The High Energy Cosmic Radiation Detector (HERD) is scheduled for deployment on the China Space Station in 2029. As a key payload subsystem of HERD, the transition radiation detector (TRD) is designed to support high-precision energy calibration and observations in the TeV energy range. However, the reliability of lower-grade commercial off-the-shelf (COTS) chips used in the TRD has not been fully validated in the space radiation environment, in which single-event effects (SEE) may occur. To address this issue, we propose a modular radiation-hardness evaluation system consisting of a main control board, multiple device-under-test (DUT) boards, and a host computer. Separation between the main control board and the DUT boards enables flexible configuration and rapid evaluation across chip types, while the host computer provides real-time data visualization, remote control of SEE tests, and automatic data archiving for subsequent analysis. This system was used to conduct heavy-ion irradiation tests on key COTS chips used in the TRD. Under a tantalum (Ta) ion beam with LET 75 MeV·cm2/mg, no SEE were observed in any tested chip. Based on Poisson statistics, we derived an upper bound on the SEE cross section for the considered chips, σ SEE < 3 × 10-7 cm2/chip @ 95% C.L., supporting the conclusion that these chips exhibit low susceptibility to SEE.The experimental results demonstrate the radiation robustness of the selected TRD chips and validate the reliability of the proposed test system for SEE evaluation in space applications.

The optimal design of electromagnetic interference (EMI) filters relies on accurate characterization of noise source impedance. The conventional insertion loss method involves integrating two distinct passive two-port networks between the linear impedance stabilization network (LISN) and the equipment under test (EUT). The utilization of the insertion loss to formulate a system of binary quadratic equations concerning the real and imaginary components of the impedance of the noise source enables the precise extraction of the magnitude and phase of the noise source impedance in theory. However, inherent inaccuracies in the insertion loss method during extraction can compromise impedance accuracy or even cause extraction failure. This work employs a series inductance method to overcome these limitations. Exact analytical expressions are derived for the magnitude and phase of the noise source impedance. Subsequently, the application scope of the series insertion loss method is analyzed, and the impact of insertion loss measurement error on noise source impedance extraction accuracy is quantified. Requirements for improving extraction accuracy are discussed, and method optimization strategies are proposed. The permissible range of insertion loss error ensuring a solution exists is deduced. Finally, simulation and experimental results validate the proposed approach in a buck converter.

Abstract This paper studied the influence of nearby metal on the surface magnetic field test. Two surface magnetic field testing systems based on the diamond NV (Nitrogen-Vacancy) center and the small-loop antenna are established. A coplanar waveguide is presented as the device undertest. An aluminum rod is used as a metal interferent and is placed close to the coplanar waveguide and magnetic field probes. It is found that changing the distance between the aluminum rod and the measured coplanar waveguide causes 6%~26% decrease of the meased magnetic field intensity based on the small-loop antenna. But it has almost no effect on the magnetic field tested results based on the NV center. Accordingly, the magnetic field test method based on NV center is suitable for measuring scenes with metal interferences around it.

ABSTRACTReverberation chambers are essential facilities for electromagnetic compatibility testing, and their internal field uniformity critically determines the accuracy of test results. The current IEC 61000‐4‐21 standard primarily restricts the size of the Equipment Under Test (EUT) based on its physical volume, recommending it not exceed 8% of the total RC volume. However, this empirical guideline overlooks critical factors such as the EUT's electrical size and geometric shape, leading to significant limitations. This paper employs both the Plane Wave Superposition (PWS) method and full‐wave Multi‐Level Fast Multipole Method (MLFMM) simulations to systematically investigate the impact of various EUT types on field uniformity. Our findings reveal that an EUT's electrical size and shape are often dominant factors in perturbing the field uniformity, demonstrating that the physical volume ratio criterion alone is insufficient for ensuring test validity. Simulation results show that some EUTs compliant with the 8% rule still cause excessive field degradation, while some larger EUTs do not. The comparison between simulation methods also highlights that full‐wave simulations, which capture the complete EUT‐cavity coupling, are essential for accurately assessing the actual loading effect. This research provides in‐depth analysis and a comprehensive simulation dataset that challenge the adequacy of the current standard.

Abstract This paper presents a method for measuring whole-body specific absorption rate (WBSAR) of millimeter-wave base stations (BSs) in a reverberation chamber (RC). The absorbed power in the phantom from the equipment under test (EUT) and hence WBSAR is determined as the difference between the total radiated power with and without the phantom. A chamber transfer function is determined and used to include only the absorption in the phantom due to direct illumination from the EUT, i.e., excluding absorption due to the RC multipath reflections. The measurement method was evaluated at 28 GHz using a horn antenna and a commercial massive multi-input–multi-output BS. The experimental results are in good agreement with simulations. The proposed method allows for measurements of WBSAR within 3 minutes, which is much shorter than traditional approaches. The method is suitable for compliance assessments of BS products with the International Commission on Non-Ionizing Radiation Protection 2020 electromagnetic field exposure guidelines, which extend the applicability of WBSAR as basic restrictions up to 300 GHz.

