Abstract: A device is arranged for distance measurement according to a ranging protocol using a measurement message from a second device. Based on a first arrival time of the measurement message a first distance (151) between the first device (110) and the second device (120) is determined. A third device (130) acts as a cooperating device that is located at a trusted distance (150). The cooperating device determines a third arrival time of the same measurement message, and transfers support data to the first device, the support data being based on the third arrival time. The first device obtains a third distance (153) between the third device and the second device using the support data. Then a verification test is performed on the first distance (151), the trusted distance (150) and the third distance (153). The first distance is reliable when said distances correspond to a viable spatial constellation (100) of the devices.

Abstract: This disclosure describes methods for contact tracing using information from devices for near-field communications (NFC), combined with auxiliary information from other (non-NFC) sensors such as inertial motion sensors (accelerometers and gyroscopes) and magnetometers. Methods using low-frequency NFC in the low MHz range of frequencies have the advantage of being robust in the presence of interfering objects, unlike other means of communication and proximity tracking using much higher frequency electromagnetic signals such as Bluetooth, GPS, and laser positioning. The method relies on unique features of NFC using inductively coupled devices to solve an optimization problem yielding the closest distance of approach of two NFC devices and can be adapted to handle multiple pairs of devices simultaneously. Location data is only required and generated in a local coordinate system (independent of absolute locations) which helps to preserve privacy.

Abstract: According to various embodiments, a method of controlling data communication of an electronic device, the method comprising performing the directional wireless communication together with an external electronic device capable of performing the directional wireless communication and the omni-directional wireless communication, by using the first wireless communication circuit, determining the distance between an electronic device and the external electronic device, at least partially on the basis of a signal of the external electronic device received by using the second wireless communication circuit, when the stop or degradation of the directional wireless communication is detected, and determining whether to reattempt the directional wireless communication using the first wireless communication circuit, at least partially on the basis of the determined distance or to start the omni-directional wireless communication using the second wireless communication circuit. Other embodiments are possible.

Abstract: TADF receivers for a navigation system, TADF navigation system and method using TADF material based navigation.

Abstract: A light fixture can include a housing and a sensor device having a sensor that measures at least one parameter associated with a position of the housing. The light fixture can also include a controller coupled to the sensor device. The controller can receive multiple measurements of the at least one parameter taken by the sensor device. The controller can also evaluate each measurement against at least one range of acceptable values. The controller can further send a notification when a measurement falls outside the at least one range of acceptable values. The notification can state that the housing is moved out of position and requires attention.

Abstract: The disclosure relates to technology for beam searching. Beam searching includes forming an omnidirectional radiation pattern by a group of antenna elements including one antenna element from each of one or more phased array antennas. In response to detection of beams from a transmitter, searching for one antenna element in the group according to a combined signal strength of each antenna element in the group; and enabling a phased array antenna with the one antenna element to align with the beams.

Abstract: A first wireless communication device includes transceiver circuitry to access data corresponding to a beamforming transmission, transmit, from the first wireless communication device to at least one second wireless communication device, a first sounding packet, and receive, from the at least one second wireless communication device, at least one second sounding packet. The second sounding packet includes channel feedback determined at the at least one second wireless communication device. Processor circuitry is to determine a steering matrix based on the channel feedback. The steering matrix is configured to at least one of reduce and avoid interference caused at the at least one second wireless communication device by transmissions from the first wireless communication device. The transceiver circuitry is further to perform the beamforming transmission to at least one third wireless communication device in accordance with the data corresponding to the beamforming transmission and the steering matrix.

Abstract: Methods and apparatus are set forth herein. Methods and apparatus can include for example: receiving for input into an non-linear device a radio signal, the radio signal being a composite signal composed of a signal of interest and an interfering signal, wherein the signal of interest and the interfering signal are at a common frequency; controlling a power level of the radio frequency input signal received at the non-linear device so that the non-linear device provides a non-linear effect; and processing an output signal output by the non-linear device to determine a characteristic of the signal of interest.

