An electronic device may be provided with wireless circuitry that includes first, second, and third antennas used to determine the position and orientation of the electronic device relative to external equipment. The antennas may include patch elements on respective substrates mounted to a flexible printed circuit. Each substrate may include fences of conductive vias that are coupled to ground and that laterally surround the corresponding patch element. Control circuitry may identify phase differences between the first and second antennas and between the second and third antennas and may identify an angle of arrival of received ultra-wideband signals using the phase differences. The control circuitry may compare the phase differences to a set of predetermined surfaces of phase differences to identify environmental loading conditions for the antenna. The control circuitry may correct the angle of arrival using offsets identified based on the environmental loading conditions.

An angle of arrival system can be self-calibrating. The angle of arrival system can continuously estimate imperfections caused by the analog RF components and dynamically apply corrections based on these estimates. As a result, an angle of arrival system can employ inexpensive components, will not require factory calibration, but can still perform geolocation with high precision.

Example techniques relate to playback based on acoustic signals in a system including a first network device and a second network device. A first network device may detect a presence of a user using a camera and/or infrared sensors. The first network device sends, in response to detecting the presence of the user, a particular signal via the first network interface. The second network device receives data corresponding to the particular signal and plays back an audio output corresponding to the particular signal.

A direction detection device for detecting a received-wave arrival direction of a received wave, and includes: antennas for receiving the received wave; an intensity difference imparting unit that imparts intensity differences different depending on the received-wave arrival direction to intensities of the received wave; a storage unit that stores an intensity difference table in which the intensity difference between two of the antennas is associated with the received-wave arrival direction, for each combination of any two of the antennas; a detector that detects the intensity difference between the two antennas of the received wave; an extractor that extracts, from the intensity difference table, received-wave arrival directions corresponding to the intensity difference detected by the detector, for each combination; and a comparator that compares the received-wave arrival directions extracted by the extractor between the combinations of the antennas to acquire a matched received-wave arrival direction as a detection result.

An ultra-wideband (UWB) communication system comprising a transmitter and a receiver having two antennas. An UWB signal transmitted by the transmitter is received at each of the antennas. By comparing the carrier phases of the received signals, the phase difference can be determined. From this phase difference and the known distance, d, between the antennas, the Cartesian (x, y) location of the transmitter relative to the receiver can be directly determined.

Example techniques relate to playback based on acoustic signals in a system including a first network device and a second network device. A first network device may detect a presence of a user using a camera and/or infrared sensors. The first network device sends, in response to detecting the presence of the user, a particular signal via the first network interface. The second network device receives data corresponding to the particular signal and plays back an audio output corresponding to the particular signal.

A system and method of the disclosure relates to satellite tracking. The system may comprise a tracking receiver that includes a first analog-to-digital (A/D) converter coupled between a sum input and a digital signal processor (DSP), a second A/D converter coupled between a difference input and the DSP, and a calibration output coupled to the sum input and coupled to the difference input. The first A/D converter may convert an signal received at the sum input into a sum digital signal, and provide the sum digital signal to the DSP. The second A/D converter may convert an signal received at the difference input into a difference digital signal, and provide the difference digital signal to the DSP. The tracking receiver may generate an calibration signal and provide the calibration signal through the calibration output.

An ultra-wideband (UWB) communication system comprising a transmitter and a receiver having two antennas. An UWB signal transmitted by the transmitter is received at each of the antennas. By comparing the carrier phases of the received signals, the phase difference can be determined. From this phase difference and the known distance, d, between the antennas, the Cartesian (x,y) location of the transmitter relative to the receiver can be directly determined.

A test method in operational phase includes three distinct steps, a first step using the replies of the transponder to the interrogations in the Mode S transmitted in operational mode by the secondary radar to perform the measurement of the power of the transponder, and the measurement of the average rate of reply to the interrogations in Mode S transmitted by the radar intended for it; a second step which performs the measurement of the sensitivity of the transponder and a third step which carries out the test of its maximum rate of reply. The second step and the third step are carried out by modifying the operating parameters of the radar so that the additional interrogations required for the measurement can be performed, during the time interval following the last operational interrogation during which the aircraft remains located within the main Sum channel lobe of the antenna of the radar.

This invention is present an iterative method for joint antenna array calibration and direction of arrival estimation using millimeter-wave (mm-Wave) radar. The calibration compensates for array coupling, phase, and gain errors and does not require any training data. This method is well suited for applications where multiple antenna elements are packaged in a chip and where offline calibration is either expensive or is not possible. This invention is also effective when the array coupling is a function of direction of arriving waves from the object. It is also applicable to any two-dimensional array shape. Real experiment results demonstrate the viability of the algorithm using real data collected from a four-element array.