In this study, the degradation characteristics of radio frequency (RF)-low-noise amplifiers (LNA) due to a total ionizing dose (TID) is investigated. As a device-under-test (DUT), sample LNAs were prepared using silicon–germanium (SiGe) heterojunction bipolar transistors (HBTs) as core elements. The LNA was based on a cascode stage with emitter degeneration for narrowband applications. By using a simplified small-signal model of a SiGe HBT, design equations such as gain, impedance matching, and noise figure (NF) were derived for analyzing TID-induced degradations in the circuit-level performance. To study radiation effects in circuits, the SiGe-RF-LNAs fabricated in a commercial 350 nm SiGe technology were exposed to 10-keV X-rays to a total ionizing dose of up to 3 Mrad(SiO2). The TID-induced performance changes of the LNA were modeled by applying degradation to device parameters. In the modeling process, new parameter values after irradiation were estimated based on information in the literature, without direct measurements of SiGe HBTs used in the LNA chip. As a result, the relative contributions of parameters on the circuit metrics were compared, identifying dominant parameters for degradation modeling. For the TID effects on input matching (S11) and NF, the base resistance (RB) and the base-to-emitter capacitance (Cπ) of the input transistor were mostly responsible, whereas the transconductances (gm) played a key role in the output matching (S22) and gain (S21). To validate the proposed approach, it has been applied to a different LNA in the literature and the modeling results predicted the TID-induced degradations within reasonable ranges.

Electric near-field scanning for electronic PCB electromagnetic radiation measurement

The thermal vacuum test (TVT) is an important verification process in the development of spacecraft and load. There are often multiple temperature points on the device under test (DUT) that require control. The interaction among multiple channels poses a challenge for temperature control in the TVT. To solve this problem, a multi-channel Smith proportional–integral–derivative (PID) controller based on a grouping neural network (Grouping-NN) is proposed. Firstly, the mathematical derivation for a typical multi-channel temperature control model of the TVT is carried out. Then, the multi-channel interaction system is identified using a Grouping-NN to predict the output temperature of each channel by grouping the hidden layer neurons according to the number of channels. Finally, two Grouping-NNs are utilized to update the Smith predictor, and the time-delay error is fed back to the PID controller, which is used to optimize the control effect of the multi-channel interaction system under high time delay. The proposal is compared with the traditional PID controller and Smith predictor-based PID controller through simulation. The simulation results show that the proposed method has better suppression of overshooting. In addition, the algorithm is verified by controlling the temperature of six channels in a practical thermal vacuum test.

Abstract This article presents measurement circuits and a test board developed for the experimental evaluation of prototype chip samples of the Fully Differential Difference Amplifier (FDDA). The Device Under Test (DUT) is an ultra low-voltage, high performance integrated FDDA designed and fabricated in 130nm CMOS technology. The power supply voltage of the FDDA is 400mV. The measurement circuits were implemented on the test board with the fabricated FDDA chip to evaluate its main parameters and properties. In this work, we focus on evaluation of the following parameters: the input offset voltage, the common-mode rejection ratio, and the power supply rejection ratio. The test board was developed and verified. The test board error was measured to be 38.73mV. The offset voltage of the FDDA was −0.66mV. The measured FDDA gain and gain bandwidth were 48dB and 550kHz, respectively. In addition to the measurement board, a graphical user interface was also developed to simplify the control of the device under test during measurements.

The escalating component density in radio frequency (RF) systems presents a growing challenge related to the coupling of adjacent microstrip lines in high-density printed circuit boards (PCBs). As a result, to tackle this prominent issue, there is a continuous pursuit of innovative techniques to effectively minimize the coupling effects among closely spaced microstrip lines. This paper proposes a reduction in the coupling of adjacent lines by utilizing a coating (stiffener) layer, which is commonly used in rigid-flex PCB fabrication. For this purpose, a reference 50 Ohm coupled line performance was compared to three coupled lines with track widths of 1.39 mm, 1.30 mm, and 1.25 mm, respectively, all at a fixed distance between the tracks. These decreasing widths were used to achieve the same 50 Ohm impedance for the coupled lines when covered with different coating layers. Each of these three coupled lines was covered with different coating (stiffener) layers, measuring 0.1 mm, 0.3 mm, and 0.5 mm in thickness, respectively. The manufactured device under test (DUT) structures underwent time-domain reflectometry (TDR) and S-parameter measurements. The TDR measurements of the DUT structures with coating layers demonstrated excellent conformity to the 50 Ohm reference coupled line. Meanwhile, the S21 measurements indicated a significant decrease in the crosstalk. For example, for a coating layer thickness of 0.3 mm, the crosstalk decreased by approximately 5–6 dB within the frequency range up to 5 GHz. When the coating layer thickness was 0.5 mm, the crosstalk decreased by approximately 10 dB or more.