Abstract: A sensor antenna including a thin film material constructed in the shape of an antenna having a response, the material including a sheet resistance capable of being modified by an external stimulus where the antenna response varies over a range of sheet resistance values; method of making a sensor antenna; system including a sensor antenna; and method for operating a thin film sensor antenna including providing a thin film sensor antenna; exposing the sensor antenna to an external stimulus, simultaneously sensing the external stimulus while varying the sensor antenna response, measuring the change in the sensor antenna response, and correlating the measured response to a known change in the stimulus are disclosed.

Abstract: The solution described herein relates to using excess bandwidth on an interface to send measurement signals without or with limited beam forming in non-real time, i.e. allowing a delay. A Radio Equipment, RE and a method therein is provided. The method comprises receiving information on a plurality of antenna elements; deriving, from the received information, based on at least one beamforming matrix; information received in at least one pay-load beam, and providing the derived information to the REC over the interface. The method further comprises storing part of the received information not comprised in the at least one pay-load beam; and, when there is available capacity on the interface, given the providing of the derived information, at least part of the stored information is provided to the REC over the interface.

Abstract: A terrestrial communications network for providing broadband internet access to aerial platforms is described. One set of embodiments describe systems and methods for assigning aerial platforms to cell sites, and imposing a network frequency reuse pattern over the assigned beams, such as to optimize a certain network performance metric. Another set of embodiments describe systems and methods to iteratively optimize the aerial platform to cell site beam assignment, and the associated network frequency reuse pattern, according to the specified network performance metric. In other embodiments, systems and methods are described for measuring exogenous interference, to be used in SINR estimation received from different cell sites at the aerial platform in order to choose the cell site from which highest data rate is received.

Abstract: Systems and methods are disclosed herein which facilitate generating and utilizing look-up tables for determining an AoA of a radar signal received from an emitter. In example embodiments, the systems and methods may involve a selectivity process for selecting, for each of a plurality of installation positions, an installation-representative antenna pattern as selected from an option set. Thus, the selectivity process may, for example, include indexing a plurality of data sets of antenna patterns associated with an antenna position and selecting a most representative data set from at least one of the indexed data sets. In some embodiments, the system and methods may further apply a compression algorithm which identifies changes in slope with respect to adjacent pairs of antenna positions (vertex pairs) in the look-up table. The algorithm may then discard any antenna position (any vertex) that does not meet a slope difference threshold with respect to changes in the slope.

Abstract: Systems, methods, and processing nodes minimize interference in a wireless network. Minimizing interference includes determining that an angle between a first formed beam directed towards a wireless device and a relay signal directed towards a relay node is equal to or is less than a threshold angle. The wireless device can operate in a first area of network coverage, and the relay node operates in a second area of the network coverage. The first formed beam can interfere with the relay node upon the angle being equal to or less than the threshold angle. Minimizing interference also includes switching a connection of the relay node from a first access node to a second access node.

Abstract: Systems, apparatuses, and techniques for interference avoidance beamforming transmissions are described. A described apparatus can be configured to control a first channel sounding process with the first device to obtain first channel feedback regarding a wireless channel between the apparatus and the first device, determine, responsive to the first channel feedback, a first matrix to improve a performance of the beamforming transmission with respect to the first device, control a second channel sounding process with a second device to obtain second channel feedback regarding a wireless channel between the apparatus and the second device, determine, responsive to the second channel feedback, a second matrix to reduce interference leakage received by the second device during the beamforming transmission, and control the beamforming transmission to the first device based on the data and a steering matrix, the steering matrix being based on the first matrix and the second matrix.

Abstract: A system includes a processor configured to determine that a vehicle is in a parked state. The processor is also configured to detect a user device wireless signal, at one or more vehicle antennas. The processor is further configured to determine a primary return vector antenna based on the detected wireless signal and periodically broadcast a vehicle wireless signal from the one or more antennas, wherein if there is more than one antenna, the processor is configured to broadcast the signal more frequently from the primary return vector antenna. A mobile device can act responsively to the received signals, providing an indicator assisting in directional vehicle location.

