Abstract: An antenna device includes a ground plate which is a flat plate-shaped conductor member, an opposing conductive plate which is a flat plate-shaped conductor member installed at a predetermined distance from the ground plate and is electrically connected to a power supply line, and a plurality of short-circuit pins for electrically connecting the opposing conductive plate and the ground plate. One end of a plurality of short-circuit pins extends to a conductive plate plane, which is a plane including the opposing conductive plate, and the other end of the plurality of short-circuit pins extends to the ground plate plane, which is a plane including the ground plate. One or more of the plurality of short-circuit pins connect the opposing conductive plate and the ground plate.

Abstract: An antenna device includes a ground plate made of a flat conductor member, and an opposing conductive plate, which is a flat conductor member placed at a predetermined distance from the ground plate and electrically connected to a power supply line, a short-circuit portion provided in a central region of the opposing conductive plate for electrically connecting the opposing conductive plate and the ground plate. An operating frequency is a frequency at which an inductance of the short-circuit portion and the capacitance formed by the ground plate and the opposing conductive plate resonate in parallel. The short-circuit portion has a perimeter part that is short-circuited with the opposing conductive plate. A circuit is arranged in an area surrounded by a part where a short-circuit portion is short-circuited on the opposing conductive plate.

Abstract: A positioning system executes wireless communication with a portable terminal by adopting a radio wave of 1 GHz or higher to determine a position of the portable terminal relative to a vehicle. The positioning system includes a vehicle exterior communication device and a positioning device. The positioning device determines whether the portable terminal exists at an exterior operating area being a region outside a vehicle compartment within a predetermined operating distance from the vehicle, based on a reception status of the wireless signal received by the vehicle exterior communication device from the portable terminal in a first mode of the vehicle exterior communication device, and determines whether the portable terminal exists inside the vehicle compartment, based on the reception status of the wireless signal received by the vehicle exterior communication device from the portable terminal in a second mode of the vehicle exterior communication device.

Abstract: A security system includes a portable terminal, a communication device communicating with the portable terminal, and a determination unit determining validity of the portable terminal. Phase data acquired from distance measuring radio wave is used to determine validity of communication between the portable terminal and the communication device. The received phase data of the distance measuring radio wave varies according to the distance from a transmission source. When the communication device and the portable terminal are fixed, and the communication device and the portable terminal have transmitted and received distance measuring radio waves having the same specific frequency, vehicle acquisition phase data and terminal acquisition phase data are the same. The determination unit determines, by using this two types of phase data, the validity of communication between the communication device and the portable terminal is determined.

Abstract: A distance estimation device includes a mobile terminal transmitting a radio wave and an in-vehicle device. The in-vehicle device includes a direction determination unit having a receiver, a distance measurement unit, and a correction unit. The receiver receives the radio wave and is arranged on a side of the vehicle. The direction determination unit determines a direction from which the radio wave comes based on a signal strength of the received radio wave. The distance measurement unit receives the radio wave and measures a distance from an installation position of the distance measurement unit to the mobile terminal based on information other than a signal strength of the received radio wave. The correction unit corrects the measured distance to be a distance from an edge of the vehicle to the mobile terminal based on the determined direction and the installation position.

Abstract: An antenna mounting system includes an antenna device and a conductive base plate. The antenna device includes a ground plate, an opposing conductive plate, and a short-circuit pin. The short-circuit pin is positioned to cause a radio wave radiated from the antenna device in a direction perpendicular to the ground plate such that radio wave: has a polarization component that oscillates in a direction parallel to a main plane of polarization of a radio wave radiated from the conductive base plate in the direction perpendicular to the ground plate; and is shifted in phase from the radio wave radiated from the conductive base plate by a phase difference within a range from 90 degrees to 270 degrees.

Abstract: An antenna device includes a ground plate and an antenna element. The ground plate is a conductor member with a flat rectangular shape. The antenna element is a conductor member having a feed point electrically connected to a feeder line. A length of the ground plate in a predetermined direction is shorter than a target wavelength that is a wavelength of a radio wave to be transmitted or received. The ground plate is connected to a grounding cable at a connection position on the ground plate. The connection position is shifted from an edge of the ground plate by an odd multiple of ¼ of the target wavelength.

