In some implementations, an automated self-testing system may include an electric field source and a controller. The controller may detect a trigger event associated with initiating a self test of an electric field sensing device. The controller may cause, based on the trigger event, the electric field source to create a target electric field at a specific location sensed by the electric field sensing device. The controller may receive measurement data indicating a measured electric field strength, detected by the electric field sensing device, of the target electric field. The controller may determine, based on the target electric field strength and the measured electric field strength, whether the electric field sensing device passes the self test or does not pass the self test.

A test system for a vehicle-mounted antenna. In the test system, when a bearing face is connected to a reflecting plate or when the reflecting plate extends from the bearing face, the testing system for a vehicle-mounted antenna can be used for a semi-anechoic chamber test; and when the bearing face is not connected to the reflecting plate or when the reflecting plate is retracted into the bearing face, the test system for a vehicle-mounted antenna can be used for a fully anechoic chamber test. That is to say, the test system for a vehicle-mounted antenna not only has the fully anechoic chamber testing function, but also has the semi-anechoic chamber testing function, and the two functions can be conveniently switched by means of the mounting/removal or extension/retraction of the reflecting plate.

A calibration system for calibrating an electrochemical impedance spectroscopy (EIS) current measurement system can include a calibration resistor, which can have a specified resistance and an unspecified reactance, a reactive element which can have a specified reactance and an unspecified resistance, and a current source, which can be configured to provide a specified current through the reactive element, through the calibration resistor, and through a sense resistor arrangement of the EIS current measurement system to be calibrated, where the sense resistor arrangement can have a resistance and a reactance. The calibration system can also include voltage measurement circuitry, which can be configured to measure (1) a first voltage across the calibration resistor and a second voltage across the sense resistor arrangement and (2) a third voltage across the reactive element and a fourth voltage across the sense resistor arrangement, to determine a calibrated resistance value and a calibrated reactance value associated with the sense resistor arrangement.

The present disclosure relates to a calibration system for a vector network analyzer (VNA), having a plurality of N ports. The calibration system comprises a distribution unit having a plurality of DN ports; and a plurality of DN calibration units, respectively comprising a calibration circuit having first, second and third ports and an isolation circuit having first, second and third ports. For the respective calibration unit, the calibration circuit is configured to provide at least three different one-port calibration standards, such as open, short and match; the first port of the calibration circuit is arranged for being connected to a respective port of the VNA, the second port of the calibration circuit is connected to the first port of the isolation circuit, the third port of the calibration circuit is connected to a first matched load; the second port of the isolation circuit is connected to a respective port of the distribution unit, and the third port of the isolation circuit is connected to a second matched load. The distribution unit is configured to connect any one of its ports with all other of its ports.

Disclosed is a process for characterizing a fixture component of a test fixture. The fixture component comprises a test instrument interface and a device under test, DUT, interface. The process comprises connecting a test instrument to the test instrument interface; sequentially establishing a plurality of characterization setups for the fixture component; and characterizing at least one scattering, S, parameter of the respectively established characterization setup. The establishing respectively comprises one of: providing an open circuit at the DUT interface, providing a short circuit at the DUT interface, providing a further fixture component of the test fixture at the DUT interface via mated connectors, and providing a DUT at the DUT interface. This avoids inaccuracies, high cost and availability issues in connection with lead-out structures of test fixtures.

An apparatus to estimate parameters of a radio frequency (RF) signal may include a voltage sensor configured to provide an indication of a voltage of the RF signal as well as a current sensor configured to provide an indication of current conducted by the RF signal. The apparatus may additionally include an analog-to-digital converter coupled to an output port of the voltage sensor and the current sensor, wherein the analog-to-digital converter is configured to provide digital representations of an instantaneous voltage and an instantaneous current of the RF signal. The apparatus may additionally include one or more processors configured to transform the digital representations of the instantaneous voltage and current into frequency domain representations of a complex voltage and complex current.