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Showing papers in "IEEE Transactions on Electromagnetic Compatibility in 2016"


Journal ArticleDOI
TL;DR: In this article, a band-stop frequency selective surface (FSS) is proposed to provide effective shielding in X-band, with attenuation of at least 56 dB, and the proposed FSS provides 3-dB fractional bandwidth of 48% which is necessary to cover Xband.
Abstract: In this paper, a novel and miniaturized band-stop frequency selective surface (FSS) is presented. This FSS provides effective shielding in X-band, with attenuation of at least 56 dB. The proposed FSS provides 3-dB fractional bandwidth of 48% which is necessary to cover X-band. Moreover, the proposed design is polarization independent as it provides a stable frequency response at normal and oblique angles of incidences for both perpendicular TE and parallel TM wave modes. The copolarized and cross-polarized scattering parameter $S_{21}$ is analyzed at the selected band-stop/notch frequencies. More importantly, the proposed FSS is suitable for conformal applications and hence finds wider employability. A prototype of the proposed FSS is fabricated and tested. The measured results are in good agreement with the simulated results.

93 citations


Journal ArticleDOI
TL;DR: Based on the described principles, new devices can be designed which will be reliable, cheap, and radiation resistant due to the absence of any lumped components.
Abstract: The paper describes the ultra-wideband (UWB) pulse decomposition in simple printed structures aimed at low-cost and effective protection. The structure of an asymmetrical modal filter without resistors is considered, and the possibility of the attenuation by a factor of 55 is shown. Another structure—a turn of a meander line (ML)—is described, and the possibility of the attenuation by a factor of 2.5 is shown. Simulations without and with frequency-dependent losses in conductors and dielectrics are compared with experimental results. Based on the described principles, new devices can be designed which will be reliable, cheap, and radiation resistant due to the absence of any lumped components.

90 citations


Journal ArticleDOI
TL;DR: In this article, a low profile dual-band frequency selective surface (FSS) for shielding the GSM applications is presented, which contains the unit cell made of modified double square loop elements with paper as its substrate.
Abstract: A low profile dual-band frequency selective surface (FSS) for shielding the GSM applications is presented in this paper. The proposed FSS contains the unit cell made of modified double square loop elements with paper as its substrate. The overall thickness of the proposed FSS measures only 0.55 mm. The FSS offers band stop response at 930 and 1720 MHz with 18 dB shielding effectiveness for a bandwidth of 100 and 173 MHz, respectively, thus shielding the GSM signals. Additionally, the modified double square loop element-based FSS is symmetrical providing the advantage of polarization independency. It also exhibits angular stability up to 60° for both the horizontal polarized electric field (TE mode) and vertically polarized electric field (TM mode). A prototype of the proposed dual-band low profile FSS is fabricated. The simulation results are compared with the experimental results and are found to be in congruence with each other.

74 citations


Journal ArticleDOI
TL;DR: In this article, the authors provide step-by-step guidance on configuring and verifying chamber performance for over-the-air tests of single-antenna cellular wireless devices.
Abstract: Reverberation chambers provide a repeatable test environment for laboratory over-the-air testing and represent a viable solution for testing large-form-factor wireless devices. Such tests often involve “imperfect chamber” configurations in which the chamber is loaded with RF absorbing material. We provide step-by-step guidance on configuring and verifying chamber performance for over-the-air tests of single-antenna cellular wireless devices. We illustrate these methods with numerous examples, highlighting the tradeoffs in various chamber configurations. We conclude by calculating total radiated power and total isotropic sensitivity for a cellular-enabled wireless router and discuss methods for assessing uncertainty in estimates of these quantities.

68 citations


Journal ArticleDOI
TL;DR: In this paper, a theoretical analysis of the propagation effects of lightning electromagnetic fields over a mountainous terrain is presented, supported by simultaneous records of lightning currents and electric fields associated with upward negative lightning flashes to the instrumented Santis tower in Switzerland.
Abstract: In this paper, we present a theoretical analysis of the propagation effects of lightning electromagnetic fields over a mountainous terrain. The analysis is supported by experimental observations consisting of simultaneous records of lightning currents and electric fields associated with upward negative lightning flashes to the instrumented Santis tower in Switzerland. The propagation of lightning electromagnetic fields along the mountainous region around the Santis tower is simulated using a full-wave approach based on the finite-difference time-domain method and using the two-dimensional topographic map along the direct path between the tower and the field measurement station located at about 15 km from the tower. We show that, considering the real irregular terrain between the Santis tower and the field measurement station, both the waveshape and amplitude of the simulated electric fields associated with return strokes and fast initial continuous current pulses are in excellent agreement with the measured waveforms. On the other hand, the assumption of a flat ground results in a significant underestimation of the peak electric field. Finally, we discuss the sensitivity of the obtained results to the assumed values for the return stroke speed and the ground conductivity, the adopted return stroke model, as well as the presence of the building on which the sensors were located.

