna member. The reflective serves to block unwanted radial side lobes. The directional antenna can also include provisions that assist in suspending the antenna member within the reflective tube.

Abstract: An adaptive antenna unit includes feeding antenna elements arranged so as to reduce spatial correlations thereof, parasitic antenna elements, provided with respect to each of the feeding antenna elements and arranged so as to increase mutual coupling between a corresponding one of the feeding antenna elements, variable reactance elements each terminating a corresponding one of the parasitic antenna elements, and a control section. The control section controls reactances of the reactance elements and controls weighting of the reception signals received by the feeding antenna elements, in response to the reception signals.

Abstract: An antenna device for wireless LAN of the present invention includes a base module and an antenna case that receives a built-in antenna therein. A metal reflector plate is held in a base element of the base module. The reflector plate functions to widen the range of directivity of the antenna device and thus ensures stable communication for wireless LAN. The antenna case is pivotable to the base module. The antenna is adjustable to a desired angle according to the requirement, so as to attain communication for wireless LAN.

Abstract: A directive antenna operable in multiple frequency bands includes an active antenna element and at least one passive antenna element parasitically coupled to the active antenna element. The passive antenna element(s) have length and spacing substantially optimized to operate at (i) a fundamental frequency associated with the active antenna element and (ii) a higher resonant frequency related to the fundamental frequency. Spatial-harmonic current-distributions of the passive antenna elements are used to create the multiple frequency bands of operation. The directive antenna also includes devices operatively coupled to the passive antenna element(s) to steer an antenna beam formed by applying a signal at the fundamental resonant frequency, higher resonant frequency, or both to the active antenna element to operate in the multiple frequency bands.

Abstract: The present invention relates to a device for transmitting and/or receiving electromagnetic waves comprising at least one radiating element for radiating a circular polarization of given sense, characterized in that it comprises at least one means dimensioned and positioned with respect to the radiating element in such a way as to radiate, at the frequency of the radiating element, a circular polarization of opposite sense to that of the radiating element so as to compensate for the cross component of the radiating element. The invention applies more particularly to printed antennas operating under circular polarization.

Abstract: Based on a received signal y(t) received by a radiating element of an array antenna including the single radiating element and a plurality of parasitic elements, an adaptive controller calculates and sets a reactance value of a variable reactance element for directing a main beam of the array antenna in a direction of a desired wave and directing nulls in directions of interference waves so that a value of an objective function expressed by only the received signal y(t) becomes either one of the maximum and the minimum by using an iterative numerical solution of a nonlinear programming method.

Abstract: An antenna apparatus having at least one radiating element. A second radiating element is located opposite a first radiating element. Earth is on the side opposite to the first radiating element with respect to the second radiating element thus opposite to the second radiating element. The second radiating element intervenes between the first radiating element and earth. Either the first or the second radiating element employs a feed terminal.

Abstract: An antenna apparatus which can increase capacity in a cellular communication system. The antenna operates in conjunction with a mobile subscriber unit and provides a plurality of antenna elements. At least one active antenna element is active and essentially centrally located within multiple passive antenna elements. The passive antenna elements are coupled to selectable impedance components. Through proper control of the passive antenna elements, the cellular communication system directs an antenna beam pattern toward an antenna tower of a base station to maximize gain, and, consequently, signal-to-noise ratio. Thus, optimum reception is achieved during, for example, an idle mode which receives a pilot signal. The antenna array creates a beamformer for signals to be transmitted from the mobile subscriber unit, and a directional receiving array to more optimally detect and receive signals transmitted from the base station.

Abstract: An adaptive controller for an ESPAR antenna randomly perturbs a bias voltage vector V(n) composed of elements of bias voltage values Vm by a random vector R(n) generated by a random number generator, compares an objective function value J(n) of a cross correlation coefficient for a bias voltage vector V(n) before the perturbation with an objective function value J(n+1) of a cross correlation coefficient for a bias voltage vector V(n+1) after the perturbation, and selects and sets the bias voltage Vm corresponding to that when the cross correlation coefficient increases before and after the perturbation. Then the adaptive controller repeats the random perturbation and setting from the bias voltage of respective varactor diodes. This leads to that it is not necessary to provide a long training sequence signal, and the control process can be executed with learning so that a performance can be improved every iteration for search.

Abstract: An antenna apparatus that includes a beam control system and a beam collimating system having a compound curve antenna structure is provided. The compound curve antenna structure can be two-dimensional or three-dimensional. In one embodiment, the curve is parabolic and the compound curve antenna structure includes first and second parabolic reflector sections that are spaced from each other. A feed array of the beam control system is disposed therebetween at the base ends of the two parabolic reflector sections. When the compound curve antenna structure is three-dimensional, the two parabolic reflector sections are part of a body of revolution. The control system also includes memory storage that stores predetermined data related to controlling activation of each of a plurality of feed elements of the feed array. The predetermined data is based on information obtained using a reference beam with the compound curve antenna structure.

Abstract: A multi-beam antenna system including a parabolic reflector with a parallelogram perimeter, which is illuminated by a plurality of feed elements; so that the parabolic reflector reflects a first beam corresponding to one frequency that illuminates a first parallelogram spot, a second beam corresponding to the same frequency that illuminates a second parallelogram spot, such that the first and second spots are parallelepiped arranged one un-adjacent another of the same frequency are generally un-adjacent.

