An apparatus, a system and a method for finding a direction of a radio tag having a transmitter and at least one antenna for sending signals to the apparatus. The apparatus including a receiver; at least one antenna capable to form at least two directivity fields; and means for determining the direction of the apparatus by a first path signal received from the radio tag by the at least two directivity fields of the at least one antenna of the apparatus. The direction is found by turning the apparatus to a direction of the most intense directivity field of the first path signal until the field intensities of the two directivity fields are equal.

In one general aspect, RF localization methods and systems are disclosed. An exemplary method includes providing a node having a communications device and antenna elements; capturing, via the communications device, a relative signal strength indicator (RSSI) value for each antenna element to generate cardinal RSSI values associated with a RF signal; and determining, using the cardinal RSSI values, a position of a RF source of interest (RFSOI) relative to the node. The antenna elements are oriented in each nodal cardinal direction and conductively coupled to the communications device. The RF signal emanates from the RFSOI. Capturing the RSSI value for each antenna element may include causing a RF switch to successively activate the antenna elements in a predetermined order; capturing the RSSI value of each antenna element when activated; and determining at least two cardinal RSSI values that are greater than a predetermined amount thereby determining antenna elements of interest.

An RFID tag reading system and method estimate bearings of RFID tags. When the RSSI of a primary and/or secondary RFID receive signal is below a threshold, a primary receive beam is steered in a limited scan to an array of locations distributed around the location at which the RSSI of the primary receive signal is a maximum, and the RSSI of the primary receive signal is recorded at each location. The recorded RSSIs are processed to determine an effective weighted center of distribution of the recorded RSSIs, and the bearing for the tag based on the weighted center of distribution is thus estimated.

An RFID tag reading system and method estimate bearings of RFID tags. When the RSSI of a primary and/or secondary RFID receive signal is below a threshold, a primary receive beam is steered in a limited scan to an array of locations distributed around the location at which the RSSI of the primary receive signal is a maximum, and the RSSI of the primary receive signal is recorded at each location. The recorded RSSIs are processed to determine an effective weighted center of distribution of the recorded RSSIs, and the bearing for the tag based on the weighted center of distribution is thus estimated.

A compact, wideband antenna system includes first and second monopole radiating elements positioned near an edge of a common ground plane. The first and second monopole radiating elements may be located on opposite sides of the ground plane. Additional monopole elements may also be provided. In some embodiments, the ground plane includes an opening in a central region thereof to accommodate an optical system. In some embodiments, an additional antenna (e.g., an array antenna) may be provided over the same ground plane in a region between the monopole elements.

A method and an apparatus for aligning antenna beams in a high-low frequency co-site network, where the method includes performing antenna alignment of a low frequency beam with a communications device in order to establish a low frequency channel, and performing high frequency beam alignment of a high frequency antenna with the communications device using the low frequency channel. In the method, high frequency beam alignment of a high frequency antenna is performed using an established low frequency channel. Therefore, a technical problem that a high frequency beam alignment time of a high frequency antenna is long due to a narrow field of view of a high frequency beam can be avoided in order to quickly implement high frequency beam alignment of a high frequency antenna.

Lock system, mobile device and method for indicating the location of a lock with a mobile device, which mobile device sends and receives a radio signal and communicates with the lock via radio-frequency communication, wherein the lock is a lock that is openable electrically and by radio-frequency communication. In the solution of the invention the direction and/or strength of a radio transmission sent by a lock is measured with a mobile device, the location and/or direction of the lock in relation to the mobile device is determined on the basis of the measurement, and the location of the lock and/or the direction towards the lock is indicated with the mobile device to the user of the mobile device.

Lock system, mobile device and method for indicating the location of a lock with a mobile device, which mobile device sends and receives a radio signal and communicates with the lock via radio-frequency communication, wherein the lock is a lock that is openable electrically and by radio-frequency communication. In the solution of the invention the direction and/or strength of a radio transmission sent by a lock is measured with a mobile device, the location and/or direction of the lock in relation to the mobile device is determined on the basis of the measurement, and the location of the lock and/or the direction towards the lock is indicated with the mobile device to the user of the mobile device.

This disclosure describes methods and apparatus to promote sustainable usage of smartphones such as preventing phone loss, preventing overheating and overcharging, and decreasing packaging waste. A method and apparatus to prevent phone loss is disclosed. Radio frequency beacons (or tags) attached to the owner transmit signals to the smartphone. The distance of the owner from the smartphone is estimated based on the quality of the received radio frequency signals in the smartphone. The system alerts user whenever the distance gets farther than a preset value. A method and apparatus to prevent overcharging of the battery is also disclosed. A plugging mechanism is presented that will be automatically detached from the smart phone when the battery is fully charged. Moreover, an alerting system is disclosed that alerts the user to stop using the device when the internal temperature of the device gets hotter than a preset threshold.

A radar receiver (Rx) receives a reflected wave signal corresponding to a radar transmitting signal having been reflected on a target by using a plurality of antenna system processors (D1 to D4), and estimates an arrival direction of the reflected wave signal. A peak frequency selector (21) selects a peak value of a correlation vector. An adjacent time-frequency component extractor (22) extracts correlation vectors in number of (NE×NT−1) corresponding to NE Doppler frequencies and NT times respectively adjacent to a Doppler frequency and a time giving a peak value. A correlation matrix generating adder (23) generates a correlation matrix corresponding to correlation of the reflected wave signal received by a plurality of receiver antennas on the basis of the (NE×NT) extracted correlation vectors.