A direction-finding antenna includes at least a first set of radiating elements configured to radiate at least a first wavelength (λ.sub.1) and a second set of radiating elements configured to radiate at a second wavelength (λ.sub.2) that is shorter than the first wavelength (λ.sub.1). The first set of radiating elements defines a first circle having a first radius. The second set of radiating elements defines a second circle having a second radius that is smaller than the first radius of the first circle. The direction-finding antenna further includes a transmission line-based multiplexer configured to selectively couple the first set of radiating elements or the second set of radiating elements to a radio frequency (RF) feed line, or a plurality of switches configured to selectively couple selected radiating elements of the first set of radiating elements or the second set of radiating elements to the RF feed line.

Presented herein are embodiments of signal detection and location finding directed to a “Signature Detector and Direction Finder” (SDDF) add-on module. The SDDF is an add-on module to any Signal Detection System (SDS) that detects, locates, and/or tracks any type(s) of Radio Frequency (RF) signals. Even though the presented embodiments can be used with any RF signal type, the preferred targets are Uncrewed Aerial Vehicles (UAV) or drones, and their controllers. A goal of the SDDF add-on module is to recognize the reported signal of interest and identify its direction. The machine-learning feature enables the system (i.e. SDDF add-on module with SDS) to be deployable in various environments with flexibility in choosing the antenna type(s). The Signature Detector component of the SDDF add-on module uniquely filters drone/controller signals, hence, more accurate direction estimation of the detected signal by SDDF add-on module.

The disclosed invention provides a distributed directional aperture (DDA) system that is installed in a vertical lift aircraft that comprises a fuselage and a rotor system including rotary wings rotatably coupled to the fuselage. The DDA system provides capability to receive and/or transmit signals in one or more frequency bands, and provides communications, signals intelligence (SIGNINT), positional sensing, jamming, and offensive cyber on the vertical lift aircraft. The DDA system of the vertical lift aircraft includes a sensor and emitter array subsystem that includes a plurality of sensors and emitters distributed in the rotary wings, a beamformer subsystem that processes the sensor signals and emitter signals, and a telemetry subsystem that conveys signals between the sensor and emitter array subsystem and the beamformer subsystem.

Provided are a device and a method for estimating an angle of arrival (AoA) and an angle of departure (AoD) in a communication system having 1-bit quantization.

Systems and methods for detecting radio frequency (“RF”) signals and corresponding origination locations are disclosed. An RF sensor device includes a software-defined radio and an antenna pair for receiving RF signals. Furthermore the RF sensor device may include a processing unit for processing/analyzing the RF signals, or the processing unit may be remote. The system calculates a phase difference between an RF signal received at two separate antennas of an antenna pair. The phase difference, the distance between the antennas, and the frequency of the RF signal are used for determining the origination direction of the RF signal. In various embodiments, the origination direction may indicate the location of a UAV controller or base station. The software-defined radio may include more than one antenna pair, connected to multiplexers, for efficiently scanning different frequencies by alternating active antenna pairs. Moreover, the system may execute packet-based processing on the RF signal data.

A method for signal processing includes receiving via first and second antennas (34) respective first and second input signals in response to an output signal that is transmitted from a wireless transmitter (27, 28, 30) and encodes a predefined sequence of symbols. A temporal correlation function is computed over the first and second input signals with respect to one or more of the symbols in the predefined sequence so as to identify respective first and second correlation peaks and extract respective first and second carrier phases of the first and second input signals at the first and second correlation peaks. A phase difference between the first and second signals is measured based on a difference between the first and second carrier phases extracted at the first and second correlation peaks. Based on the measured phase difference, an angle of arrival of the output signal from the wireless transmitter is estimated. There is additionally provided, in accordance with an embodiment of the invention, a method for location finding, which includes receiving radio signals transmitted between a plurality of fixed transceivers having multiple antennas at different, respective first locations and a mobile transceiver at a second location. A respective phase difference is detected between the received radio signals that are associated with each of the multiple antennas of each of the fixed transceivers. Multiple loci are computed, corresponding respectively to respective angles between each of the fixed transceivers and the mobile transceiver based on the respective phase differences. Location coordinates of the mobile transceiver are found based on the angles and the transmit locations of the transmitters by identifying an intersection of the loci as the second location of the mobile transceiver.

An example wireless audio electronic device includes a first antenna, a communication circuit, and a processor. The processor may be configured to receive a positioning signal from an external electronic device through the first antenna so as to obtain first positioning information; obtain, from a different audio device located in a case together with the wireless audio electronic device, second positioning information for the positioning signal received by the different wireless audio electronic device; determine an angle of arrival of the positioning signal based on the first positioning information, the second positioning information, and the distance between the wireless audio electronic device and the different wireless audio electronic device; and transmit a response signal including information of the angle of arrival to the external electronic device.

There is provided mechanisms for estimating angle of arrival of a radio signal in a radio communications network. A method is performed by a receiving radio transceiver device. The method comprises obtaining measurements of the radio signal as received in two receive beams covering a given angular sector. The two receive beams are created by analog beamforming in an antenna array. The receive beams have different complex beam patterns and at any angle within the given angular sector at most one of the complex beam patterns has gain below a threshold. The method comprises estimating the angle of arrival of the radio signal by comparing a complex amplitude of the measurements in the two receive beams to a discriminator function.

The disclosure provides a method for estimating a direction of arrival of an L-type coprime array based on coupled tensor decomposition. The method includes: constructing an L-type coprime array with separated sub-arrays and modeling a received signal; deriving a fourth-order covariance tensor of the received signal of the L-type coprime array; deriving a fourth-order virtual domain signal corresponding to an augmented virtual uniform cross array; dividing the virtual uniform cross array by translation; constructing a coupled virtual domain tensor by stacking a translation virtual domain signal; and obtaining a direction of arrival estimation result by coupled virtual domain tensor decomposition. The present invention makes full use of the spatial correlation property of the virtual domain tensor statistics of the constructed L-type coprime array with the separated sub-arrays, and realizes high-precision two-dimensional direction of arrival estimation by coupling the virtual domain tensor processing, which can be used for target positioning.

Systems and methods are provided for a digital beamformed phased array feed. The system may include a radome configured to allow electromagnetic waves to propagate; a multi-band software defined antenna array tile; a power and clock management subsystem configured to manage power and time of operation; a thermal management subsystem configured to dissipate heat generated by the multi-band software defined antenna array tile; and an enclosure assembly. The multi-band software defined antenna array tile may include a plurality of coupled dipole array antenna elements; a plurality of frequency converters; and a plurality of digital beamformers.