Abstract: An apparatus for a radar antenna mapping system is described. The system comprises a plurality of antenna arrays configured to receive signals emitted from a transmitter. The system further comprises wherein the transmitter emits signals of a plurality of frequencies, wherein the transmitter is coupled to a component within a data center, and wherein each of the plurality of antenna arrays are configured to receive a signal of one of the plurality of frequencies. The plurality of antenna arrays each comprise a plurality of antenna elements configured to determine a location of the transmitter in a respective coordinate plane by receiving signals of one of the plurality of frequencies. The system further comprises a computer with a central processor configured to determine the location of the transmitter based upon the signals received by the plurality of antenna arrays and construct a map of the location of the component.

Abstract: An electric field intensity distribution measurement device 1 that measures, in a near field, a radio signal transmitted from an antenna 110 including a plurality of antenna elements T1 to TN integrated into a transmission device 100 includes a measurement antenna 11 that receives the radio signal as a measurement signal at a plurality of scanning points included in a predetermined scanning range, a reference antenna 12 that receives the radio signal as a reference signal, a phase difference and amplitude calculation unit 16 that calculates a phase difference between a measurement signal and a reference signal with respect to each scanning point, and an amplitude of the measurement signal, and a far-field electric field intensity distribution calculation unit 17 that calculates an electric field intensity distribution in a far field using information on the phase difference and the amplitude calculated by the phase difference and amplitude calculation unit 16.

Abstract: In an embodiment of the present invention, a method for transmitting a signal by a transmission point in a wireless communication system comprises the steps of generating complex modulation symbols for a terminal which is in a partially connected interference channel state; applying symbol extension to each of the complex modulation symbols, using a pre-coding matrix; and mapping the extended complex modulation symbols to resource elements, wherein the symbol extension is performed by multiplying an element of one column of the pre-coding matrix by each of the complex modulation symbols.

Abstract: Methods and apparatuses are provided which may be implemented in various devices having one or more computing platforms to obtain signaling characteristics for one or more transmitting devices. The signaling characteristics may, for example, be based, at least in part, on one or more signals received by a receiving device from the transmitting device(s), and may comprise at least a received signal strength measurement and a propagation time measurement. Such methods and apparatuses may further be implemented to determine whether a mobile station is to use or not use positioning data for one or more transmitting device(s) in a positioning function based, at least in part, on the received signal strength measurement and the propagation time measurement.

Abstract: Embodiments of the invention provide a system and method to improve the performance of a GNSS receiver using antenna switching. The system has a plurality of antennas and at least one radio frequency RF chain. There are fewer RF chain(s) than antennas. A receiver processes a plurality of signals sent by a plurality of transmitters. The system also includes antenna switches and switch controller. The method includes processing signals from a plurality of satellite vehicles SVs using an antenna selected from a plurality of antennas.

Abstract: A method for Link 16-based geolocation of hostile jammers comprising the steps of collecting jamming noise I/Q samples at a plurality of locations, determining the relative time delay of reception between two or more of the locations, determining the first derivative of the time delay of reception between the two or more locations, and using the results calculated in the preceding step to determine the position of the hostile jammers.

Abstract: The present invention relates to a method for determining the direction to a target by a direction finder, which comprises: predefining a direction axis as a 0° direction; first and second pair of antennas arranged such that a first line connecting between the first pair of antennae defines a 0°-180° axis parallel to said direction axis, and a second line connecting said second pair of antennas defines a 90°-270° axis perpendicular to said direction axis; generating a 0° antenna pattern and establishing a wireless communication between the direction finder and said target; attenuating the wireless communication signal until lost and recording the attenuation value; generating a 180° antenna pattern using said first pair of antennas, and establishing a wireless communication between the direction finder and said target; attenuating the wireless communication signal until lost, and recording the attenuation value and concluding a true direction to the target.