Influence of electron beam irradiation induced charging-effect on nanoprobing localization of a crystal defect in MOSFET

A novel in-situ approach to monitor the variations in the on-resistance of power transistors during switching operation

We present a method of tomography in which photon pairs from a device-under-test (DUT) are experimentally characterised by quantum interference with a reference photon pair source; we call this quantum-referenced spontaneous emission tomography (Q-SpET). In Q-SpET, the joint spectral phase (JSP) of photon pairs generated by a DUT can be reconstructed by combining four spectrally resolved interferograms. We demonstrate this theoretically and experimentally, characterising the JSP of a microresonator photon pair source. Our method is fully implemented on a chip, demonstrating the compactness, inherent phase stability, low complexity, and resource efficiency of this method.

In this work, the design of a load-modulated balanced power amplifier (LMBA), which is composed of a pair of classical balanced power amplifier (BA) and a signal control power amplifier (CA), based on using the X-parameter model is presented for the first time. A 10-W gallium nitride (GaN) packaged transistor is used for the power amplifier (PA) design. The extracted X-parameter model of the device under test (DUT) can accurately predict the nonlinear behavioral of the device, including both fundamental and harmonic characteristics, and determine the region of the Smith chart that leads to the optimal output power and drain efficiency (DE), with which the BA and CA are designed. In order to facilitate the application of the X-parameter for LMBA design, the X-parameter model of the classical BA pair is further extracted. Finally, an LMBA is fabricated and tested to verify the validity of the proposed design methodology. The measurements performed on the developed prototype show a saturation output power of up to 43.2 dBm in the frequency range of 1.3–1.6 GHz, with a saturation DE over 73% and an output power back-off (OBO) efficiency over 51% when it has more than 9-dB OBO. A single-carrier 20-MHz long-term evolution (LTE) signal is used to test the designed PA, and performance of the amplifier both with and without linearization are given.

A Line Impedance Stabilization Network (LISN) is a crucial tool in the field of electromagnetic compatibility (EMC) testing and measurement. Its primary purpose is to ensure that conducted emissions from electrical and electronic devices are accurately measured in a controlled and standardized manner. After both circuit simulation in LTSpice firstly input noise simulation without LISN in first circuit and after that second circuit simulation in which we simulate input noise simulation with LISN we reached on the final conclusion is that by stabilizing the impedance of the power supply line, LISNs help filter out external interference and noise, allowing for precise measurements of the emissions generated by the DUT. They provide a standardized impedance interface between the device under test (DUT) and the measuring equipment, ensuring consistent and repeatable EMC testing results. We get desired result after simulation when we analysis both circuit simulation in details we get 33% improvement in frequency, noise decreases in terms of frequency and we get 3% improvement in power at output in LISN applying circuit.

Conducted emissions (CE) for three-phase systems are becoming an increasing concern due to the recent exponential growth of three-phase applications, especially linked to the automotive sector. The problem arises because electromagnetic compatibility (EMC) standards only define the methodology to measure the CE generated by the equipment under test (EUT), and they do not provide sufficient information to design a power line filter (PLF) in case of non-compliance. Hence, the design of an optimal PLF is a very difficult task for engineers. The unclear methodology to be followed, unknown load impedances, inadequate equipment, and lack of knowledge of the modal noise are all different reasons that contribute to increasing the PLF design complexity. Common mode (CM) and differential mode (DM) decomposition and PLF design techniques for single-phase EUTs are well discussed and studied in the literature, but the same cannot be stated when it comes to three-phase PLF design. The objective of this paper is to clarify how modal noises behave in a three-phase system and to propose a clear methodology which can be followed to design an optimal three-phase PLF. Additionally, this paper analyses and discusses the modal noises’ intrinsic behavior and provides an understanding of how the PLF components behave when subjected to either a CM or DM noise. Finally, a methodology to design a three-phase PLF, based on accurate insertion loss (IL) estimations and S-parameter measurements, is used to determine the optimal PLF. This approach is tested and validated.

