Radio Frequency Systems, Inc.

Celwave

George D Yarsunas

Michael Leonard Brennan

Charles M Powell

Frank Duggan

James R Hendershot

The invention provides a log periodic dipole antenna having a microstrip center feedline and a log periodic hourglass dipole assembly. The microstrip center feedline means responds to an input radio signal for providing a microstrip center feed radio signal. The log periodic hourglass dipole assembly responds to the microstrip feed radio signal, for providing a log periodic hourglass dipole antenna radio signal.

Log periodic dipole antenna having an interior centerfeed microstrip

A circularly polarized antenna has an open reflector box, an array of crossed dipoles, and a single binary feed network. The open reflector box is formed of conductive material, has a ground plate and four side walls defining an opening, and has an input port for receiving an input signal. The single binary feed network is disposed within the open reflector box, is connected to the input port, and has a microstrip transmission line spaced from the ground plate. The microstrip transmission line has conductive bars mounted parallel to the ground plate and spaced therefrom forming an air dielectric low loss microstrip. Each pair of crossed dipoles has a first dipole comprising two downwardly bent radiating elements arranged at an angle with respect to the ground plate, and has a second dipole comprising two straight radiating elements arranged parallel to the ground plate. Each pair of crossed dipoles also has a pair of phase loop connectors and standoffs for respectively connecting an associated downwardly bent radiating element of the first dipole to a corresponding straight radiating element of the second dipole for providing circular polarization in an axial direction. One downwardly bent radiating element is connected to the ground plate, and another downwardly bent radiating element is connected to a respective conductive bar of the single binary feed network, for providing a circularly polarized horizontal beamwidth pattern having a horizontal width determined by the angle of the downwardly bent radiating elements with respect to the ground plate.

Circularly polarized horizontal beamwidth antenna having binary feed

A circularly polarized microcell antenna 10 that requires only a single feed-line to radiate circularly polarized electromagnetic energy therefrom. The antenna 10 comprises a reflector box 14 having a bottom 15 and side walls 17 to which an electrical connector 20 is mounted. The center conductor 24 of the connector 20 is electrically connected to a conductor bar 22 upon which a first dipole assembly is mounted at a designated one-quarter wavelength location. The shell of the connector 20 is electrically connected to the reflector box 14 upon which a second dipole assembly is mounted at a designated one-quarter wavelength location. Each dipole assembly comprises a primary dipole arm 52 and a secondary dipole arm 68 which are electrically connected by a phasing loop that introduces a 90.degree. phase shift between the primary dipole arm 52 and the secondary dipole arm 68. Thus, a single feed-line is capable of feeding both the primary and secondary dipoles so as to allow circularly polarized electromagnetic energy to radiate therefrom.

Circularly polarized microcell antenna

The invention provides a broadband directional antenna having a central reflector plate, a dipole and at least one side reflector panel. The dipole is arranged on the central reflector plate for radiating a radio frequency signal, including a binary feed network having a microstrip transmission line and a colinear array of radiating elements. The side reflector panel is hinged to the central reflector plate for adjusting the horizontal radiation beamwidth of the radio frequency signal.

Variable horizontal beamwidth antenna having hingeable side reflectors

A vehicular multi-band antenna is adapted to receive signals in the AM/FM bands and to receive and transmit signals in a significantly higher frequency band such as that used for cellular telephone. The antenna is provided with a base section fixedly mounted on the vehicle and a removable antenna mast section removably received in the base section.

Connector assembly for fixed triband antenna

A retractable motorized multi-band antenna is adapted to receive signals in the AM/FM bands and to receive and transmit signals in a significantly higher frequency band such as that used for cellular telephone. In order to transfer the coaxial input signal to an output coaxial connector, a slip ring connector is provided. The slip ring connector is impedance matched to the antenna to create low VSWR at RF frequencies.

Retractable motorized multiband antenna

A multi-band antenna is adapted to receive signals in the AM/FM bands and to receive and transmit signals in a significantly higher frequency band such as that used for cellular telephone. An AM/FM band antenna is formed of a tubular rod, and a higher frequency band antenna is formed using a centerfed coaxial dipole mounted on top of and coaxially with the AM/FM antenna. The dipole is fed by a coaxial rod attached to a coaxial cable extending through the AM/FM antenna. A cylindrical choke is disposed about the coaxial rod and is spaced a predetermined distance from the dipole antenna to reduce coupling between the AM/FM antenna and the high-frequency antenna. The choke functions to position the input impedance of the high-frequency antenna at the base of the choke in a manner so that a short matching transformer may be used at the base of the choke for connection to the coaxial cable. In matching the antenna in this manner at the base of the choke, the best possible VSWR characteristics of the antenna are preserved and the radiation pattern of the antenna's main lobe extends horizontally along a horizontal axis.

Growing community of inventors

Vincentown, NJ, United States of America

George D Yarsunas