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.

There are provided methods and systems configured to perform calibration of antenna array systems, for example during production, avoiding the use of external setups or external measurements. The method comprising: (i) measuring the delay of a dedicated calibration transmission line for each SUT, for example during production, using internal built-in system capabilities; (ii) comparing the measured delay to a known delay of an identical transmission line of a reference system; (iii) computing, based on this comparison, compensation values with respect to the reference system of delay (or phase), for all transmission lines of the SUT; (iv) calibrating the SUT using the computed compensation values for all transmission lines of the SUT.

A system for estimating a substance level in a storage unit is disclosed. In one embodiment, the system includes a cable and a control device. The control device sense pulses down the cable and based on the time of reflected pulses determines the level of substance in the storage unit.

A system simulates a moving target for a radar system under test. The system includes a Doppler simulation circuit (DSC), coupled to an input, to apply a frequency shift to RF pulses received on an RF signal to simulate speed. A signal attenuator coupled to the DSC is to simulate signal attenuation due to propagation loss of the RF pulses in atmosphere. A pulse detection circuit is to detect time of receipt of the RF pulses, including a first time of receipt of a falling edge of a first RF pulse. An I/O controller updates a value of the frequency shift for the DSC and of the signal attenuation for the signal attenuator during a time period between the first RF pulse and one of a second RF pulse or a second time at which the second RF pulse should have been received in case of a missing pulse.

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.

A radar time synchronization system according to an example embodiment of the present disclosure include a transmitter radar, a receiver radar, and a quantum interferometer device communicatively coupled to the transmitter radar and the receiver radar. The quantum interferometer device includes a quantum entanglement source operable to transmit a first entangled photon to the transmitter radar and a second entangled photon to the receiver radar. The quantum interferometer device further includes a quantum entanglement detector operable to receive the first entangled photon from the transmitter radar and the second entangled photon from the receiver radar. The quantum entanglement detector further operable to detect a quantum interference effect associated with the first entangled photon and the second entangled photon. The quantum interferometer device synchronizes a first time associated with the transmitter radar and a second time associated with the receiver radar based at least in part on the quantum interference effect.

A radar target simulation system for simulating at least one moving radar target is disclosed. The radar target simulation system includes an analog to digital converter and at least one digital processing channel. The digital processing channel includes a delay circuit or unit, a resampling circuit or unit and a frequency shifting circuit or unit. Moreover, a method for operating a radar target simulation system is disclosed.

Disclosed is a self-calibration method and apparatus for an array antenna system. According to an embodiment of the present disclosure, a correction method of an array antenna system includes: deriving, at a first time, a correction factor R.sub.i,j for a path connecting an i-th (i is an integer equal to or greater than one and equal to or less than m) transmission antenna and a j-th (j is an integer equal to or greater than one and equal to or less than n) reception antenna; deriving, at a second time, a calibration factor {circumflex over (Q)}.sub.i,j for the path connecting the i-th transmission antenna and the j-th reception antenna; and performing, based on the {circumflex over (Q)}.sub.i,j, calibration on the path connecting the i-th transmission antenna and the j-th reception antenna.

A distance measuring device according to an embodiment includes a filter, a first switching circuit, an impedance adjustable circuit, a second switching circuit, a third switching circuit, and a fourth switching circuit. The filter restricts a signal for distance measurement transmitted from the transmission circuit and a signal for distance measurement received by an antenna within a desired frequency band. The impedance adjustable circuit is adjusted to have a higher impedance than an impedance of the antenna. The second switching circuit switches conduction and non-conduction between the impedance adjustable circuit and the transmission circuit. The third switching circuit switches conduction and non-conduction between the impedance adjustable circuit and the reception circuit. The fourth switching circuit switches conduction and non-conduction between the impedance adjustable circuit and the second switching circuit and between the impedance adjustable circuit and the third switching circuit.

The application discloses a method for verifying the accuracy of a guided-wave radar measuring device used in process automation. The method includes sending measuring radar waves to a built-in verification circuit of a known and verified length and performing time-of-flight analysis on the measuring radar wave reflected by the built-in verification circuit. The application also discloses a guided-wave radar device having a built-in verification circuit.