An after-market antenna for a vehicle includes an elongated body having a top end, a bottom end, and at least one peripheral side. The bottom end terminates with an axial bore extending partially through the body and adapted to receive an antenna wire within. The axial bore includes threads at the bottom end of the body that extend upward at least partially through the axial bore for receiving a conductive threaded shaft that projects out of the axial bore and that is adapted for screwing into a threaded antenna aperture of the vehicle. A first groove is formed around the body and has a back wall that is substantially circular in cross-section except for two opposing parallel sides adapted for contacting two opposing sides of a wrench that has a thickness that is smaller than a width of the first groove.

A dual-band antenna module includes a substrate, a dual-band omnidirectional antenna, a low-frequency reflection module and a high-frequency reflection module. The dual-band omnidirectional antenna is disposed perpendicular to the substrate and is used for resonating to generate a first radio-frequency signal with a first frequency and a second radio-frequency signal with a second frequency. The low-frequency reflection module includes three low-frequency reflection units used for reflecting the first radio-frequency signal with the first frequency according to different low-frequency directional control signals. The high-frequency reflection module includes three high-frequency reflection units used for reflecting the second radio-frequency signal with the second frequency according to different high-frequency directional control signals. The low-frequency reflection units of the low-frequency reflection module and the high-frequency reflection units of the high-frequency reflection module are disposed on the substrate and are disposed around the dual-band omnidirectional antenna.

A dual-band antenna module includes a substrate, a dual-band omnidirectional antenna, a low-frequency reflection module and a high-frequency reflection module. The dual-band omnidirectional antenna is disposed perpendicular to the substrate and is used for resonating to generate a first radio-frequency signal with a first frequency and a second radio-frequency signal with a second frequency. The low-frequency reflection module includes three low-frequency reflection units used for reflecting the first radio-frequency signal with the first frequency according to different low-frequency directional control signals. The high-frequency reflection module includes three high-frequency reflection units used for reflecting the second radio-frequency signal with the second frequency according to different high-frequency directional control signals. The low-frequency reflection units of the low-frequency reflection module and the high-frequency reflection units of the high-frequency reflection module are disposed on the substrate and are disposed around the dual-band omnidirectional antenna.

An apparatus is provided to mitigate the adverse effects of mutual coupling. The apparatus includes a ground plane and first and second active radiators spaced from the ground plane. The first and second active radiators are configured to the electrically coupled to at least one of a receiver, a transmitter or a transceiver. The antenna also includes a grounded radiator electrically coupled to the ground plane and positioned between the first and second active radiators. The ground plane defines a non-conductive slot positioned between the first and second active radiators and bounded by the ground plane.

A radio frequency antenna with a two-piece sealing ferrule. The antenna includes a center antenna and an outer tube surrounding the center antenna. A mounting nut surrounds and is slidable relative to the outer tube. An outer ferrule surrounds and is slidable relative to the outer tube. An inner ferrule that is separate from the outer ferrule surrounds and is fixed to the outer tube. A mating nut is secured to the mounting nut. The threading of the mounting nut and the mating nut together results in the wedging between the inner and outer ferrules which results in the exertion of a first compressive force by the inner ferrule against the outer tube for sealing the inner ferrule and the outer tube and the exertion of a second compressive force of the inner ferrule against the mating nut for sealing the inner ferrule and the mating nut.

An antenna device includes: an antenna element for vertically polarized waves, having a first straight line portion of which one end serves as a power feeding point, and an annular portion of which one end is connected to another end of the first straight line portion; and a first dielectric cover covering the antenna element from outside. An antenna device includes: an antenna element for vertically polarized waves, having a first straight line portion of which one end serves as a power feeding point, and an annular portion of which one end is connected to another end of the first straight line portion; and a second dielectric cover covering the first straight line portion and the annular portion from outside.

An antenna device includes: an antenna element for vertically polarized waves, having a first straight line portion of which one end serves as a power feeding point, and an annular portion of which one end is connected to another end of the first straight line portion; and a first dielectric cover covering the antenna element from outside. An antenna device includes: an antenna element for vertically polarized waves, having a first straight line portion of which one end serves as a power feeding point, and an annular portion of which one end is connected to another end of the first straight line portion; and a second dielectric cover covering the first straight line portion and the annular portion from outside.

Provided are examples of removable circularly polarized antenna fitment and methods of fabrication. In one aspect, a fitment comprises a plurality of conductive elements spaced radially around a central point contained with a housing. The elements may have an included angle of between 8 and 71 degrees from horizontal. The plurality of conducting elements may be straight, bent, or curved and may be comprised of between 3 and 12 conductors. The fitment may contain a housing which is removable from a linear antenna.

Provided is a directional monopole array antenna using a hybrid ground plane in which a plurality of monopole antennas are connected in a form of an array, wherein the monopole antennas includes: a ground plane designed to be divided into a PMC (perfect magnetic conductor) and a PEC (perfect electric conductor) such that a surface current induced in the PEC flows in a direction; and an antenna device vertically disposed in the ground plane.

Provided is a directional monopole array antenna using a hybrid ground plane in which a plurality of monopole antennas are connected in a form of an array, wherein the monopole antennas includes: a ground plane designed to be divided into a PMC (perfect magnetic conductor) and a PEC (perfect electric conductor) such that a surface current induced in the PEC flows in a direction; and an antenna device vertically disposed in the ground plane.