A device may include a receive antenna input to couple a receive antenna to a receive chain of the device. The device may include a test signal generator to generate a test signal. The device may include a signal coupler between the receive antenna input and the receive chain. The signal coupler may include a first port to inject the first test signal into the receive antenna via the receive antenna input. The device may include a control circuit to monitor an impedance matching of the receive antenna based on one or more characteristics of a reflected signal resulting from the first test signal being injected into the receive antenna. The one or more characteristics of the reflected signal may be dependent on the impedance matching of the receive antenna.

Systems, methods and apparatus for automatic alarm management in a radio-frequency (RF) environment are disclosed. An apparatus calculates a power distribution by frequency of the RF environment in real time or near real time, including a first derivative and a second derivative of FFT data of the RF environment. The apparatus then creates a baseline based on the power distribution by frequency of the RF environment in a period of time, identifies at least one alarm situation based on a multiplicity of alarm triggering conditions by comparing the power distribution in real time or near real time to the baseline of the RF environment, identifies at least one signal based on the first derivative and the second derivative of FFT data in the at least one alarm situation, and sends at least one alarm comprising details of the at least one signal identified in the at least one alarm situation.

A method for radio measuring applications, wherein at least a first radio node operates as an initiator and at least a second radio node as a transponder, in a first step a first carrier frequency is transmitted by the initiator as an initial signal and received by the transponder. In a second step a response signal with a second carrier frequency is transmitted by the transponder and received by the initiator, during a measurement cycle at least one step sequence of the first and the second step is performed. First the first steps of all sequence of steps and subsequently at least a portion of the second steps of the step sequences are performed in succession, the first carrier frequency assumes a value within a predetermined frequency domain for each repetition, and the initial signals and the response signals are mutually coherent at least within the measurement cycle.

A device and a method for monitoring and analysis utilize unintended electromagnetic emissions of electrically powered components, devices or systems. The emissions are received at the antenna and a receiver. A processor processes and measures change or changes in a signature of the unintended electromagnetic emissions. The measurement are analyzed to both record a baseline score for future measurements and to be used in determining status and/or health of the analyzed system or component.

Disclosed herein is an exceptional points of degeneracy (EPD) system with a resonator by introducing a linear time-periodic variation. In contrast, prior art systems with EPD require two coupled resonators with precise values of gain and loss and a precise symmetry of inductances and capacitances. The disclosed EPD system only requires the tuning of the modulation frequency or modulation depth, which can be easily achieved in electronic systems. The EPD is a point in a system parameters' space at which two or more eigenstates coalesce, and this leads to unique properties not occurring at other non-degenerate operating points. Also disclosed are experimental data showing the existence of a second order EPD in a time-varying single resonator and the expected sensitivity of its resonances to circuit perturbations. The disclosed EPD system exhibits structural degenerate and non-degenerate resonances whose dynamics dramatically boosts its sensitivity performance to very small perturbations. The unique sensitivity induced by an EPD can be employed to create exceptionally-sensitive sensors based on a resonator by simply applying time modulation.

An apparatus for processing a signal by means of electromagnetic waves according to one embodiment of the present invention can, when a radio frequency (RF) signal is radiated onto a medium through any one of a plurality of channels, simultaneously receive the radiated RF signals which have been reflected or scattered by the medium or have penetrated the medium through the plurality of channels other than the channel through which the RF signal has been radiated.

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for detecting and classifying radio signals. The method includes obtaining one or more radio frequency (RF) snapshots corresponding to a first set of signals from a first RF source; generating a first training data set based on the one or more RF snapshots; annotating the first training data set to generate an annotated first training data set; generating a trained detection and classification model based on the annotated first training data set; and providing the trained detection and classification model to a sensor engine to detect and classify one or more new signals using the trained detection and classification model.

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.

A probe for measuring an electrical field includes at least three antennas, each antenna being adapted to receive a RF signal. The at least three antennas are arranged in accordance with three axes oriented perpendicularly to each other. A detection circuit is provided for each antenna, connected to the corresponding antenna for detecting an RF signal. A processing circuit is operationally connected to an output of each detection circuit for processing the detected signals and outputting a measurement result. A measurement correction mechanism is provided for correcting the measurement result based on a frequency of said electrical field and an angular position of the probe relative to said electrical field.

An automotive diagnostic tool includes an antenna, a speaker, and a controller. In response to a vehicle diagnostic request, the controller generates a carrier frequency that corresponds to a predetermined frequency associated with electromagnetic emissions from an imbalanced differential channel in the vehicle. The controller alternately enables and disables the differential channel resulting in an audio signature and a baseline audio signature. The controller demodulates signals from the antenna based on the carrier frequency and outputs the demodulated signal to the speaker for analysis by a listener. The demodulated signal may be further processed by the controller to identify emissions from the communication network.