Alps Electric Co., Ltd.

Pacific Industrial Company, Ltd.

Makoto Shigihara

Takashi Sano

Michiya Katou

Shuji Saito

Shigetaka Suzuki

Masahiko Higasa

Makoto Sato

Yusuke Nakamura

Yasuhiro Konno

A valve-integrated transponder includes an air valve and a casing that are integrated with each other, and is disposed within a tire. The air valve is press-fitted to a valve hole in a wheel rim. The casing houses a substrate having a detecting element mounted thereon, an inverse F antenna element, a supporting member, and the like, and is provided with a partition-like reinforcement rib. The reinforcement rib extends along an extension of an axis of the air valve and is loosely fitted in a recessed slot of the supporting member. The antenna element supported by the supporting member has a substantially line symmetrical shape where a pair of radiation conductors symmetrically extend away from each other.

Valve-integrated transponder

A valve-integrated transponder includes an air valve and a casing that are integrated with each other, and is disposed within a tire. The casing houses a substrate having a detecting element mounted thereon, an inverse F antenna element, and a supporting member. The antenna element has a substantially line symmetrical shape where a pair of radiation conductors extend away from each other. A longitudinal direction of the substrate is substantially perpendicular to an axial direction of the air valve, and a lateral direction of the substrate is inclined relative to a well of a wheel rim. The two radiation conductors of the antenna element disposed on the substrate are inclined at a predetermined angle with respect to the substrate, so as to be disposed substantially in parallel to the well that extends at the inner side of the transponder as viewed in the radial direction of the tire.

An antenna apparatus is mounted at a wheel rim as a transponder of a system for monitoring a tire pressure or the like, and attached at an end portion of an air valve. The apparatus includes a circuit board having an electronic circuit portion and a grounding conductor layer, a sheet-metal inverse-F type antenna element, a sheet-metal shield case conducting to the grounding conductor layer to cover the electronic circuit portion, and a resin case for accommodating these components. One side surface extending in a longitudinal direction of a space defined between the circuit board and the radiating conductor of the antenna element faces one of sidewalls of a tire, and the other side surface thereof faces a wall surface of the wheel rim with a distance interposed therebetween, the distance being about one-fourth of a wavelength of a radio wave to be used.

Antenna apparatus for transponder

An antenna device includes a rectangular parallelepiped base member made of a dielectric or magnetic material, a band-shaped first radiation conductor, including a plurality of divided first radiation conductor portions, spirally wound around the base member, a plurality of variable capacitance elements connected between pairs of adjacent portions and disposed on a upper surface of the base member, and a feeding conductor for supplying a tuning voltage to the variable capacitance elements. The first radiation conductor has first radiation conductor parts respectively formed on upper, lower, and rear side surfaces of the base member and first connecting through-holes passing through the upper and lower surfaces are provided in the base member, and the first radiation conductor part on the upper surface and the first radiation conductor part on the lower surface are connected to each another by the first through-holes, and the feeding conductor is disposed on the front surface of the base member.

Antenna device having enhanced reception sensitivity in wide bands

An antenna device includes a prism-shaped or plate-shaped base member made of a dielectric or magnetic material, band-shaped first and second radiation conductors wound around the base member and connected to each other, and a third radiation conductor wound around the base member and connected to the second radiation conductor. The first and second radiation conductors include a plurality of divided portions, and the divided first radiation conductor portions are connected in series by first variable capacitance elements, the divided second radiation conductor portions are connected in series by second variable capacitance elements, and a node between the first and second radiation conductors is used as a feeding end.

The present invention provides an antenna device capable of automatically obtaining excellent receiving sensitivity over a wide band. The antenna device comprises a rod-shaped base made of a dielectric material or a magnetic material; a stripe-shape radiating conductor divided into a plurality of radiating conductors wound around the base; and variable capacitive elements provided to correnspond to the same number of the radiating conductors. The radiating conductors and the variable capacitive elements are alternatively arranged on the base and are connected in series to each other, the radiating conductor having its one end connected to the variable capacitive element serves as an opening side and the variable capacitive element having its one end connected to the radiating conductor serves as a signal feeding side, and capacitance values of the variable capacitive elements increase or decrease in the same direction to be tuned to a predetermined frequency.

Antenna device capable of being tuned in wide band

In a circularly polarized wave antenna, a dielectric member, which is formed of a dielectric material, such as ceramic, is formed in a quadrilateral columnar shape. A through-hole formed in a quadrilateral shape when viewed from above is provided at the center of the dielectric member. Radiation conductors having the same configuration are formed according to, for example, a printing technique, and are disposed on the corresponding four side surfaces of the dielectric member while being tilted at 45&deg;. In the circularly polarized wave antenna, the dielectric member is fixed on a printed circuit board, and the bottom portions of the radiation conductors are soldered to the corresponding portions of the printed circuit board. With this configuration, mutually in-phase power is supplied to the four radiation conductors.

Compact, vibration-resistant circularly polarized wave antenna

The present invention provides a miniaturized circular polarized microstrip antenna that employs a dielectric substrate having a large relative dielectric constant so that a desired resonance frequency and a desired axis ratio are obtained. In a circular polarized wave microstrip antenna,having a nearly square dielectric substrate,with a nearly square patch electrode,formed on one surface thereof, and a ground electrode,formed on almost the whole of another surface thereof, triangular first notches,and,serving as retraction-separation elements are respectively formed 135 and 315 degrees with respect to a direction toward a feeding point,from the center of the patch electrode,, which is defined as 0, and within the first notch,, a first adjustment electrode,extending outwardly from an edge of the patch electrode,is formed. On the other hand, a triangular second notch,is formed 45 degrees with respect to a direction toward the feeding point,from the center of the patch electrode,, which is defined as 0, and within the second notch,, a second adjustment electrode,extending outwardly from an edge of the patch electrode,is formed.

Small-sized circular polarized wave microstrip antenna providing desired resonance frequency and desired axis ratio

An outdoor satellite broadcast receiving converter including a waveguide into which a broadcast electric wave enters and in which the broadcast electric wave travels in an axial direction as a first linearly polarized wave and a second linearly polarized wave. A first probe is disposed at a predetermined position and extends perpendicular to the axial direction into the waveguide for detecting the first linearly polarized wave. A substrate is disposed in the waveguide approximately 1/4 wavelength from the first probe and arranged to extend across an open end of the waveguide. A first shorting terminal for reflecting the first linearly polarized wave is formed on a first side of the substrate, and a second probe for detecting the second linearly polarized wave is formed on an opposing second side of the substrate. A metallic case is connected over the open end of the waveguide such that the substrate is positioned between a closed bottom of the metallic case and the first probe. The closed bottom of the metallic case is disposed about 1/4 wavelength from the substrate, and includes a second shorting terminal for reflecting the second linearly polarized wave.

Growing community of inventors

Fukushima-ken, Japan

Makoto Shigihara