Abstract: A transmitter beamforming technique for use in a MIMO wireless communication system determines (i) a partial description of a reverse channel without determining a full dimensional description of the reverse channel and (ii) a partial description of a forward channel without determining a full dimensional description of the forward channel. A correction matrix is developed from the partial description of the reverse channel and a partial description of the forward channel. The correction matrix is used to process signals to be transmitted via the forward channel, and a steering matrix is used to perform beamforming in the forward channel.

Abstract: A directional antenna system for portable communication device that provides user control on the transmit antennas. The directional antenna system is made by two or more directional antennas with the directional antennas arranged in the pattern such that one of the directional antenna is pointing towards the user and the other directional antenna(s) are pointing away from the user. The directional antenna system is designed to cover a 360 degree circle in both the receiving and transmitting mode. In one of the transmitting mode, the portable communication device transmits RF signal on the directional antenna(s) that is pointing away from the user to minimize the electromagnetic energy exposure to the user. In the case when the RF receiving signal is below the desired operating condition on the outward pointing directional antenna(s), the portable communication device will generate an alert to the user.

Abstract: Systems and methods are provided herein that extend well-known direction finding (DF) and geolocation (GEO) concepts and approaches to a plurality of RF sensors to form a System of Systems (SoS) DF-GEO approach. The RF sensors may be collocated or spatial separated, and are able to exchange or share DF/GEO data. The SoS DF-GEO approach opportunistically leverages both on-board and off-board processing resources and DF-GEO measures for cooperative processing, situation awareness sharing, and performance optimization. The off-board processing resources and DF-GEO measures may be shared via networking. Thus, the SoS DF-GEO approach primarily bases measurements upon RSS or energy obtained from a one-antenna system or from a two-antenna system of a single RF sensor, as well as from other RF sensors via networking. By adopting the innovative SoS DF-GEO concept approach as described herein, optimized DF-GEO performance can be obtained by using the system of systems approach.

Abstract: A linear array of sensors includes at least two omni-directional sensors and at least one directional sensor, with the axis of sensitivity of the directional sensor arranged, e.g., perpendicular to the linear axis of the linear array. The omni-directional sensors and directional sensor receive a signal and in response produce output signals. The direction of arrival of the received signal is estimated with a 360° range using the output signals of the omni-directional sensors and directional sensor. For example, two symmetric solutions for the direction of arrival of the received signal may be determined using the output signals of the omni-directional sensors, and the output signal from the directional sensor is used to determine the correct solution.

Abstract: An arrival angle estimation system includes a transmitting device and a receiving device and estimates an arrival angle at which frames transmitted by radio from the transmitting device arrive at the receiving device. The transmitting device includes two directional antennas each arranged so that its directivity is tilted at ±? degrees with respect to the front of the transmitting device. The receiving device includes a directional antenna having directivity toward the front of the receiving device. Frames are transmitted alternately from the respective directional antennas of the transmitting device, and received signal strengths of the frames on the receiving device side for the respective transmitting directional antennas are compared with each other to estimate the arrival angle.

Abstract: Systems and methods for the selection of antennas in aircraft navigation systems are provided. In one embodiment, a navigation receiver system for an aircraft comprises: a first aircraft antenna that receives transmitter signals from fixed-location ground transmitters and a second aircraft antenna that receives transmitter signals from the fixed-location ground transmitters, wherein the first aircraft antenna has a first gain pattern that is different from a second gain pattern of the second aircraft antenna; a switch coupled to a first receiver and the first and second aircraft antenna; and a switch controller coupled to the switch. The switch controller operates the switch to electrically couple the first receiver to either the first or second aircraft antenna based on a determination of whether the first gain pattern or the second gain pattern provides higher gain in a direction of a first fixed-location ground transmitter of the fixed-location ground transmitters.

