Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: An antenna for transmitting and receiving radio frequency energy. The antenna comprises a conductive radiator comprising a first and a second conductive region for providing a first and a second current path length. A feed conductor and a ground conductor operate as meanderline (or slow wave) elements to provide an electrical length longer than a physical length.

Abstract: A radio frequency transmitting and receiving apparatus comprising an antenna further comprising a plurality of antenna segments. Each segment exhibits a different electrical length and certain of the segments are capacitively coupled to establish a resonant frequency for each segment. In one embodiment, the certain segments comprise a plurality of concentric arcuate conductive elements connected to a signal terminal and a ground plane.

Abstract: An antenna for transmitting and receiving radio frequency energy. The antenna comprises a conductive top plate formed in the shape of a spiral. In one embodiment a sidewall meanderline extends from an edge of the top plate in the direction of a ground plane. A shorting meanderline connects the top plate and the ground plane. A first region of the top plate overlies the ground plane. A second region of the top plate extends beyond the ground plane. Tuning is provided by adjusting the length and other dimensions of the meanderlines.

Abstract: An antenna providing circular polarization for received and transmitted signals. The antenna comprises a vertical conductive surfaces oriented to form a closed structure and horizontal conductive surfaces forming a top face of the closed structure. Connection of selected vertical panels to a feed and ground, causes current flow in the vertical and horizontal surfaces that results in a circular polarized signal.

Abstract: A planar antenna comprising a spiral conductive surface comprising an inner spiral segment and an outer spiral segment. A shorting leg for connection to a ground plane and a feed leg responsive to the antenna signal (in the transmit and the receive modes) extend downwardly from the plane of the spiral segments. Performance characteristics of the antenna are responsive to the configuration and spacing of the spiral segments and the distance between the antenna and the ground plane.

Abstract: An antenna structure for use in a communications device for reducing a user's SAR exposure. In addition to the conventional antenna elements, e.g., a radiating element and a ground plane, the antenna structure of the present invention comprises a conductive element for directing radio frequency energy emitted by the radiating element away from the user, thereby reducing the user's SAR exposure. The conductive element can be disposed on an interior or an exterior surface of a case enclosing the communications device.

Abstract: A radio frequency identification tag attached to an object and comprising an antenna and an integrated circuit for providing object information to a separate reader. The antenna further comprises a pair of meanderline transmission lines each terminated at a first end for conductive connection to the integrated circuit. A shorting bar connected between the pair of meanderline transmission lines at the first ends is operative to match an antenna impedance with an integrated circuit impedance.

Abstract: An antenna for a folder type communications handset. The handset comprises first and second enclosures pivotably joined to permit rotation of one enclosure relative to the other enclosure. The antenna is disposed over a ground plane formed in a printed circuit board in the first enclosure. The second enclosure also comprises a ground plane. A feed terminal and a ground terminal of the antenna are disposed to limit field coupling between the feed terminal and the ground plane in the second enclosure. The feed and the ground terminals are each connected to corresponding terminals on the printed circuit board by meanderline conductors.

Abstract: An antenna incorporating slow wave structures. The antenna comprises at least two conductive serpentine structures disposed on a dielectric substrate and further comprising an oppositely disposed conductive top plate electrically connected to the conductive serpentine structures and farther electromagnetically connected thereto. In one embodiment the antenna further comprises a ground plane below the dielectric substrate.

Abstract: An antenna for transmitting and receiving radio frequency energy. The antenna comprises a conductive top plate formed in the shape of a spiral. In one embodiment a sidewall meanderline extends from an edge of the top plate in the direction of a ground plane. A shorting meanderline connects the top plate and the ground plane. A first region of the top plate overlies the ground plane. A second region of the top plate extends beyond the ground plane. Tuning is provided by adjusting the length and other dimensions of the meanderlines.

Abstract: An antenna providing circular polarization for received and transmitted signals. The antenna comprises a vertical conductive surfaces oriented to form a closed structure and horizontal conductive surfaces forming a top face of the closed structure.

Abstract: An antenna incorporating slow wave structures. The antenna comprises at least two conductive serpentine structures disposed on a dielectric substrate and further comprising an oppositely disposed conductive top plate electrically connected to the conductive serpentine structures and farther electromagnetically connected thereto. In one embodiment the antenna further comprises a ground plane below the dielectric substrate.

Abstract: A planar antenna comprising a spiral conductive surface comprising an inner spiral segment and an outer spiral segment. A shorting leg for connection to a ground plane and a feed leg responsive to the antenna signal (in the transmit and the receive modes) extend downwardly from the plane of the spiral segments. Performance characteristics of the antenna are responsive to the configuration and spacing of the spiral segments and the distance between the antenna and the ground plane.

Abstract: There is disclosed a meanderline-loaded antenna comprising a ground plane, a non-driven element affixed thereto, a driven or receiving element affixed thereto and a horizontal element between the driven and the non-driven elements. The non-driven and the driven elements comprise meanderline-loaded couplers that are oriented parallel to the ground plane and the horizontal element so as to present a low-profile meanderline-loaded antenna.

Abstract: There is disclosed a meanderline loaded antenna comprising a ground plane, two vertical elements orthogonally affixed thereto, and a horizontal element between the two vertical elements. A meanderline coupler interconnects the horizontal element, at each of its ends, to the vertical elements. The antenna further includes an additional radiating element extending from the horizontal element in approximately planer relationship therewith. Additionally, the antenna includes a tuning element extending from the horizontal element and forming an acute angle with the adjacent vertical element.

Abstract: There is disclosed a meanderline loaded antenna comprising a ground plane, a plurality of vertical elements orthogonally affixed thereto, a driven vertical element affixed thereto and a horizontal element between the vertical elements. All but one of the plurality of vertical elements have an effective electrical length that is a quarter wavelength of the antenna operating frequency. Thus, these vertical elements represent an open and do not effect the antenna performance characteristics. One of the plurality of vertical elements will be operative and therefore the antenna length comprises the length of the operative element, the length of the driven element, and the length of the top plate therebetween.

Abstract: There is disclosed a meanderline-loaded antenna comprising a ground plane, a non-driven element affixed thereto, a driven or receiving element affixed thereto and a horizontal element between the driven and the non-driven elements. The non-driven and the driven elements comprise meanderline-loaded couplers that are oriented parallel to the ground plane and the horizontal element so as to present a low-profile meanderline-loaded antenna.