Abstract In this paper, an improved two‐step method is presented for the sensitivity analysis of vector network analyzer (VNA) S‐parameter measurements due to the non‐ideal line‐reflect‐match (LRM) calibration standards. This improved method is based on the indirect uncertainty propagation mechanism, which is especially suitable for the S‐parameter measurements applying the self‐calibration technique. To further simplify the formula derivation, the deviation matrices [δA] and [δB] are newly defined to represent the uncertainties of the T‐matrices of error boxes. With this definition, formulas for the deviations of device under test (DUT) S‐parameters can be concluded as functions of [δA] and [δB] in a concise form. Eventually, by solving only three linear combinations of the elements from [δA] and [δB], the sensitivity coefficients of DUT S‐parameters due to non‐ideal LRM can be conveniently deduced in an analytical form. Finally, experiments are performed to verify the proposed method.

The maximum electromagnetic coupling is directly related to the polarization angle of the incident field in the highaltitude electromagnetic pulse (HEMP) illumination test. Aimed at the linear system, this letter analyzed the test error of the maximum coupling corresponding to the change of the angel between the polarization direction and the direction of the equipment under test (EUT) in EMP illumination tests. Characterized by EM norm, quantization estimation formula of the maximum coupling test error under illuminations with EUT Rotations is deduced. The results show that the maximum measurement accuracy is the cosine of 1/2 of the maximum rotation angle of the EUTs. At last, a test scheme of 5 illuminations (with rotations of the EUT and the rotation angle of each rotation is 36∘) with 95% test accuracy of the maximum coupling of the method itself is recommended in this paper. The results can provide support for the design and evaluation of EM illumination test.

High-resolution beam telescopes for charged particle tracking are one of the most important and equally demanding infrastructure items at test beam facilities. The main purpose of beam telescopes is to provide precise reference track information of beam particles to measure the performance of a device under test (DUT). In this report the development of the ADENIUM beam telescope (ALPIDE sensor based DESY Next test beam Instrument) as a demonstrator and prototype for a next-generation beam telescope is presented. The ADENIUM beam telescope features up to six pixelated reference planes framed by plastic scintillators for triggering. ADENIUM is capable of replacing the currently used EUDET-type beam telescopes without impacting existing DUT implementations due to the integration of the telescope DAQ into EUDAQ2.In this report the concept and design of the ADENIUM telescope as well as its performance arediscussed. The telescope's pointing resolution is determined in different configurations. For anoptimal setup at a momentum of 5.6 GeV with an ALPIDE as DUT, a resolution better than3 μm has been extracted. No rate limitations have been observed at the DESY II test beam.

The Middle East Technical University Defocusing Beamline (METU-DBL) is designed to deliver protons with selectable kinetic energies between 15–30 MeV, and proton flux between 106–1010 protons/cm2/s, on a maximum 21.55 to 15.40 cm target region with a beam uniformity within ±6%, in accordance with the ESA ESCC No. 25100 specification for single event effects (SEEs) tests in the low energy range. The achieved high proton fluences, allow users to test space-grade materials; electronic circuits, ASICs, FPGAs, optical lenses, structural elements, and coating layers for LEO, GEO, and interplanetary missions.The total received dose on the Device-Under-Test (DUT) from secondary particles created during proton-material interactions at the first beam collimator and the beam dump never exceed 0.1% of the dose from primary protons. The METU-DBL is equiped with several measurement stations and services to the user teams. A secondary measurement station in a rotating drum that can hold multiple samples has been constructed next to the first collimator which provides neutrons for transmission experiments. At the target region, a robotic table is located, which provides mechanical and electrical mounting points to the samples and allows multiple samples to be tested in a row. A modular vacuum box can also be attached on the robotic table for any test that may require a vacuum environment. Power rails on the robotic table provide various outputs for the DUT. For the data acquisition, high-speed networking and a modular industrial PC are available at the target station. The design of the METU-DBL control software enables test users to integrate and optimize the data acquisition and controlling of the DUT.The beam properties at the target region are measured with the diamond, Timepix3, and fiber scintillator detectors mounted on the robotic table. With diamond and Timepix3 detectors, measurements are taken from the five different points (center and the four corners) of the test area to measure the proton flux and ensure that it is uniform across the full test area. Fiber scintillators on both axes (X and Y) scan the target area to cross-check the beam profile's uniformity. Secondary doses during the irradiation are measured by a Geiger-Müller tube sensitive to electrons and gammas above 0.1 MeV and by a neutron detector located at the entrance of the R&D room. The room cools down relatively fast after any irradiation (<1 hour).Accurate linear energy deposition rates and absorbed doses on the samples are calculated using MCNP6, FLUKA and Geant4 Monte Carlo simulations. Alanine dosimetry measurements that are calibrated against these simulations are also used to estimate the absorbed dose on the sample.