Abstract: A method and apparatus for estimating location of wireless stations in a wireless communication network are provided. An estimation of a bearing angle of a wireless station from a reference point of a multi-beam antenna pattern is made based on a plurality of beaming angles of a multi-beam antenna pattern and a received signal property, at the wireless station, of each of a plurality of wireless signals transmitted on respective beams of the multi-beam antenna pattern for each of the plurality of beaming angles.

Abstract: It is proposed a method for selecting an effective angle of reception of a directional antenna of a receiver node, the receiver node belonging to a wireless communications network comprising a plurality of emitter nodes. The method is implemented by the receiver node and comprises steps of: determining at least two possible angles of reception associated with a first emitter node, and for each of said at least two possible angles of reception, determining a difference between that angle and an angle of reception associated with a second emitter node different from said first emitter node, and selecting the effective angle of reception from among said at least two possible angles of reception associated with said first emitter node as a function of the determined differences.

Abstract: Systems and methods for monitoring, testing, and controlling alignment are provided, including an antenna assembly with an antenna and a receiver, the antenna configured to receive signals from a remote source, the receiver coupled to the antenna and configured to generate signal strength values associated with the signals from the remote source, and where the antenna assembly exhibits an azimuthal alignment relative to an axis determined by the antenna assembly and the remote source. Systems and methods provided herein further generate a first coarse-grained signal strength value from set of signal strength values generated by the receiver while the antenna assembly is at a first azimuthal alignment offset, and generate a measure that the first azimuthal alignment offset is at least one of: less than a predetermined azimuthal alignment offset, approximately equal to the predetermined azimuthal alignment offset, and greater than the predetermined azimuthal alignment magnitude.

Abstract: Techniques are provided which may be implemented using various methods and/or apparatuses to allow for expected signal data for a region of space within a structure to be encoded and transmitted to a mobile station. The mobile station may decode the encoded version and use the resulting decoded version to support signal-based position estimation.

Abstract: A method for locating a transmitter using a receiver which include, but are not limited to the steps of transmitting a plurality of distinctive and orthogonally polarized signals from a transmitter; receiving the transmitted signals at a pair of separated antennas; demodulating the distinctive orthogonal signals received at each of the pair of separated antennas; and determining a direction to the transmitter from the signals received at the pair of antennas.

Abstract: A method for determining whether a target is within a direction sector of interest of a direction finder and a device for carrying out the method are disclosed. The method calls for (a) predefining the sector of interest; (b) providing at least two antennas; (c) generating an in-phase reference pattern, and establishing wireless communication between the direction finder and the target; (d) attenuating the wireless communication signal between the direction finder and the target and recording the attenuation value which corresponds to the loss of wireless communication as the R reference value; (e) generating an out-of-phase null pattern, and re-establishing wireless communication between the direction finder and the target; (f) repeat step (d) except this time recording the attenuation value which corresponds to the loss of wireless communication as the N null value; (g) determining whether the difference R?N is above or below the threshold difference.

Abstract: The present invention relates to a method for determining the direction to a target by a direction finder, which comprises: predefining a direction axis as a 0° direction; first and second pair of antennas arranged such that a first line connecting between the first pair of antennae defines a 0°-180° axis parallel to said direction axis, and a second line connecting said second pair of antennas defines a 90°-270° axis perpendicular to said direction axis; generating a 0° antenna pattern and establishing a wireless communication between the direction finder and said target; attenuating the wireless communication signal until lost and recording the attenuation value; generating a 180° antenna pattern using said first pair of antennas, and establishing a wireless communication between the direction finder and said target; attenuating the wireless communication signal until lost, and recording the attenuation value and concluding a true direction to the target.

