A multi-panel base station test system includes a base station radio unit configured with a plurality of antenna panels positioned at a first end of a test chamber of the multi-panel base station test system. The multi-panel base station test system includes a plurality of test antennas positioned at a second end of the test chamber opposing the first end. The multi-panel base station test system includes a microwave lens positioned between the plurality of antenna panels and the plurality of test antennas in the test chamber. The microwave lens is configured to focus respective beams transmitted from each of the plurality of antenna panels toward respective focal points associated with each of the plurality of test antennas based on steering of the plurality of antenna panels.

A signal transmission apparatus includes: a shielding cabinet and at least one group of first signal transceiver assemblies, at least one antenna assembly, and a first installation structure that are disposed inside the shielding cabinet, where the first installation structure has a one-to-one correspondence with the at least one group of first signal transceiver assemblies, each antenna assembly includes an antenna probe and a signal cable that are connected to each other, and the antenna probe performs, by using the signal cable, signal transmission with another signal transmission apparatus disposed outside the shielding cabinet; signal transmission is performed between the first signal transceiver assembly and the antenna probe in a wireless manner; and each first installation structure can drive a corresponding group of first signal transceiver assemblies to move.

In a general aspect, vapor cells are disclosed that include a dielectric body having a first surface and a second surface. The dielectric body includes a plurality of cavities extending from the first surface to the second surface and ordered periodically to define a photonic crystal structure in the dielectric body. Each cavity has a first opening defined by the first surface and a second opening defined by the second surface. The photonic crystal structure has a photonic band gap. The vapor cells additionally include a first optical window covering the first openings and having a surface bonded to the first surface of the dielectric body to form a seal around each of the first openings. A second optical window covers the second openings and has a surface bonded to the second surface of the dielectric body to form a seal around each of the second openings.

A method for emulating an electromagnetic environment, EME, in an anechoic chamber comprises the steps of: receiving, by a first receiving unit, an input signal outside the anechoic chamber; generating, by a signal generating unit, an emulated signal based on the input signal; transmitting, by a transmitting unit, the emulated signal inside the anechoic chamber to emulate the EME; receiving, by a second receiving unit, the emulated signal inside the anechoic chamber; and adjusting, by the signal generating unit, the emulated signal generated by the signal generating unit based on the emulated signal received by the second receiving unit.

Embodiments relate to functional test methods useful for fabricating products containing Light Emitting Diode (LED) structures. In particular, LED arrays are functionally tested by injecting current via a displacement current coupling device using a field plate comprising of an electrode and insulator placed in close proximity to the LED array. A controlled voltage waveform is then applied to the field plate electrode to excite the LED devices in parallel for high-throughput. A camera records the individual light emission resulting from the electrical excitation to yield a function test of a plurality of LED devices. Changing the voltage conditions can excite the LEDs at differing current density levels to functionally measure external quantum efficiency and other important device functional parameters. Spectral filtering is used to improve measurement contrast and LED defect detection. External light irradiation is used to excite the LED array and improve onset of charge injection light emission and throughput.

A system includes a vacuum chamber to receive a laser beam and a charged nanoparticle. The nanoparticle oscillates at a trapping frequency in a focus of the laser beam. Resonant oscillation of the nanoparticle is driven by a presence of an ambient electric field adjacent to the vacuum chamber. The system also includes a controller to tune the trapping frequency of an oscillating nanoparticle to be in resonance with the ambient electric field causing on-resonant enhancement of the system; a detector to detect positional changes of the oscillating nanoparticle; and a processor to calculate an electromagnetic force of the ambient electric field based on the positional changes of the oscillating nanoparticle.

An assembly for characterizing a device under test (DUT) (2), comprising a dome (5) forming a test chamber. The assembly further comprises a plurality of sampling units (4), wherein during characterization of the DUT (2) the plurality of sampling units (4) are static with respect to the DUT (2) and the dome (5), and spatially distributed over the dome (5) in a far-field range of the DUT (2). The plurality of sampling units (4) are configured to receive a signal inside the test chamber, and transmit an output signal based on the received signal for further analysis. In a further aspect, a method for characterizing a DUT (2) is also provided.

A measuring system for measuring properties of a device under test over the air comprises an antenna array, adapted to receive first measuring signals from the device under test, a measuring device adapted to process the first measuring signals received by the antenna array, and to generate second measuring signals and transmit them to the device under test, using the antenna array. The measuring device comprises a quiet zone generator, which is adapted to perform a beamforming of the first measuring signals after reception by the antenna array. It is preferably also adapted to perform a beamforming on the second measuring signals before transmission by the antenna array. The quiet zone generator is adapted to apply the beamforming, so that at least one adjustable quiet zone is achieved.

An EMC test system for a rotating load includes a shielded chamber, a rotating load, a first connecting shaft, a compressor, a fluid pipeline, a fluid motor, a second connecting shaft and a motor load. The rotating load, the first connecting shaft and the compressor are arranged inside the shielded chamber. The fluid motor, the second connecting shaft and the motor load are arranged outside the shielded chamber. The rotating load is connected to the compressor through the first connecting shaft. The compressor is connected to the fluid motor through the fluid pipeline. The fluid motor is connected to the motor load through the second connecting shaft. The fluid pipeline passes through the shielded chamber. The compressor is employed such that energy is transferred to the outdoors through the transmission of fluid, and then converted into electric energy.

A method for positioning a device under test within a test area is provided. The method comprises the steps of determining shape and/or quality of a quiet zone with respect to the device under test, and using an augmented reality technique in order to optimize the positioning of the device under test in the quiet zone.