A method is presented for the measurement of shielding effectiveness planar materials with nonconducting surfaces such as carbon fiber composites. The overcomes edge termination problems by absorbing edge-diffracted energy. dynamic range up to 100 dB has been demonstrated over a frequency 1-8.5 GHz, depending on size sample under test. Comparison ASTM D4935 and nested reverberation measurements shows good agreement.

The inclusion of thin lossy material layers, such as carbon-based composites, is essential for many practical applications modeling the propagation electromagnetic energy through composite structures those found in vehicles and electronic equipment enclosures. Many existing schemes suffer problems late time instability, inaccuracy at low frequency (LF), and/or large computational costs. This paper presents a novel technique thin-layer materials finite-difference domain (FDTD) schemes, which...

Absorption by the contents of an equipment enclosure, particularly printed circuit boards (PCBs), affect enclosure's shielding performance. At high frequencies, this absorption can be quantified using angle arrival and polarization averaged cross-section (ACS). However, there is no available data on high-frequency characteristics modern PCBs. In study, we apply a reverberation chamber to determination average ACS large number PCBs taken from contemporary information communication technology...

We present broadband reverberation chamber measurements of the absorption cross section (ACS) human body averaged over all directions incidence and angles polarization. This frequency-dependent parameter characterizes interactions between enclosures reverberant environments such as aircraft cabins, is, therefore, important for determination overall Q-factor and, hence, field strength illuminating equipment inside enclosures. It also correlates directly with electromagnetic exposure occupants...

Average ACS can be measured in a reverberation chamber; however, the existing technique determines value that includes effects of radiation efficiencies antennas used measurement. Correcting for these necessitates further complex measurements. Here, we present theory an alternative measurement methodology using two nested or contiguous chambers which is free from errors caused by antennas. The new method based on theoretical average transmission cross sections (TCS) circular holes metal...

A measurement methodology for polarization and angle of incidence averaged electromagnetic absorption cross-section using a reverberation chamber is presented. The method optimized simultaneous rapid accurate determination average over the frequency range 1–15 GHz, making it suitable use in human exposure studies. typical time subject about 8 min with corresponding statistical uncertainty 3% measured cross-section. validated by comparing measurements on spherical phantom Mie series...

This paper describes a cost-efficient Intentional EMI Detection system and gives brief overview of the identification location being developed as part STRUCTURES project.

Average absorption cross section can be measured in a reverberation chamber with an uncertainty estimated from the number of independent samples transfer function taken during measurement. However, current model does not account loading effect object being or presence nonstochastic energy chamber, as characterized by Rician K-factor. Here, for cross-section measurements has been extended to include both these effects case stepped mechanical tuning paddle and frequency tuning. The formula...

The electromagnetic absorption cross-section (ACS) averaged over polarization and angle-of-incidence of 60 ungrounded adult subjects was measured at microwave frequencies 1–12 GHz in a reverberation chamber. Average ACS is important non-ionizing dosimetry exposure studies, closely related to the whole-body specific rate (WBSAR). average with statistical uncertainty less than 3% high frequency resolution for individuals range body shapes sizes allowing distribution WBSAR real population...

A simple model has been developed to characterize electromagnetic interference induced timing variations (jitter) in digital circuits. The is based on measurable switching parameters of logic gates, and requires no knowledge the internal workings a device. It correctly predicts not only dependence jitter amplitude, modulation depth frequency interfering signal, but also its statistical distribution. used calculate immunity level bit error rate synchronous circuit subjected radio...

The electromagnetic environment inside a shielding enclosure is affected by the absorption characteristics of contents, which should, therefore, be represented in measurements and simulations. At frequencies up to few gigahertz, lossy dielectric materials have previously been used as surrogates for printed circuit boards assessment, both experimentally However, no systematic methodology design these their calibration against real hardware at high has elucidated. In this paper, we show how...

The finite-difference time-domain (FDTD) method is a numerical technique that widely used to solve Maxwell's differential equations in the time domain [1]. Both space and are discretized. Space discretized into rectangular-shaped elements two-dimensional (2-D) or cuboid three-dimensional (3-D). Cuboid elements, where electric fields located on edges of magnetic normal faces, called Yee cells fundamental most FDTD methods [2]. By filling up problem with these cells, we obtain 3-D mesh,...

This paper describes the design and performance of a wide-band hybrid antenna suitable for use in reverberation chambers. The is characterised over frequency range 100 MHz to 25 GHz showing that it performs well above 200 although its ultimate highest operating has not been established.

