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.

This disclosure provides techniques for impedance matching. A radio frequency (RF) device includes a power detector to determine a transmitter leakage and a post-processing unit to determine a receiver leakage, and determines if isolation is acceptable based on the leakages. The RF device may include a device for measuring antenna impedance. Otherwise, the RF device may select multiple tuner settings (e.g., capacitor values) for test signals to be transmitted and received at a target frequency, determine multiple sets of leakage values, determine multiple reflection coefficients based on the multiple sets of leakage values, and determine an estimated antenna impedance at the target frequency based on the reflection coefficients. The RF device then determines impedance tuner settings based on the measured or estimated antenna impedance. Alternatively, the RF device determines impedance tuner settings using an inverse machine-learning model based on a determined matching impedance.

Materials and methods for mitigating passive intermodulation. A membrane for reducing passive intermodulation includes a first polymeric layer, a second polymeric layer, and a continuous metal layer encapsulated between the first and second polymeric layers. A self-adhesive radio frequency barrier tape includes a waterproof polymeric top layer, a metal-containing layer adhered by an adhesive layer to the polymeric top layer, a pressure sensitive adhesive layer adhered to the metal-containing layer, and a release liner on a bottom surface of the pressure sensitive adhesive layer. A method of mitigating passive intermodulation includes passing a probe over an area of interest, the probe being sensitive to an intermodulation frequency of interest, and identifying a suspected source of passive intermodulation when the amplitude of the probe output exceeds a threshold at the frequency of interest. The method further includes covering the suspected passive intermodulation source with a radio frequency barrier material.

A method, network node and wireless device for phase error compensation for Fifth Generation downlink systems with four correlated uncalibrated antennas are provided. A method includes applying N incremented phase rotations to one of the four antennas to produce N channel state information reference signal resources, N being an integer greater than 1. The method also includes transmitting N CSI-RS on 4 CSI-RS ports to a wireless device, WD, each of the N CSI-RS resources being transmitted with a different one of the incremented phase rotations. The method further includes receiving from the WD a CSI-RS resource indication that indicates a particular one of the N CSI-RS resources. The method also includes applying, in subsequent transmissions to the WD, a phase rotation to the one of the four antennas, the phase rotation corresponding to the indicated CSI-RS resource.

The present disclosure relates to a pre-5.sup.th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4.sup.th-Generation (4G) communication system such as Long Term Evolution (LTE). An electronic device, in a wireless communication system, may include: a processor, an antenna array, a plurality of first radio frequency (RF) paths related to a first stream, the first RF paths each including a transmit (TX) path and a receive (RX) path, and a plurality of second RF paths related to a second stream, the second RF paths each including a TX path and an RX path, and the processor may be configured to: generate a calibration signal for the antenna array, obtain characteristic information of the antenna array based on a phase difference or a gain difference between one TX path having the first stream and one RX path having the second stream obtained for each of measurement RF paths among the plurality of the first RF paths, and calibrate the plurality of the first RF paths based on the characteristic information.

Embodiments include methods, performed by a user equipment (UE), for uplink (UL) transmission in a wireless network. Such methods include receiving a configuration associated with an UL transmission to a network node in the wireless network. Such methods include, for each of a plurality of combinations of the UE's available antennas and transmitters, determining metrics based on the UE performing the UL transmission using the particular combination. The metrics include a quality metric associated with reception of the UL transmission by the network node, and a UE energy consumption metric. Such methods include selecting one of the plurality of combinations of the available antennas and transmitters based on the respective quality metrics and the respective UE power consumption metrics, and performing the UL transmission according to the configuration and using the selected combination of available antennas and transmitters. Other embodiments include UEs configured to perform such methods.

A test system for determining a total radiated power of an antenna over the air comprises a measuring device and the base station. The measuring device is embodied to establish a communications connection to the base station to be tested over the air and to initiate and use over the air a function for fixing a present beam-lock function of the base station to be tested. The measuring device is further embodied to identify and measure a maximum effective isotropic radiated power, and to determine the total radiated power from previously known antenna characteristics and the measured maximum effective isotropic radiated power.

An operation system including: a prediction unit configured to determine a predicted value of a motion of an operator at a prediction time that is a time after elapse of a prediction time interval from the present using a predetermined machine learning model from a biomedical signal of the operator; a control unit configured to control a motion of a robot on the basis of the predicted value; and a prediction time setting unit configured to determine the prediction time interval on the basis of a delay time from a current value of the motion of the operator to the motion of the robot.

Apparatus and methods for retraining digital pre-distortion are disclosed. In certain embodiments, a mobile device includes a transmit chain and a front end system. The transmit chain generates a transmit signal and converts the transmit signal to a radio frequency input signal, and includes a digital pre-distortion circuit that provides digital pre-distortion to the transmit signal. The front end system includes a power amplifier that amplifies the radio frequency input signal to generate a radio frequency output signal, and a power detector that generates a detection signal based on detecting an output power of the power amplifier. The detection signal controls initiation of a retraining sequence of the digital pre-distortion circuit.

The present disclosure relates a switching matrix (100) comprising: a two-dimensional array of n input/output nodes (102), where n is equal to at least four; and a board comprising n network switches, one for each input/output node (102), each network switch coupling its corresponding input/output node to each of first and second switch connection points of the network switch; and, on a first side, a first switching network and on a second side, a second switching network.