The present disclosure generally relates to an anechoic chamber for testing a device under test over-the-air, a system, and a method. The anechoic chamber includes at least one reflecting surface being configured to variably manipulate in a defined manner at least one reflection process of at least one electromagnetic wave usable for testing the device under test.

A method of simulating an effect of interactions between a device under test and a scattering object by of a hybrid over-the-air (OTA) test system is described. The method includes the steps of determining at least one radiation parameter of the device under test, wherein the at least one radiation parameter is associated with electromagnetic waves emitted by the device under test; determining an equivalent source on a Huygens surface based on the at least one determined radiation parameter, wherein the equivalent source is associated with the device under test; assigning material properties to a Huygens box confined by the Huygens surface, wherein the material properties are associated with at least one of reflection of electromagnetic waves and absorption of electromagnetic waves; and simulating an electromagnetic interaction between the device under test and the scattering object based on the determined equivalent source and based on the assigned material properties.

The present invention discloses an electromagnetic wave spatial analysis method based on multi-level dipole group modeling. The electromagnetic wave spatial analysis method includes the following steps: S1, obtaining a magnetic dipole group according to three-phase loops of power grids of various different voltage levels, and obtaining spatial coordinates of the magnetic dipole group according to the longitudes and latitudes as well as the altitudes of the power grids of various voltage levels; S2, calculating the loop length of each three-phase magnetic dipole according to the spatial coordinates of the magnetic dipole group, and obtaining a multi-level magnetic dipole group according to the loop lengths; S3, obtaining the current corresponding to the voltage on power transmission loops in the power grids of various voltage levels at different levels according to the installed capacities of the power grids of various voltage levels in different countries; S4, building a multi-level dipole model according to the multi-level magnetic dipole group and the current; and S5, solving the multi-level dipole model to obtain spatial power frequency electromagnetic wave distribution. The altitude factor of grid distribution is added in the present invention, and the power grids are divided into multiple levels for modeling analysis respectively, thereby increasing the analytical accuracy of power frequency electromagnetic waves.

The disclosure relates to technology for testing parameters of an antenna under test. The technology includes an antenna test bed, reference antenna and turntable for supporting the device and antenna under test. The turntable may be used to test the response of the antenna under test at different azimuth angles. Additionally, the reference antenna and turntable are integrated into a single test bed platform to ensure consistency and repeatability of test results.

A method employs an unmanned aerial vehicle to carry an electromagnetic field measurement system to overcome environmental obstacles in measuring environmental electromagnetic field. The electromagnetic field measurement system senses the electromagnetic field of a spatial position in the environment to generate a sensing signal, then processes the sensing signal to remove the high-frequency electromagnetic interference generated by the operation of the unmanned aerial vehicle itself from the sensing signal, and converts the processed sensing signal into a digital signal. The digital signal is processed to extract at least one wave according to a fundamental frequency and a harmonic order, thereby removing the low-frequency electromagnetic interference from the digital signal. The extracted wave is employed in calculating an environmental electromagnetic field value of the spatial location.

A device provides high impedance contact pads for an electrostatic charge sensor. The contact pads are shared between the electrostatic charge sensor and drivers. The contact pads are set to a high impedance state by reducing current leakage through the drivers. Compared to electrostatic charge sensor with low impedance contact pads, the electrostatic charge sensor disclosed herein has high sensitivity, and is able to detect weak electrostatic fields.

In some embodiments, an electric field generator includes a differential oscillator that oscillates at a nominal frequency. The electric field generator is connected to a differential antenna that radiates an electric field. A differential detector measures a frequency of the generated electric field as the electric field interacts with a body (such as a human body) in a reactive near-field region of the electric field. For each of one or more internal components of the body, a computation unit determines a respective periodic behavior in the measured frequency indicative of movement of the internal component. The computation unit also computes, for each of the one or more internal components of the body, a respective rate of movement (such as a heart rate or a respiration rate) of the internal component according to the respective periodic behavior in the measured frequency.

In some embodiments, an electric field generator generates an electric field at a nominal frequency and a nominal amplitude. The electric field generator is connected to an antenna that radiates the electric field. A detector measures a frequency and an amplitude of the generated electric field as the electric field interacts with a body (such as a human body) in a reactive near-field region of the electric field. For each of one or more internal components of the body, a computation unit determines a respective periodic behavior in the measured frequency corresponding to movement of the internal component. The computation unit also computes, for each of the one or more internal components, a respective rate of the movement of the internal component based on the determined respective periodic behavior in the measured frequency. A gain control circuit adjusts the nominal amplitude according to the measured amplitude.

An electric field gradient sensor is presented, having a sensor body having an outer surface; and a plurality of electrodes distributed over the outer surface, each electrode having an electrode surface facing outward from the surface. The plurality of electrodes are arranged forming a plurality of electrode pairs, each electrode pair formed by a first electrode and a second electrode located on opposite sides of the sensor body. This sensor enables three-dimensional measurements of the electric field gradient along structures located in an electrically conductive medium, such as subsea structures, for example for monitoring the cathodic protection of such structure.

A device is suitable for revealing spatial variations in polarization of an electromagnetic radiation, in a form of localized temperature variations. The device includes a surface of a carrier which is electrically and thermally insulating, and includes an array of patterns which each consist of at least one rectilinear segment of a sensitive material, of which the orientation is variable within each pattern or between neighboring patterns. Such device may be used with a thermal camera to reveal, in infrared images, temperature variations which are localized at segments not perpendicular to a local direction of linear polarization of the radiation.