Abstract: An antenna system for estimating the DOA of arriving signals, comprising: a first omnidirectional antenna; and a second omnidirectional antenna, which is located coaxially above the first omnidirectional antenna at a predefined distance D. The first omnidirectional antenna is configured to transform the received arriving signal into output signals, and the second omnidirectional antenna is configured to transform the received signal into a reference signal. The antenna system allows extracting: a first phase difference between the phase of the first output signal and the reference phase and a second phase difference between the phase of the second output signal and the reference phase, where each phase difference includes a first component proportional to the azimuth of said arriving signal and a second component corresponding to the elevation of the arriving signal, from which the azimuth and the elevation of the arriving signal can be extracted.

Abstract: An exemplary radio-based navigation system uses a small multimode direction-finding antenna and a direction-finding receiver capable of determining platform position, velocity, attitude, and time while simultaneously providing protection against narrowband and broadband sources of interference. Global Navigation Satellite System (GNSS) signals such as those from the Global Positioning System (GPS) provide attitude measurements with a compact multimode direction-finding antenna (e.g., a small two-arm spiral with improved angle-of-arrival performance over the entire hemisphere enhanced through the use of a conductive vertical extension of the antenna ground plane about the antenna perimeter and/or conductive posts placed evenly around the antenna perimeter) which provides simultaneous protection against jammers. The multimode spiral may be treated as an array of rotationally-symmetric antenna elements.

Abstract: Provided is a radio control method for a radio communication being performed in a beam direction that is set on the basis communication quality basis, including a step of acquiring a data string formed of at least a beam direction and communication quality in the beam direction; and a step of sequentially assigning a priority rank for setting the beam direction for performing the radio communication from the beam direction in which the highest communication quality is obtained, according to the data string. In the step of assigning a priority rank, no priority rank is assigned to the beam direction adjacent to the beam direction to which a priority rank has been already assigned or to the beam direction in the vicinity containing the adjacent beam direction.

Abstract: Methods and systems for dynamic tracking utilizing leaky wave antennas (LWAs) are disclosed and may include configuring a transmitting angle of a plurality of leaky wave antennas in a wireless device at a desired starting angle. A RF signal strength may be measured at the sweeping transmitting angles for each of the leaky wave antennas, and a location of one or more objects may be tracked from the measured RF signal strength and a corresponding angle of reception of the LWAs. A resonant frequency of the LWAs may be configured utilizing micro-electro-mechanical systems (MEMS) deflection. The LWAs may be situated along a plurality of axes in the wireless device. The LWAs may comprise microstrip or coplanar waveguides, where a cavity height of the LWAs is dependent on spacing between conductive lines in the waveguides. The LWAs may be integrated in integrated circuits, integrated circuit packages, and/or printed circuit boards.

Abstract: A method and apparatus for a communication system having a first transceiver device having a first plurality of antennas and a second transceiver device having a second plurality of antennas determines a channel estimation matrix describing a forward channel in which a signal travels from the first transceiver device to the second transceiver device. The channel estimation matrix is decomposed to derive a unitary matrix and an upper triangular matrix. A precoding matrix is developed using the upper triangular matrix, and the precoding matrix is used to control transmission of a modulated signal.

Abstract: The invention provides a determination of direction to a remote object which omnidirectionally transmits a signal. The invention includes a handheld directional and omnidirectional antenna at a user's location and a handheld circuit coupled to the antennas to determine field strengths of the signal received from the remote object by the two antennas. A comparison of the received signals at the antennas during a sweep a field of observation is made and a probable direction of the remote object relative to the user's location is selected from the data sweep. The apparatus may further comprise a digital compass which generates a compass heading corresponding to each direction in which the directional antenna is pointed. The circuit stores field strength data by compass heading and averages the field strength data according to a predetermined protocol over compass headings.

Abstract: In a transmitter or transceiver, signals can be precoded by multiplying symbol vectors with various matrices. For example, symbol vectors can be multiplied with a first column subset of unitary matrix which spreads symbols in the symbol vectors across virtual transmit antennas, a second diagonal matrix which changes a phase of the virtual transmit antennas, and a third precoding matrix which distributes the transmission across the transmit antennas.

