Abstract: A vehicle wireless device is used in a state being attached to an attachment surface of a vehicle. A circuit board includes a circuit that transmits or receives a radio wave at a predetermined target frequency. An antenna includes a board parallel portion parallel to the circuit board to receive a horizontally polarized wave having a vibration direction of an electric field parallel to the circuit board. A case accommodates the circuit board and the antenna. The circuit board faces the attachment surface when the vehicle wireless device is attached to the attachment surface. The circuit board may have a board region overlapping the board parallel portion without a conductor plate being provided in the board region. An inner space of the case may have a case region extending by ?/4 downward from the board parallel portion without a conductor plate being provided in the case region.

Abstract: A vehicle unit installable and usable in a vehicle, includes, at least one vehicle antenna transmitting and receiving a high-frequency signal, which is a signal carried on a high-frequency radio wave, and the vehicle antenna includes, a vertically polarized wave antenna capable of transmitting and receiving a polarized wave orthogonal to a target surface, which is a metal surface at a predetermined part of the vehicle, and first and second horizontally polarized wave antennas each capable of transmitting and receiving polarized waves that are horizontal to the target surface and mutually orthogonally polarized.

Abstract: An antenna device includes: a first antenna having a directional gain at a low elevation angle higher than the directional gain at a high elevation angle; a second antenna having the directional gain at the high elevation angle higher than the first antenna, transmitting and receiving a radio wave having a vibration direction of an electric field intersecting with a radio wave transmitted and received by the first antenna; and a third antenna having the directional gain at the high elevation angle higher than the first antenna, and transmitting and receiving a radio wave having a vibration direction of an electric field intersecting with the radio wave transmitted and received by the second antenna.

Abstract: A vehicular position estimation system estimates a portable terminal position with respect to a vehicle. Each of three or more in-vehicle communication devices is attached at a different position of the vehicle. Each of the multiple in-vehicle communication devices generates distance information indicating a distance from the in-vehicle communication device to the portable terminal. The vehicular position estimation system includes a position coordinate calculation portion that calculates a position coordinate of the portable terminal, and an area inside-outside determination portion that determines whether the portable terminal is inside the system actuation area.

Abstract: A vehicular position estimation system determines a portable terminal position by causing multiple in-vehicle communication devices placed at different positions on a vehicle to wirelessly communicate with a potable terminal, and includes: a distance index value acquisition portion that acquires a distance index value indicating a distance between the multiple in-vehicle communication devices; a normal range storage portion that stores data indicating a normal range of the distance index value; and a communication device diagnosis portion that determines whether the in-vehicle communication device is normal. When the distance index value between a diagnosis target device and at least one different device is in a normal range, the communication device diagnosis portion determines that a failure does not occur in the diagnosis target device.

Abstract: A ringing suppressor circuit is connected to a differential signal transmission line that includes a high potential signal line and low potential signal line pair for transmitting high and low level differential signals, and includes a ringing suppressor and a stopper. When the differential signal changes to a high level, the ringing suppressor suppresses ringing by lowering the impedance between the signal lines by turning ON of a switching element. When a differential signal voltage drops below a voltage lowering determination voltage, the stopper stops the impedance lowering function of the ringing suppressor by turning OFF another switching element.

Abstract: An electronic control unit coupled to a transmission line of a differential signal includes: a first suppression circuit suppressing a ringing effect and decreasing an impedance of the line for a first time interval when a level of the differential signal changes; a second suppression circuits suppressing a ringing effect and decreasing the impedance of the line for a second time interval when the level of the differential signal changes; and a switching unit isolating the second suppression circuit from the line when the operation power source energizes the electronic control unit, and connecting the second suppression circuit to the line when the operation power source does not energize the electronic control unit.

Abstract: An electronic control unit coupled to a transmission line of a differential signal includes: a first suppression circuit suppressing a ringing effect and decreasing an impedance of the line for a first time interval when a level of the differential signal changes; a second suppression circuits suppressing a ringing effect and decreasing the impedance of the line for a second time interval when the level of the differential signal changes; and a switching unit isolating the second suppression circuit from the line when the operation power source energizes the electronic control unit, and connecting the second suppression circuit to the line when the operation power source does not energize the electronic control unit.

