Harada Industry Co., Ltd.

Yutaka Imamura

Jun Ishida

Tatsuaki Taniguchi

Kazuo Shigeta

Ryuji Kobayashi

Misao Haneishi

A power feed circuit for a circularly polarized antenna includes a synthesizing-distributing unit and a phase shift unit. The synthesizing-distributing unit distributes input signals to two paths with the same phase and same amplitude. The phase shift unit has two phase shift circuits connected respectively between the two paths distributed by the synthesizing-distributing unit and two feed points of a circularly polarized antenna. The phase shift unit outputs signals whose phase difference is 90° to the two feed points and of the circularly polarized antenna.

Power feed circuit comprising a synthesizing-distributing unit and a phase shifting unit configured for feeding a two point or a four point circularly polarized antenna

An antenna device for a vehicle includes an antenna element having a first main surface, a shielding plate having a second main surface facing the first main surface and wider than the first main surface, the shielding plate being located between the antenna element and a noise source in the vehicle, and an insulating member located between the first main surface and the second main surface to integrate the antenna element and the shielding plate.

Antenna device

A noise reduction device includes: a combiner to shift a phase of one of a first signal propagating through a first propagation path and a second signal propagating through a second propagation path by a predetermined angle and combine the phase-shifted one signal of the first signal and the second signal with the other signal of the first signal and the second signal; and a phase difference absorption circuit having a phase shift characteristic that reduces a difference between a phase difference between two signals each having a lower limit frequency of a band of the broadcast wave and passing through the first propagation path and the second propagation path and a phase difference between two signals each having an upper limit frequency of the band of the broadcast wave and passing through the first propagation path and the second propagation path.

Noise reduction device

A vehicle-body-embedded antenna device includes an antenna element, a circuit board, a coil and a ground bracket. The antenna element of a grounded type has an antenna capacitance adapted to function as a capacitive antenna that supports a first frequency band, and main polarization thereof is polarization substantially parallel to the roof surface. The coil is placed on the circuit board and connected to the power feeding part to which the antenna element is connected for making the antenna element to have an antenna length supporting a second frequency band. The ground bracket is directly grounded to a conductive member of the vehicle body which is provided at an angle different from an angle of the roof surface for improving polarization sensitivity of the antenna element substantially perpendicular to the roof surface.

Vehicle-body-embedded antenna device

A low-profile antenna device is provided for a vehicle. The low-profile antenna device includes a base plate, a circuit board, a base, a top-load element and a coil. The circuit board is disposed on the base plate, in parallel with the base plate. An amplifier circuit is placed on a front surface side of the circuit board, and a ground plate area having a ground plate and an empty area not having a ground plate are provided on a back, surface of the circuit board. The coil is disposed on the front surface side of the circuit board facing the empty area of the circuit board. The coil is disposed in a manner axially parallel with the circuit board, connected between the top-load element and the amplifier circuit, and adjusted to function as a resonance antenna.

Low-profile antenna device

Provided is a low-profile antenna device that allows the height of an antenna to be further reduced. The low-profile antenna device comprises a base section, a helical antenna section, and a top load section. The helical antenna section is wound along an oblique axial direction starting from the base section. The conductive top load section, which is electrically connected to the tip of the helical antenna section, has a top section that is provided on the opposite side to a vehicle, to which the antenna device is fixed, and side sections that are provided on the vehicle side in oblique directions from the top section such that no part of the helical antenna section is placed between the top load section and the vehicle in the direction of a perpendicular line formed therebetween.

A GPS wave antenna apparatus according to the present invention includes a substrate unit having a printed board on which an antenna constituting element including a GPS wave antenna element is mounted integrally as one component, a case having an opening portion at one end, for detachably receiving the substrate unit through the opening portion, and a conductive plate attached to the case so as to block the opening portion and arranged opposite to the GPS wave antenna element at a fixed distance therebetween. The GPS wave antenna element has a thin-film conductive pattern, and the substrate unit includes a low noise amplifier provided on the printed board and a feeder connected to a feeder section of the antenna element through the low noise amplifier.

GPS wave antenna apparatus

A planar antenna comprises an emitting circuit plate having an emitting element made of a micro-strip antenna element, a first dielectric plate, and a feeder circuit plate having a feeder line, in which said feeder line are electromagnetically connected to said emitting element in said emitting circuit plate, and said emitting element is a ring circular emitting element containing a cross bridge conductor in the center thereof.

Growing community of inventors

Tokyo, Japan

Yutaka Imamura