Abstract: In one embodiment, a first antenna element has a substantially vertical axis. An array of second antenna elements is configured to radiate or receive an aggregate radially polarized electromagnetic signal component. The array defines a substantially horizontal plane that is generally orthogonal to the substantially vertical axis of the first antenna element. The aggregate radially polarized electromagnetic signal is derived from radially polarized electromagnetic signal components associated with corresponding ones of the second antenna elements. The aggregate radially polarized electromagnetic signal is derived from radially polarized electromagnetic signal components associated with corresponding ones of the second antenna elements.

Abstract: In one embodiment, a first antenna element has a substantially vertical axis. An array of second antenna elements is configured to radiate or receive an aggregate radially polarized electromagnetic signal component. The array defines a substantially horizontal plane that is generally orthogonal to the substantially vertical axis of the first antenna element. The aggregate radially polarized electromagnetic signal is derived from radially polarized electromagnetic signal components associated with corresponding ones of the second antenna elements. The aggregate radially polarized electromagnetic signal is derived from radially polarized electromagnetic signal components associated with corresponding ones of the second antenna elements.

Abstract: In accordance with one embodiment, a supplemental device for an antenna system comprises a ring that provides a generally horizontal annular ground plane, where the ring has an interior circumference. A substantially annular wall rises or extends from the ring at or near the interior circumference. A set of radial members extends radially upward from the ring, the radial members spaced apart from each other.

Abstract: In accordance with one embodiment, a supplemental device for an antenna system comprises a ring that provides a generally horizontal annular ground plane, where the ring has an interior circumference. A substantially annular wall rises or extends from the ring at or near the interior circumference. A set of radial members extends radially upward from the ring, the radial members spaced apart from each other.

Abstract: An antenna comprises notched semi-elliptical radiators. Each of the radiators has a first substantially planar surface. A ground plane has a second substantially planar surface that is generally parallel to the first substantially planar surfaces of the radiators by a generally uniform spacing. The ground plane has a central axis. Feeding members are adapted for conveying an electromagnetic signal to or from each radiator. Each of the feeding members is spaced radially outward from the central axis of the ground plane. A grounded member is coupled to each radiator and spaced apart, radially outward from the feeding spacer.

Abstract: An antenna comprises notched semi-elliptical radiators. Each of the radiators has a first substantially planar surface. A ground plane has a second substantially planar surface that is generally parallel to the first substantially planar surfaces of the radiators by a generally uniform spacing. The ground plane has a central axis. Feeding members are adapted for conveying an electromagnetic signal to or from each radiator. Each of the feeding members is spaced radially outward from the central axis of the ground plane. A grounded member is coupled to each radiator and spaced apart, radially outward from the feeding spacer.

Abstract: An antenna includes a first antenna element and a second antenna element, wherein the first antenna element and the second antenna element are both configured in a hook shape. The antenna also includes a first impedance matching circuit coupled to the first antenna element, wherein the first impedance matching circuit includes a first plurality of filters and a second impedance matching circuit coupled to the second antenna element, wherein the second impedance matching circuit includes a second plurality of filters.

Abstract: An antenna includes a first antenna element and a second antenna element. The first antenna element and the second antenna element are both configured to receive signals in a first band of frequencies and in a second band of frequencies. Frequencies in the second band of frequencies are greater than frequencies in the first band of frequencies. A first impedance matching circuit, coupled to the first antenna element, includes a first plurality of filters having a first shared component. A second impedance matching circuit, coupled to the second antenna element, includes a second plurality of filters having a second shared component. A feed network circuit is coupled to the first impedance matching circuit and to the second impedance matching circuit and has a combined output corresponding to the signals received by the first antenna element and a second antenna element.

Abstract: An antenna includes a first antenna element and a second antenna element, wherein the first antenna element and the second antenna element are both configured in a hook shape. The antenna also includes a first impedance matching circuit coupled to the first antenna element, wherein the first impedance matching circuit includes a first plurality of filters and a second impedance matching circuit coupled to the second antenna element, wherein the second impedance matching circuit includes a second plurality of filters.

Abstract: An antenna includes a first antenna element and a second antenna element. The first antenna element and the second antenna element are both configured to receive signals in a first band of frequencies and in a second band of frequencies. Frequencies in the second band of frequencies are greater than frequencies in the first band of frequencies. A first impedance matching circuit, coupled to the first antenna element, includes a first plurality of filters having a first shared component. A second impedance matching circuit, coupled to the second antenna element, includes a second plurality of filters having a second shared component. A feed network circuit is coupled to the first impedance matching circuit and to the second impedance matching circuit and has a combined output corresponding to the signals received by the first antenna element and a second antenna element.

Abstract: An antenna includes a first antenna element and a second antenna element. The first antenna element and the second antenna element are configured to transmit and receive signals in a first band of frequencies and in a second band of frequencies. A first pair of delay lines is coupled to the first antenna element and a second pair of delay lines coupled to the second antenna element. A first delay line in the first pair of delay lines and the second pair of delay lines is configured to phase shift electrical signals coupled to the first antenna element and the second antenna element such that a first impedance of the antenna is approximately equal in the first band of frequencies and the second band of frequencies. A second delay line in the first pair of delay lines and the second pair of delay lines is configured to convert the first impedance to a second impedance.

Abstract: The present invention is an improved position tracking system utilizing at least three cw transmitting stations generally symmetrically disposed about an area of interest, and also including a mobile receiving station receiving the transmitted signals, converting the received signals to a common frequency, and comparing the phase difference between the converted signals to produce and output signal indicating the location of the mobile station relative to any desired point or points in the area of interest.