The random component of mixer-based nonlinear vector network analyzer measurement uncertainty

The uncertainty, due to random noise, of the measurements made with a mixer-based nonlinear vector network analyzer are analyzed. An approximate covariance matrix corresponding to the measurements is derived that can be used for fitting models and maximizing the dynamic range in the measurement setup. The validity of the approximation is verified with measurements

Millimeter wave experiment for ATS-F

A detailed description of spaceborne equipment is provided. The equipment consists of two transmitters radiating signals at 20 and 30 GHz from either U.S. coverage horn antennas or a narrow beam parabolic antenna. Three modes of operation are provided: a continuous wave mode, a multitone mode in which nine spectral lines having 180 MHz separation and spaced symmetrically about each carrier, and a communications mode in which communications signals from the main spacecraft transponder are modulated on the two carriers. Detailed performance attained in the flight/prototype model of the equipment is presented both under laboratory conditions and under environmental extremes. Provisions made for ensuring reliability in space operation are described. Also described the bench test equipment developed for use with the experiment, and a summary of the new technology is included

Broadband Measurement of Error Vector Magnitude for Microwave Vector Signal Generators Using a Vector Network Analyzer

A frequency-domain method is proposed for the broadband measurement of error vector magnitude (EVM) for vector signal generators (VSGs). The technique is based on frequency-swept narrowband acquisitions performed with a vector network analyzer (VNA) by exploiting a stable (yet unknown) reference signal to obtain phase-repeatable measurements, eventually allowing to refer the residual distortion contribution of the analog VSG output to its digital input. The method leverages on the formulation of a novel measurement-based model, which accounts for the IQ imbalance effect and allows to separate it from the actual distortion within the VSG, ultimately yielding accurate broadband EVM measurements at microwave carrier frequencies without any time-domain waveform reconstruction, completely avoiding the use of broadband receivers and corresponding calibration

Measuring Receiver Benchmark for Conducted and Radiated Emissions Testing in Space Applications

This paper compares the measurement results obtained from three different implementations of measuring receivers regarding spectral level accuracy. The objective is to validate the suitability of direct sampling electromagnetic emissions measurements with respect to those delivered by a high-end EMI receiver in frequency swept and FFT modes. The experimental setups follow the verification methods described in the ECSS-E-ST-20-07C Rev.2 standard to set realistic and reproducible conditions. Between 50 kHz and 100 MHz, common mode and differential mode currents are measured when multisine excitation signals with controlled amplitude profiles are used as references. Subsequently, conducted and radiated emissions tests are run to investigate the correlation between measurements with the different receivers. The instruments used are a low-cost USB digitiser Picoscope PS5444D, a high-performance benchtop oscilloscope R&S RTO6 and the R&S ESW44 full-compliant EMI test receiver. The analysis concludes that the emissions measurements performed with the direct sampling approach are excellent for the intended application, exhibiting an accuracy comparable to the dedicated EMI test receiver and a well adequate dynamic range and noise level.The project (21NRM06 EMC-STD) has received funding from the European Partnership on Metrology, co-financed by the European Union's Horizon Europe Research and Innovation Programme and by the Participating States. EMC Barcelona's project under grant number SNEO-20211223 has received funding from CDTI, which is supported by "Ministerio de Ciencia e Innovación" and financed by the European Union - NextGenerationEU - through the guidelines included in the `Plan de Recuperación, Transformación y Resiliencia". Dr. Azpúrua has received funding from the StandICT.eu 2023 project, financed by the European Union's Horizon Europe - Research and Innovation Programme - under grant agreement No. 951972. Dr. Pous' work was supported in part by the European Union's Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement No. 801342 (TecniospringINDUSTRY) and the Government of Catalonia's Agency for Business Competitiveness (ACCIÓ) and in part by the Spanish "Ministerio de Ciencia e Innovaci´on" under project PID2019-106120RBC31/AEI/10.13039/501100011033

Twenty and thirty GHz millimeter wave experiments with the ATS-6 satellite

Studies at 11 locations in the continental United States were directed at an evaluation of rain attenuation effects, scintillations, depolarization, site diversity, coherence bandwidth, and analog and digital communications techniques using the Applications Technology Satellite-6(ATS-6). In addition to direct measurements on the 20- and 30-GHz links, methods of attenuation prediction with radars, rain gages, and radiometers were developed and compared with the directly measured attenuation. Initial data results of the ATS-6 millimeter wave experiment were presented. The first section describes the experiment objectives, flight hardware, and modes of operation. The remaining six sections present papers prepared by the major participating organizations in the experiment. The papers present a comprehensive summary of the significant results of the initial 11 months of ATS-6 experiment measurements and related radiometric, radar, and radio-meteorology studies

Waveform Approach for Assessing Conformity of CISPR 16-1-1 Measuring Receivers

An alternative approach for assessing the conformity of electromagnetic interference measuring receivers with respect to the baseline CISPR 16-1-1 requirements is proposed. The method’s core is based on the generation of digitally synthesized complex waveforms comprising multisine excitation signals and modulated pulses. The superposition of multiple narrowband reference signals populating the standard frequency bands allows for a single-stage evaluation of the receiver’s voltage accuracy and frequency selectivity. Moreover, characterizing the response of the weighting detectors using modulated pulses is more repeatable and less restrictive than the conventional approach. This methodology significantly reduces the amount of time required to complete the verification of the receiver’s baseline magnitudes, because time-domain measurements enable a broadband assessment while the typical calibration methodology follows the time-consuming narrow band frequency sweep scheme. Since the reference signals are generated using arbitrary waveform generators, they can be easily reproduced from a standard numerical vector. For different test receivers, the results of such assessment are presented in the 9 kHz–1 GHz frequency range. Finally, a discussion on the measurement uncertainty of this methodology for assessing measuring receivers is given.Postprint (author's final draft

Twenty and thirty GHz millimeter wave experiments with the ATS-6 satellite

The ATS-6 millimeter wave experiment, provided the first direct measurements of 20 and 30 GHz earth-space links from an orbiting satellite. Studies at eleven locations in the continental United States were directed at an evaluation of rain attenuation effects, scintillations, depolarization, site diversity, coherence bandwidth, and analog and digital communications techniques. In addition to direct measurements on the 20 and 30 GHz links, methods of attenuation prediction with radars, rain gages, and radiometers were developed and compared with the directly measured attenuation. Initial data results of the ATS-6 millimeter wave experiment from the major participating organizations are presented