Abstract: A beam switching antenna method and apparatus for controlling a beam switching antenna system including an antenna element for forming a beam, at least one conductive reflector for reflecting the beam, and a ground switch for applying a reference voltage to the least one conductive reflector, the method including selectively configuring the beam switching antenna system for a current-directional beam pattern to receive a first signal and for a non-directional beam pattern to receive a second signal; comprising the first and second signals; and controlling, using the ground switch; the beam based on the comparison of the first and second switching.

Abstract: A method and device for wireless directional beam-forming transmission. The method for wireless directional beam-forming transmission between a first device and a second device comprises conducting one or more omni-directional transmissions between the first device and a third device; conducting one or more omni-directional transmissions between the second device and the third device; and determining directional information for directional beam forming transmissions between the first and second devices based on the omni-directional transmissions.

Abstract: An advanced multiple-beam GPS receiving system is achieved that is capable of simultaneously tracking multiple GPS satellites independently, detecting multiple interference signals individually, and suppressing directional gain in the antenna pattern of each beam in the interference directions. The GPS receiving system can be used for both planar and non-planar receiving arrays, including arrays that are conformally applied to the surface of a platform such as an aircraft. The GPS receiver combines spatial filtering and acquisition code correlation for enhanced rejection of interfering sources. Enhanced gain in the direction of GPS satellites and the ability to shape the beam patterns to suppress gain in the direction of interfering sources make the GPS receiving system largely insensitive to interfering and jamming signals that plague conventional GPS receivers.

Abstract: An antenna system comprising a first antenna element, a second antenna element, and a parasitic element, wherein the parasitic element is arranged with regard to the first antenna element and the second antenna element such that a greatest difference in gain between respective antenna patterns of the first and second antenna elements occurs at a null of the pattern of the first antenna element.

Abstract: The invention relates to a method for determining whether a target is within a direction sector of interest of a direction finder, which comprises: (a) predefining said sector of interest as a specific threshold difference between an R reference value and an N null value; (b) providing at least two antennas arranged in a broad-side configuration within the direction finder; (c) generating an in-phase reference pattern using at least one of said antennas, and establishing wireless communication between the direction finder and said target; (d) attenuating the wireless communication signal between the direction finder and said target until the wireless communication is lost, and recording the attenuation value which corresponds to said loss of wireless communication as the R reference value; (e) generating an out-of-phase null pattern using at least two of said antennas, and re-establishing wireless communication between the direction finder and said target; (f) attenuating the wireless communication signal bet

Abstract: A technology for providing an arrival direction estimation apparatus which can greatly reduce the calculation amount in spectrum calculation and can perform precise direction estimation without setting short frequency division in spectrum calculation is disclosed.

Abstract: A radar sensor receives a radar wave signal through a radome in each of antennas while judging existence of an attenuating thing in a detecting unit. This unit extracts a maximum level channel from receiving channels assigned to the antennas every modulation period, calculates a difference in signal level between the maximum level channel and each receiving channel every modulation period, sets each receiving channel corresponding to large level differences in one measuring period including plural modulation periods as a candidate channel every measuring period, increments a preliminary variable of each candidate channel every measuring period, increases a final variable each time the preliminary variable of at least one receiving channel reaches or exceeds a preliminary value in one measuring period, and judges in response to the final variable reaching a final value that the attenuating thing attenuates the radar wave directed toward the random.

Abstract: An apparatus for tracing position and direction of a target object through an RF signal includes two loop antennas and a position and direction determination part. The two loop antennas receive the RF signal transmitted from the target object and are perpendicularly coupled to each other. The position and direction determination part calculates two RF signal intensities received through the respective two loop antennas for comparison, and then determines that the target object transmitting an RF signal is placed in a center direction between the two loop antennas if the two RF signal intensities are the same, and otherwise determines that the target object is placed in a front direction of the loop antenna having a relatively higher RF signal intensity.