Determination of the rate energy loss in a reverberation chamber is fundamental to many different measurements such as absorption cross section, antenna efficiency, radiated power, and shielding effectiveness. decay time constant domain by linear fitting power delay profile, rather than using frequency-domain quality-factor, has advantage being independent radiation efficiency antennas used measurement. However, determination regression suffers from several practical problems, including...

This paper reports the results of two experimental campaigns aimed at studying high-frequency response a raceway containing low voltage power, telephone, and Ethernet cables, to external electromagnetic field illumination. The was tested against HPEM transients inside gigahertz transverse (GTEM) cell low-power fields reverberation chamber (RC). high-power (HPEM) tests revealed that low-voltage power cables have greatest coupling under hyperband illumination, compared telephone cables. RC...

Cellular mobile phones may interfere with hospital equipment. We irradiated five representative pieces of equipment using simulated phone signals and frequencies. Two (an oximeter a syringe pump) were immune to electric fields up 40 V m-1. The most susceptible was physiological monitor which showed effects at 10 None the affected by that could be produced over one metre from 2 W phone.

This paper presents some thoughts on the meaning of shielding effectiveness (SE) for a real enclosure. It is demonstrated that conventional measurement SE value specific to particular and not necessarily representative enclosure in any practical situation, including different measurement. The an depends both contents, antenna effective transmission cross-section energy coupling mechanisms such as apertures, penetrations, seams diffusion through walls.

The reverberation chamber time constant quantifies how fast a loses its stored energy at different frequencies, which makes it very important parameter in many power related tests, such as the measurement of antenna efficiency, absorption cross section, and electromagnetic immunity test electronic devices. is usually obtained by doing regressions delay profile calculating gradient. But shape can sometimes be distorted band limited window function applied frequency domain. A non-linear curve...

Determination of the distribution electromagnetic energy inside electrically large enclosed spaces is important in many compatibility applications, such as certification aircraft and equipment shielding enclosures. The field environments contains a dominant diffuse component due to multiple randomizing reflections from enclosing surfaces. power balance technique has been widely applied analysis problems; however, it unable account for inhomogeneities that arise when absorption walls contents...

We take an initial look at hard single-event effects (SEEs) in power electronics and static random access memories (SRAMs) during space weather-induced extreme ground-level enhancement (GLE) events. show that there is a significant risk of failure silicon metal-oxide- semiconductor field-effect transistors (MOSFETs) insulated gate bipolar (IGBTs) ground level 10× February '56 GLE. If the devices are not derated, then we find 21% MOSFETs 14% IGBTs are, worst case, predicted to fail. The...

Shielding effectiveness (SE) is an important measure of how well enclosure reduces the electromagnetic (EM) field incident upon it. Commonly, when shielding stated it for case empty. Including contents such as printed circuit boards (PCBs) in will affect PCB absorbs EM energy. One technique determining much energy a to its absorption cross section (ACS) using reverberation chamber (RC). The measured ACS can be used predict inside power balance techniques. In this paper number PCBs are both...

The dielectric properties of biological tissues at radio and microwave frequencies are strongly correlated with tissue water content. Localized, in vivo measurement permittivity conductivity should therefore provide useful clinical information diseases involving abnormal hydration, such as lymphoedema. We have developed an open-geometry sensor for segmental hydration studies based on a flat cavity resonator operating 300 MHz, demonstrated that the changes its resonant frequency Q-factor were...

The interiors of mass transit vehicles act as pseudo-reverberant environments which are loaded by the bodies passengers. This study models broadband loading characteristics human body, first simulation with spherical approximations, then measurement nine subjects in a reverberation chamber. absorption cross-section is calculated from and unloaded transmission coefficients, compared to additionally full-wave simulations conducted during research into exposure. It found vary depending on...

The averaged absorption cross section (ACS) of a lossy object characterises its ability to capture power from diffused electromagnetic waves. ACS is very important in many EMC research areas such as indoor wireless channel modelling and human safety exposure study. measurement reverberation chamber can be achieved by measuring the rate loss time domain, however this technique requires dense frequency sampling for taking inverse Fourier transform, which consuming. A new scenario accelerates...

Thin-sheet models are essential to allow shielding effectiveness of composite enclosures and vehicles be modeled. Thin dispersive sheets often modeled using surface-impedance in finite-difference time-domain (FDTD) codes order deal efficiently with the multiscale nature overall structure. Such boundary conditions must applied collocated tangential electric magnetic fields on either side surface; this is usually done edges FDTD mesh cells at field sampling points. However, these edge-based...