Abstract: A relay device for data between communication cables having a signal line in full duplex communication, includes: communication units connected to the communication cables; and a main controller executing a relay process of the data. Each communication unit includes: an input/output unit of an analog signal; an analog/digital converter converting the analog signal into a digital signal; a generator generating another digital signal based on another analog signal input to another communication unit; and an echo canceller calculating a filter coefficient based on the other digital signal and the digital signal, and executing a cancellation process of removing a component derived from the other digital signal from the digital signal according to the filter coefficient. The communication unit or the main control unit includes a sign determination unit determining based on a time change of the filter coefficient whether a sign of disconnection exists in the signal line.

Abstract: A ringing suppressor circuit is connected to a differential signal transmission line that includes a high potential signal line and low potential signal line pair for transmitting high and low level differential signals, and includes a ringing suppressor and a stopper. When the differential signal changes to a high level, the ringing suppressor suppresses ringing by lowering the impedance between the signal lines by turning ON of a switching element. When a differential signal voltage drops below a voltage lowering determination voltage, the stopper stops the impedance lowering function of the ringing suppressor by turning OFF another switching element.

Abstract: A relay device for data between communication cables having a signal line in full duplex communication, includes: communication units connected to the communication cables; and a main controller executing a relay process of the data. Each communication unit includes: an input/output unit of an analog signal; an analog/digital converter converting the analog signal into a digital signal; a generator generating another digital signal based on another analog signal input to another communication unit; and an echo canceller calculating a filter coefficient based on the other digital signal and the digital signal, and executing a cancellation process of removing a component derived from the other digital signal from the digital signal according to the filter coefficient. The communication unit or the main control unit includes a sign determination unit determining based on a time change of the filter coefficient whether a sign of disconnection exists in the signal line.

Abstract: A network control device includes a communicator performing communications via a transmission line at a preset transmission speed in a wake-up mode, a low frequency attenuator attenuating a low frequency component in a transmission signal having a low transmission speed that is lower than the preset transmission speed at a position between the transmission line and the communicator to receive and transmit the transmission signal to and from the communicator, and a wake-up controller receiving and transmitting a wake-up signal for transitioning from a sleep mode to the wake-up mode, at a transmission line side position of the low frequency attenuator, where the wake-up signal at a low frequency band is subject to attenuation by the low frequency attenuator, for a selective wake-up of a network node via the transmission line for network communications.

Abstract: A relay device includes a communication signal relay unit for relaying a communication signal and a wake-up signal relay unit for relaying, by bypassing the communication signal relay unit, a wake-up signal that is transmitted using a frequency band which is lower than a communication frequency band used in transmitting the communication signal. The communication signal relay unit includes a low frequency wave attenuation unit for attenuating a signal with a frequency band lower than the communication frequency band. The wake-up signal relay unit includes a wake-up signal filter unit for passing through a signal with a frequency band lower than the communication frequency band.

Abstract: A relay device includes a communication signal relay unit for relaying a communication signal and a wake-up signal relay unit for relaying, by bypassing the communication signal relay unit, a wake-up signal that is transmitted using a frequency band which is lower than a communication frequency band used in transmitting the communication signal. The communication signal relay unit includes a low frequency wave attenuation unit for attenuating a signal with a frequency band lower than the communication frequency band. The wake-up signal relay unit includes a wake-up signal filter unit for passing through a signal with a frequency band lower than the communication frequency band.

Abstract: A network control device includes a communicator performing communications via a transmission line at a preset transmission speed in a wake-up mode, a low frequency attenuator attenuating a low frequency component in a transmission signal having a low transmission speed that is lower than the preset transmission speed at a position between the transmission line and the communicator to receive and transmit the transmission signal to and from the communicator, and a wake-up controller receiving and transmitting a wake-up signal for transitioning from a sleep mode to the wake-up mode, at a transmission line side position of the low frequency attenuator, where the wake-up signal at a low frequency band is subject to attenuation by the low frequency attenuator, for a selective wake-up of a network node via the transmission line for network communications.