Abstract: A directive antenna includes plural antenna elements in an antenna assemblage. A feed network connected to the antenna elements includes at least one switch to select a state of one of the antenna elements to be in an active state in response to a control signal. The other antenna elements are in a passive state, electrically coupled to an impedance to be in a reflective mode. The antenna elements in the passive state are electromagnetically coupled to the active antenna element, allowing the antenna assemblage to directionally transmit and receive signals. The directive antenna may further include an assisting switch associated with each antenna element to assist coupling the antenna elements, while in the passive state, to the respective impedances. The antenna assemblage may be circular for a 360° discrete scan in N directions, where N is the number of antenna elements.

Abstract: A linear antenna capable of adjusting directivity and impedance matching comprises: a common dipole in which two cylindrical conductors each having a length of &lgr;/4 of the transmission frequency are provided linearly (thus having a total length of &lgr;/2); a plurality of linear parasitic elements that are provided at positions separated by a distance D2 from the axis of the common dipole so as to surround the common dipole; and a U-shaped parasitic element for realizing impedance matching that is arranged in proximity to one end of the common dipole. Each of the linear parasitic elements are arranged parallel to the common dipole and have a length of one half-wavelength of a desired transmission frequency.

Abstract: The deployable antenna with the tensegrity support structure and mounting frame has improved specific mass, compact stowage volume and high deployment reliability. The reflector is mounted to the tensegrity support structure via the mounting frame which ensures proper deployment of the reflector in the desired antenna operating shape.

Abstract: A foldable antenna includes a plurality of passive elements radially spaced apart from a center active element. The radial passive elements are joined to the active element to create a deformable union. In this way, the surrounding passive elements can be folded toward the midplane of the antenna array to create a relatively compact stored configuration.

Abstract: Dual polarisation antenna having low side lobes, useful in a satellite radiocommunication system.

Abstract: A feed probe (1), a semicylindrical sub-reflector (2) forming a primary radiator together with the feed probe (1), and a main reflector (3) arranged such that mirror surfaces of said main reflector (3) and the sub-reflector face across the feed probe (1) are all disposed on a ground plate (a recfector face) (4). The main reflector (3) has a predetermined focal point or focal line on which the feed probe (1) is located, and is mounted on the ground plate (4) at a predetermined installation angle &thgr;. A converter (500) for converting linearly and circularly polarized waves is provided on the mirror surface of the main reflector (3).

Abstract: Systems and devices for mechanically rotating the polarisation of a signal emanating from or being received by an antenna system. The rotation of the polarisation is achieved by mechanically rotating the feed using a non-metallic drive cord or belt connected to a motor which is displaced outside or behind the radiating aperture. For a linear array of multiple antenna elements, each feed for each antenna element is rotated simultaneously and by an equal amount through the use of a drive system common to all the feeds. The drive system is coupled to each feed and to a drive motor. When the motor is activated, the drive system simultaneously rotates each feed by a given amount. By rotating the feed, the polarisation of the signal is correspondingly rotated and compensation for polarisation loss is provided.

Abstract: An antenna that has an alignment configuration for aligning the antenna with a satellite. In one embodiment, the antenna includes an antenna reflector that has a centerline and a front surface and a rear surface. A reference plane is defined on the rear surface that is perpendicular to the centerline of the reflector. The reference plane is used in connection with alignment devices for orienting the antenna reflector in desired azimuth, elevation, and skew orientations.

Abstract: The present invention provides a low-cost, steerable antenna formed with a dielectric medium separating a pair of conductive plates and a centrally located signal feed. Switches selectively interconnect the conductive plates through the dielectric medium in patterns, which determine the direction of operation of the antenna. The directionality of the antenna may be fixed or rapidly changed, depending upon the application.

Abstract: A communication antenna (10) having a driven element (16) extending between a feed point (13) and an attachment point (15) to a top loaded element in which the driven element (16) is longer than the shortest distance (P) between the feed point (13) and the attachment point (15), the driven element (16) being configured to follow a meandering path between the feed point (13) and the attachment point (15). The driven element (16) is at least in part in the form of straight sections joined to give a zigzag configuration (16). Alternatively the driven element (16) is at least in part in the form of curved sections.

Abstract: A directional antenna designed to reduce the occurrence of side lobes, thus reducing the possibility of interference with other radio frequencies is disclosed. The directional antenna includes an antenna member and a reflecting tube. The reflective tube is sleeved over the antenna member. The reflective serves to block unwanted radial side lobes. The directional antenna can also include provisions that assist in suspending the antenna member within the reflective tube. A method for making the directional antenna is also described.

Abstract: A full-wave loop antenna assembly having unique mechanical stability and electromagnetic characteristics is disclosed. The antenna assembly is suitable for use in the High frequency and Very high frequency portions of the electromagnetic spectrum and is capable of supporting multiple driven and parasitic elements in a variety of configurations for multi-band operation. The assembly includes an upper load-bearing boom and a lower boom which may be load bearing, between which at least a part of the weight loads created by the driven and parasitic elements may be distributed. The assembly may also include a parasitic element, tuned as a reflector, which is considerably longer than other parasitic reflectors which are used with antennas of this type, thereby providing the desired directional characteristics over a wider range of frequencies than are obtained by other antennas of its type.

Abstract: The antenna apparatus of the present invention places antenna element 302 that transmits or receives electromagnetic waves on basic plate 301, places parasitic antenna elements 303 to 306 on basic plate 301 evenly spaced concentrically centered on antenna element 302, places switch elements 307 to 310 and capacitances 311 to 314 in parallel between one end of each of antenna elements 303 to 306 and said basic plate and disconnects one of switch elements 307 to 310 and connects all the others. In this way, the present invention provides a small and high-gain antenna apparatus with directivity switching capability.