In accordance with a first aspect, a communication device is provided, comprising: a transmitter configured to transmit one or more radio frequency signal pulses to an external communication device; a receiver configured to receive one or more response signals in response to the radio frequency signal pulses transmitted by the transmitter; a signal analyzer configured to detect one or more characteristics of the response signals, to compare the detected characteristics with predefined reference characteristics and to generate an output indicative of a result of comparing the detected characteristics with the predefined reference characteristics; a processing unit configured to determine at least one category to which the external communication device belongs based on the output generated by the signal analyzer. In accordance with a second aspect, a corresponding method of operating a communication device is conceived. In accordance with a third aspect, a corresponding computer program is provided.

A system for sensing a proximity of a near field communication (NFC) device includes an NFC reader that communicates with a remote NFC device through load modulation. The NFC reader transmits a wireless carrier signal from an antenna, and the remote NFC device modulates such carrier signal by changing its internal impedance in order to transmit data to the NFC reader. The NFC reader has at least one antenna for receiving the modulated signal. This antenna is coupled to circuitry that measures a spectrum of the received signal and identifies a resonant frequency of the NFC device based on the measured spectrum. Such circuitry also determines the signal's amplitude at such resonant frequency and precisely estimates the distance of the remote NFC device from the reader based on such amplitude. By estimating the precise distance of the remote NFC device from the reader, the location of the remote NFC device relative to the reader can be precisely determined, and this information may be used to operate the NFC reader more efficiently.

Apparatus and methods are described, including apparatus that includes an antenna (34), configured to, by drawing energy from a magnetic field, provide a main supply voltage. The apparatus further includes operational circuitry (46, 22) configured to operate only if a derived supply voltage, derived from the main supply voltage and supplied to the operational circuitry, is greater than a threshold value, and modulating circuitry (36, 40, 42), configured to modulate a load of the antenna by alternatingly (i) connecting current-drawing circuitry to the main supply voltage, thus causing the main supply voltage to drop below the threshold value, and (ii) disconnecting the current-drawing circuitry from the main supply voltage without disconnecting the operational circuitry from the main supply voltage. Other embodiments are also described.

Specifically programmed, integrated motor vehicle dangerous driving warning and control system and methods comprising at least one specialized communication computer machine including electronic artificial intelligence expert system decision making capability further comprising one or more motor vehicle electronic sensors for monitoring the motor vehicle and for monitoring activities of the driver and/or passengers including activities related to the use of cellular telephones and/or other wireless communication devices and further comprising electronic communications transceiver assemblies for communications with external sensor networks for monitoring dangerous driving situations, weather conditions, roadway conditions, pedestrian congestion and motor vehicle traffic congestion conditions to derive warning and/or control signals for warning the driver of dangerous driving situations and/or for controlling the motor vehicle driver use of a cellular telephone and/or other wireless communication devices.

An electric composite detection antenna is disclosed. The antenna includes two RF antenna disposed on two sides of the circuit system of the electronic device, and a RF compensation system is disposed in the circuit system and includes an inductive sensing coil, and the induction coil can detect signal attenuation of any RF antenna subjected to external interference, so as to generate a detection signal. The RF compensation system can notice the control unit, to quickly drive any antenna matching circuit to switch to the RF antenna which is not interfered, or to quickly adjust antenna power or adjust the matching value of the RF antenna between the external environment, so that the preset electronic device can perform the stable transmission RF signal through the RF antenna without external interference, and maintain better power for RF signal transmissions.

The present invention discloses an antenna arrangement for 4.5G or 5G base station testing purposes. The antenna elements are placed in concentric rings and in a star-shaped arrangement around a center spot. All antenna elements within the same ring are controlled by the same amplitude and phase control signal. The test system processor also selects dedicated rings into use and switches the rest of the rings off. The ring spacing, i.e. the mutual antenna element distance along the same radial line will be determined based on highest frequency within the desired wide frequency band. A bowtie dipole type of antenna can be used. The antenna elements can be fixed on a printed circuit board, and thus, they remain mechanically stationary.

A batteryless wireless sensor system includes a data acquisition system, a radio frequency (RF) transceiver, and a batteryless wireless sensor device. The RF transceiver is in communication with the data acquisition system, transmits a RF signal, and receives sensor data and provide the sensor data to the data acquisition system. The batteryless wireless sensor device includes a RF transmitter, an analog to digital converter (ADC), and a sensor. The batteryless wireless sensor harvests energy from the RF signal and generates a DC signal based on the energy harvested from the RF signal, powers up and operates the ADC and the sensor based on the DC signal, and generates sensor data. The batteryless wireless sensor then transmits the sensor data via the RF transmitter to the RF transceiver. In certain examples, the ADC is implemented as a current mode ADC.

Systems and methods for multiphase power transfer in inductive couplers are provided. A system can include a first tubular having a first inductive coupler disposed on an outer surface thereof; a second tubular circumferentially disposed around the first tubular and forming an annulus therebetween; a second inductive coupler disposed on the second tubular; a first rectifier coupled to the second inductive coupler; a tank capacitor coupled to the first rectifier; and a load coupled in parallel with the tank capacitor.

A sensor location method includes placing an environmental sensor within an electromagnetic-absorbing material. The sensor is configured to sense a condition of the material and output sensor data representing the condition. The method includes providing a modulator configured to encode the sensor data onto a carrier at a carrier frequency. The method includes providing an amplifier, including a switch and a load network, in communication with a multi-turn coil. The switch can transition between on and off states. The network is coupled to the switch and the first multi-turn coil and includes a terminal that receives a voltage. The network is tunable to form a resonant circuit at the carrier frequency. The method includes generating a beacon signal whose amplitude is adjustable. The method includes receiving the beacon by a receiver outside of the material, measuring the received beacon amplitude, and determining the sensor location based upon the measured amplitude.

A sensor system is disclosed for sensing the position of an object. The system can include a power source and a nullification circuit electrically connected to the power source, the nullification circuit including an output voltage. An electrical medium can be integrated into the nullification circuit, the electrical medium producing a standing wave electric field about the electrical medium when power is supplied from the power source to the electrical medium. The nullification circuit is configured such that the output voltage of the nullification circuit is substantially zero when power is supplied to the electrical medium and the object is not within a predetermined minimum distance from the electrical medium, the output voltage of the nullification circuit having a non-zero value when the object is within the predetermined minimum distance from the electrical medium.