Abstract: A distance measurement apparatus of an embodiment includes a first device provided in a vehicle and a second device provided in a key-fob, and calculates a distance between the vehicle and the key-fob based on carrier phase detection. In at least one of the first device and the second device, transmission powers at which a plurality of first distance measurement signals are respectively transmitted when the key-fob is inside the vehicle are set to be lower than transmission powers at which a plurality of first distance measurement signals are respectively transmitted when the key-fob is outside the vehicle.

Abstract: A distance measuring device includes a calculating section that calculates, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first transceiver that transmits three or more first carrier signals and receives three or more second carrier signals using an output of a first reference signal source. The second device includes a second transceiver that transmits the three or more second carrier signals and receives the three or more first carrier signals using an output of a second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals and corrects the calculated distance based on information concerning an amplitude ratio of the first carrier signals received by the second transceiver.

Abstract: A ranging apparatus of an embodiment is a ranging apparatus adopting communication type ranging by a phase detection scheme. The ranging apparatus including: a transmitting circuit configured to be able to transmit by a plurality of channels used for data communication and configured to transmit a transmission signal obtained by modulating transmission data; and a control circuit configured to control the transmission circuit to cause a plurality of continuous waves having mutually different frequencies to be generated in a same channel as continuous waves used for ranging by the phase detection scheme.

Abstract: A phase correcting device includes a local oscillator configured to give a local oscillation signal to a device configured to detect a phase of an inputted signal, a first phase detector configured to detect a phase of the local oscillation signal to output the phase of the local oscillation signal, a reference phase device configured to generate a quasi-reference phase corresponding to a reference phase of the local oscillation signal at a time of an initial setting of the local oscillator to output the quasi-reference phase, based on a reference clock, a second phase detector configured to detect a fluctuation amount of a phase of the local oscillator, based on the phase detected by the first phase detector and the quasi-reference phase, and a correction circuit configured to correct the phase of the inputted signal by using a detection result of the second phase detector.

Abstract: A distance measurement apparatus of an embodiment includes a first device provided in a vehicle and a second device provided in a key-fob, and calculates a distance between the vehicle and the key-fob based on carrier phase detection. In at least one of the first device and the second device, transmission powers at which a plurality of first distance measurement signals are respectively transmitted when the key-fob is inside the vehicle are set to be lower than transmission powers at which a plurality of first distance measurement signals are respectively transmitted when the key-fob is outside the vehicle.

Abstract: A distance measuring device includes a calculating section that calculates, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first transceiver that transmits three or more first carrier signals and receives three or more second carrier signals using an output of a first reference signal source. The second device includes a second transceiver that transmits the three or more second carrier signals and receives the three or more first carrier signals using an output of a second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals and corrects the calculated distance based on information concerning an amplitude ratio of the first carrier signals received by the second transceiver.

Abstract: A distance measuring device includes a calculating section configured to calculate, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first reference signal source and a first transceiver configured to transmit two or more first carrier signals and receives two or more second carrier signals using an output of the first reference signal source. The second device includes a second reference signal source configured to operate independently from the first reference signal source and a second transceiver configured to transmit the second carrier signals and receives the first carrier signals using an output of the second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals.

Abstract: A distance measuring device includes a calculating section configured to calculate, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first reference signal source and a first transceiver configured to transmit two or more first carrier signals and receives two or more second carrier signals using an output of the first reference signal source. The second device includes a second reference signal source configured to operate independently from the first reference signal source and a second transceiver configured to transmit the second carrier signals and receives the first carrier signals using an output of the second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals.

Abstract: According to an embodiment, a first device includes: a first transceiver configured to transmit two or more first carrier signals using an output of a first reference signal source and to receive two or more second carrier signals; and a calculation unit, and a second device includes: a second transceiver configured to transmit the two or more second carrier signals using an output of a second reference signal source that operates independently of the first reference signal source and to receive the two or more first carrier signals. A frequency group of the two or more first carrier signals and a frequency group of the two or more second carrier signals are identical or substantially identical to each other, and the calculation unit calculates the distance between the first device and the second device based on a phase detection result obtained by receiving the first and second carrier signals.

Abstract: A distance measuring apparatus according to an embodiment includes, a filter section configured to perform band limitation on a transmission signal and output the transmission signal, and to perform band limitation on a reception signal from an antenna section and output the reception signal, a distance measuring section configured to perform a distance measurement computation based on the transmission signal and the reception signal, and to obtain a delay of a signal passing through the filter section and perform calibration of the distance measurement computation, a signal interruption section configured to interrupt transmission of a signal between the filter section and the antenna section, and a control section configured to control the signal interruption section to interrupt the transmission of the signal during a period of the calibration.