Abstract: A position estimation system includes: a position estimation unit configured to estimate a position of a mobile terminal based on a reception status of signals that are transmitted from the mobile terminal and received by a plurality of communication devices; a scene determination unit configured to determine, based on information from a sensor mounted in a vehicle, whether a current status is a simultaneous operation scene in which both a millimeter wave radar and a radar vicinity device are operable simultaneously; and an operating mode changing unit configured to change an operating mode of at least one of the millimeter wave radar, the communication device, or the position estimation unit in response to the scene determination unit determining that the current status is the simultaneous operation scene.

Abstract: An antenna device includes a ground plate which is a flat plate-shaped conductor member, an opposing conductive plate which is a flat plate-shaped conductor member installed at a predetermined distance from the ground plate and is electrically connected to a power supply line, and a plurality of short-circuit pins for electrically connecting the opposing conductive plate and the ground plate. One end of a plurality of short-circuit pins extends to a conductive plate plane, which is a plane including the opposing conductive plate, and the other end of the plurality of short-circuit pins extends to the ground plate plane, which is a plane including the ground plate. One or more of the plurality of short-circuit pins connect the opposing conductive plate and the ground plate.

Abstract: A security system includes a portable terminal, a communication device communicating with the portable terminal, and a determination unit determining validity of the portable terminal. Phase data acquired from distance measuring radio wave is used to determine validity of communication between the portable terminal and the communication device. The received phase data of the distance measuring radio wave varies according to the distance from a transmission source. When the communication device and the portable terminal are fixed, and the communication device and the portable terminal have transmitted and received distance measuring radio waves having the same specific frequency, vehicle acquisition phase data and terminal acquisition phase data are the same. The determination unit determines, by using this two types of phase data, the validity of communication between the communication device and the portable terminal is determined.

Abstract: An antenna device includes a ground plate that is a conductive member having a plate shape, a patch section that is a conductive member having a plate shape and is disposed in parallel with the ground plate with a predetermined interval so as to face the ground plate, a plurality of first short-circuit vias each having an axial center disposed on a circumference of a via arrangement circle located in a center portion of the patch section and each having a first end connected with the patch section and a second end connected with the ground plate, and at least one second short-circuit via having an axial center disposed at a position different from the circumference of the via arrangement circle and having a first end connected with the patch section and a second end connected with the ground plate.

Abstract: A distance data between the portable device and the vehicle-side transmission and reception device is acquired. A movement speed of the portable device is calculated based on a change between a current distance data and a previous distance data. A position estimation distance for estimating the position of the portable device with respect to the vehicle is updated when the movement speed is less than a first speed. The position estimation distance is not updated when the movement speed is equal to or larger than the first speed. The position of the portable device is estimated according to the position estimation distance.

Abstract: A positioning system executes wireless communication with a portable terminal by adopting a radio wave of 1 GHz or higher to determine a position of the portable terminal relative to a vehicle. The positioning system includes a vehicle exterior communication device and a positioning device. The vehicle exterior communication device is disposed at an outer surface portion at least one of a side surface portion or a rear side surface portion of the vehicle, and includes an antenna receiving a wireless signal transmitted from the portable terminal. The positioning device determines whether or not the portable terminal exists at an exterior operating area being a region outside a vehicle compartment within a predetermined operating distance from the vehicle, based on a reception status of the wireless signal received by the vehicle exterior communication device from the portable terminal. The antenna radiates a main polarized wave and a cross-polarized wave.

Abstract: A positioning system executes wireless communication with a portable terminal by adopting a radio wave of 1 GHz or higher to determine a position of the portable terminal relative to a vehicle. The positioning system includes a vehicle exterior communication device and a positioning device. The positioning device determines whether the portable terminal exists at an exterior operating area being a region outside a vehicle compartment within a predetermined operating distance from the vehicle, based on a reception status of the wireless signal received by the vehicle exterior communication device from the portable terminal in a first mode of the vehicle exterior communication device, and determines whether the portable terminal exists inside the vehicle compartment, based on the reception status of the wireless signal received by the vehicle exterior communication device from the portable terminal in a second mode of the vehicle exterior communication device.

Abstract: An antenna device includes a ground plate that is a conductive member having a plate shape, a patch section that is a conductive member having a plate shape and is disposed in parallel with the ground plate with a predetermined interval so as to face the ground plate, a plurality of first short-circuit vias each having an axial center disposed on a circumference of a via arrangement circle located in a center portion of the patch section and each having a first end connected with the patch section and a second end connected with the ground plate, and at least one second short-circuit via having an axial center disposed at a position different from the circumference of the via arrangement circle and having a first end connected with the patch section and a second end connected with the ground plate.