Abstract: A varactor based phase shifter that increases phase shift range using a lower characteristic impedance between quadrature ports than is used at its input/output ports. The circuit makes use of a four port coupler arrangement that imbeds a quarter wave impedance transformation between the input port and the quadrature ports as well as between the quadrature ports and the output port. The characteristic impedance across the quadrature ports is therefore less than the characteristic impedance across the input and output ports. In one implementation, reducing a characteristic input/output impedance of 50 to a 20 ohm quadrature port impedance results in a phase shift range increase of more than 50%.

Abstract: A method for reworking a ball grid array (BGA) of solder balls is provided including one or more defective solder balls on an electronic component workpiece using a single-ball extractor/placer apparatus having a heatable capillary tube pickup head optionally augmented with vacuum suction. A defective solder ball is identified, extracted by the pickup head and disposed of. A nondefective solder ball is picked up by the pickup head, positioned on the vacated attachment site, and thermally softened for attachment to the workpiece. Flux may be first applied to the replacement solder ball or to the vacated attachment site. The extractor/placer apparatus may be automated to locate, extract and replace defective balls for completion of a fully operable BGA.

Abstract: A varactor based phase shifter that increases phase shift range using a lower characteristic impedance between quadrature ports than is used at its input/output ports. The circuit makes use of a four port coupler arrangement that imbeds a quarter wave impedance transformation between the input port and the quadrature ports as well as between the quadrature ports and the output port. The characteristic impedance across the quadrature ports is therefore less than the characteristic impedance across the input and output ports. In one implementation, reducing a characteristic input/output impedance of 50 to a 20 ohm quadrature port impedance results in a phase shift range increase of more than 50%.

Abstract: An antenna assembly includes at least two active or main radiating omni-directional antenna elements arranged with at least one beam control or passive antenna element used as a reflector. The beam control antenna element(s) may have multiple reactance elements that can electrically terminate it to adjust the input or output beam pattern(s) produced by the combination of the active antenna elements and the beam control antenna element(s). More specifically, the beam control antenna element(s) may be coupled to different terminating reactances to change beam characteristics, such as the directivity and angular beamwidth. Processing may be employed to select which terminating reactance to use. Consequently, the radiator pattern of the antenna can be more easily directed towards a specific target receiver/transmitter, reduce signal-to-noise interference levels, and/or increase gain by using Radio Frequency (RF), Intermediate Frequency (IF), or baseband processing.

Abstract: An antenna array that uses at least two passive antennas and one active antenna disposed above a ground plane, but electrically isolated from the ground plane, and a respective resonant strip positioned beneath each passive antenna. The passive antenna elements are positioned about the active element, and each of the at least two passive antenna elements is individually set to a reflective or a transmissive mode to change the characteristics of an input/output beam pattern of the antenna apparatus.

Abstract: An access point antenna for a wireless local area network (WLAN) includes a combiner network with a feed point, a ground plane adjacent the combiner network, and a dielectric substrate adjacent the ground plane. Conductive paths are on the dielectric substrate and are coupled to the feed point. Active antenna elements extend from the dielectric substrate. Each active antenna element is coupled to a respective conductive path and is equally spaced from a common area on the dielectric substrate. A passive director antenna element extends from the dielectric substrate and is coupled to the ground plane adjacent the common area.

Abstract: A directive antenna having plural antenna elements is arranged in a parasitic antenna array. Frequency selective components are connected to an active antenna element. Weighting structures are connected to passive antenna elements positioned substantially equidistant from the active antenna element. The active and passive antenna elements are connected by a space-fed power distribution system to produce independently steerable beams having spectrally separated signals.

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: An antenna array formed on a deformable dielectric material or substrate includes a center element and plurality of radial elements extending from a center hub. In the operative mode, the radial elements are folded upwardly into an approximately vertical position, with the center element at the center of the hub and the radial elements circumferentially surrounding the center element. In one embodiment the center element serves an active element of the antenna array and the radial elements are controllable in a directive or reflective state to effect a directive beam pattern from the antenna array. When not in use, the antenna elements are deformed into a plane and can therefore be integrated into a housing for compact storage. In a phased array embodiment, the center element is absent and the plurality of radial elements, are controllable to steer the antenna beam.

Abstract: A folded monopole antenna that supports lower and upper frequency bands may be used in CDMA, WLAN, or other wireless communications systems. The folded monopole antenna may be located in a handset next to a vertical ground plane. The folded monopole antenna may be folded at least twice and connected to the ground plane through a reactance. The dimensions of different sections of the folded monopole antenna define lower and upper frequency band characteristics, and an offset location of an input feed affects the bandwidth of the frequency bands. The reactance between the antenna and ground plane can be selected to fine tune the frequency bands. Various input feeds, including a co-planar waveguide, may be employed. Dynamically adjustable reactances may be used in the input feed and ground line for adapting the antenna to various environments.

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 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 directional antenna having a number, N, of outlying monopole antenna elements. These monopole elements are formed as a first upper conductive segment on a portion of a dielectric substrate. The array also includes the same number, N, of image elements. The image elements are formed as a second set of lower conductive segments on the same substrate as the upper conductive segments. The image elements, generally having the same length and shape as the monopole elements, are connected to a ground reference potential. To complete the array, an active antenna element is also disposed on the same substrate, adjacent to at least one of the monopole elements. In a preferred arrangement, the passive monopole elements and corresponding image elements are selectively connected to operate to in either a reflective or directive mode, such as via a switchable coupling circuit that selectively changes the impedances connected between them.

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: A directive antenna having plural antenna elements is arranged in a parasitic antenna array. Frequency selective components are connected to a first subset of the antenna elements. Weighting structures are connected to a second subset of the antenna elements. The first and second subsets of antenna elements may be connected by a space-fed power distribution system to produce independently steerable beams having spectrally separated signals.

Abstract: An antenna array formed on a deformable dielectric material or substrate includes a center element and plurality of radial elements extending from a center hub. In the operative mode, the radial elements are folded upwardly into an approximately vertical position, with the center element at the center of the hub and the radial elements circumferentially surrounding the center element. In one embodiment the center element serves an active element of the antenna array and the radial elements are controllable in a directive or reflective state to effect a directive beam pattern from the antenna array. When not in use, the antenna elements are deformed into a plane and can therefore be integrated into a housing for compact storage. In a phased array embodiment, the center element is absent and the plurality of radial elements, are controllable to steer the antenna beam.

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 antenna array that uses at least two passive antennas and one active antenna disposed above a ground plane, but electrically isolated from the ground plane, and a respective resonant strip positioned beneath each passive antenna. The passive antenna elements are positioned about the active element, and each of the at least two passive antenna elements is individually set to a reflective or a transmissive mode to change the characteristics of an input/output beam pattern of the antenna apparatus.

Abstract: A directional antenna having a number, N, of outlying monopole antenna elements. These monopole elements are formed as a first upper conductive segment on a portion of a dielectric substrate. The array also includes the same number, N, of image elements. The image elements are formed as a second set of lower conductive segments on the same substrate as the upper conductive segments. The image elements, generally having the same length and shape as the monopole elements, are connected to a ground reference potential. To complete the array, an active antenna element is also disposed on the same substrate, adjacent to at least one of the monopole elements. In a preferred arrangement, the passive monopole elements and corresponding image elements are selectively connected to operate to in either a reflective or directive mode, such as via a switchable coupling circuit that selectively changes the impedances connected between them.