Abstract: A first device includes: a first reference signal source; a first transmitting/receiving unit which transmits two or more first carrier signals and receives two or more second carrier signals using an output of the first reference signal source; and a calculating unit. A second device includes: a second reference signal source configured to be operated independently from the first reference signal source; and a second transmitting/receiving unit configured to transmit two or more second carrier signals and receive two or more first carrier signals using an output of the second reference signal source. A frequency group of two or more first carrier signals and a frequency group of two or more second carrier signals differ from each other. The calculating unit calculates a distance between the first device and the second device based on a phase detection result obtained by receiving the first and second carrier signals.

Abstract: A distance-measuring system of an embodiment configured to calculate a distance between a first device and a second device based on transmission and reception between the first device and the second device includes a communication section configured to communicate with a first frequency band and/or with a second frequency band different from the first frequency band, a determination section configured to determine whether the first device is located within a predetermined range of the second device, and a control section configured to control, when a determination result of the determination section shows that the first device is not within the predetermined range, to perform a distance-measuring operation is performed with the first frequency band, and when a determination result of the determination section shows that the first device is within the predetermined range, to perform a distance-measuring operation with the second frequency band.

Abstract: A distance measuring device includes a calculating section that calculates, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first transceiver that transmits three or more first carrier signals and receives three or more second carrier signals using an output of a first reference signal source. The second device includes a second transceiver that transmits the three or more second carrier signals and receives the three or more first carrier signals using an output of a second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals and corrects the calculated distance based on information concerning an amplitude ratio of the first carrier signals received by the second transceiver.

Abstract: A distance measuring device includes a calculating section that calculates, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first transceiver that transmits three or more first carrier signals and receives three or more second carrier signals using an output of a first reference signal source. The second device includes a second transceiver that transmits the three or more second carrier signals and receives the three or more first carrier signals using an output of a second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals and corrects the calculated distance based on information concerning an amplitude ratio of the first carrier signals received by the second transceiver.

Abstract: A distance measurement system for transmitting and receiving a distance measurement signal including a phase detection signal between first and second devices and calculating a distance between the devices based on a phase detection result of the received phase detection signal includes a modulation circuit configured to generate the distance measurement signal including a modulated signal obtained by modulating an identification signal, a transmission circuit configured to transmit the distance measurement signal, a reception circuit configured to receive the distance measurement signal, a demodulation circuit configured to demodulate the modulated signal in the received distance measurement signal, and a control circuit configured to judge a restored state of the identification signal obtained from a demodulation result of the demodulation circuit.

Abstract: A distance measuring device includes a calculating section configured to calculate, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first reference signal source and a first transceiver configured to transmit two or more first carrier signals and receives two or more second carrier signals using an output of the first reference signal source. The second device includes a second reference signal source configured to operate independently from the first reference signal source and a second transceiver configured to transmit the second carrier signals and receives the first carrier signals using an output of the second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals.

Abstract: A distance measuring device includes a calculating section that calculates, based on phase information acquired by a first device and a second device, at least one of which is movable, a distance between the first device and the second device. The first device includes a first transceiver that transmits three or more first carrier signals and receives three or more second carrier signals using an output of a first reference signal source. The second device includes a second transceiver that transmits the three or more second carrier signals and receives the three or more first carrier signals using an output of a second reference signal source. The calculating section calculates the distance based on a phase detection result obtained by reception of the first and second carrier signals and corrects the calculated distance based on information concerning an amplitude ratio of the first carrier signals received by the second transceiver.

Abstract: A band-pass filter circuit includes a low-pass filter, a high-pass filter including an integrator, and a controller. The controller is configured to increase a cut-off frequency of the high-pass filter for a predetermined period of time, when changing a gain of the low-pass filter. Further, the controller is configured to increase a cut-off frequency of the low-pass filter or decrease a Q value of the low-pass filter for the predetermined period of time.

Abstract: There is provided a reference voltage generating apparatus including: a reference voltage source, a voltage retaining circuit, a switch and a controller. The reference voltage source generates a reference voltage. The voltage retaining circuit includes a first element circuit and a second element circuit, and the voltage retaining circuit outputs a voltage of a connection node between a first terminal of the first element circuit and a second terminal of the second element circuit. The switch is connected between the connection node and the reference voltage source. The controller controls the reference voltage source and the switch. The first element circuit includes at least a resistance component and the first element circuit is supplied with a first voltage at a third terminal and the second element circuit includes a resistance component and a capacity component and the second element circuit is supplied with a second voltage at a fourth terminal.

Abstract: There is provided a reference voltage generating apparatus including: a reference voltage source, a voltage retaining circuit, a switch and a controller. The reference voltage source generates a reference voltage. The voltage retaining circuit includes a first element circuit and a second element circuit, and the voltage retaining circuit outputs a voltage of a connection node between a first terminal of the first element circuit and a second terminal of the second element circuit. The switch is connected between the connection node and the reference voltage source. The controller controls the reference voltage source and the switch. The first element circuit includes at least a resistance component and the first element circuit is supplied with a first voltage at a third terminal and the second element circuit includes a resistance component and a capacity component and the second element circuit is supplied with a second voltage at a fourth terminal.