61 citations


Journal ArticleDOI
TL;DR: A method is illustrated that allows users to estimate the minimum number of stepped mode-stirring samples needed to ensure that the component of uncertainty due to spatial uniformity dominates for a given chamber setup, allowing the use of a simplified expression for uncertainty.
Abstract: We develop a significance test that determines whether the component of uncertainty due to the finite number of stepped mode-stirring samples or the component due to the lack of spatial uniformity dominates for a particular chamber setup and stirring sequence, as well as expressions for uncertainty for both cases. The significance test is illustrated with a measurement example comparing unloaded and loaded chambers for the measurement of a large-form-factor machine-to-machine device transmitting the wideband code-division-multiple-access (W-CDMA) protocol. Based on this example, we illustrate a method that allows users to estimate the minimum number of stepped mode-stirring samples needed to ensure that the component of uncertainty due to spatial uniformity dominates for a given chamber setup, allowing the use of a simplified expression for uncertainty.

56 citations


Journal ArticleDOI
TL;DR: In this paper, a decomposition method based on reciprocity theory is proposed to estimate the coupling from the noise source to the victim antennas, which is validated by full-wave simulations and measurements of a simple printed circuit board.
Abstract: In modern electronic products, the noise from high-speed digital parts is likely to interfere with nearby receivers, causing radio-frequency interference (RFI) issues. In this paper, the equivalent dipole-moment models and a decomposition method based on reciprocity theory are proposed being used together to estimate the coupling from the noise source to the victim antennas. The dipole-moment models are extracted from the near fields of the noise source by solving the inverse problem. The tangential electromagnetic fields on a Huygens's surface, which enclose the victim antenna, can be calculated from these equivalent dipole-moment models. Then, the victim antenna only is treated as a radiator. The tangential electromagnetic fields from the radiating antenna on the same Huygens's surface can be obtained. With these two groups of the fields on the Huygens's surface, the reciprocity theory is applied to estimate the coupling from the noise source to the victim antenna. This method is validated by full-wave simulations and measurements of a simple printed circuit board. The proposed method provides convenience to estimate RFI issues in the early design stage and saves the time of RFI simulation and measurements.

54 citations


Journal ArticleDOI
Tao Tao1, Zhihua Zhao1, Weiming Ma1, Qijun Pan1, Anqi Hu1 
TL;DR: In this article, the authors proposed a new PCB Rogowski coil with symmetric double-printed imprints and returning turn to gain better precision and performance, and the mutual inductance between the coil and the primary conductor was chosen as the sensitivity parameter to contrastively analyze the anti-interference property of three coils.
Abstract: Rogowski coil is used as a current transducer in complex electromagnetic environment, whose anti-interference property bears on the accuracy of the current measurement. Based on the ordinal straight-coupled foils of the current PCB Rogowski coil, this paper proposes a newly designed PCB Rogowski coil with symmetrical double-printed imprints and returning turn to gain better precision and performance. The mutual inductance between the coil and the primary conductor is chosen as the sensitivity parameter to contrastively analyze the anti-interference property of three coils, including the ordinary straight-coupled coil, the symmetrically printed coil with or without returning turn. The calculation and measurement of mutual inductance have been made under different disturbed conditions, such as the eccentricity from axis of the primary conductor and the influence of external parallel and perpendicular currents. The results indicate that the newly designed PCB Rogowski coil with symmetric imprints and returning turn is good in compatibility, strong in anti-interference property, and also accurate and steady in mutual inductance. Therefore, it is suitably applied as the sensing head of current measurement in the complex stray electromagnetic fields.

43 citations


Journal ArticleDOI
TL;DR: In this paper, a combination of techniques that includes empirical mode decomposition and transient mode decomposition is used to separate the main components of complex electromagnetic disturbances, which is useful to gain insights of the process that generates the interference.
Abstract: Electromagnetic interferences are potentially very complex signals formed by the superposition of transient (broadband) and continuous wave (narrowband) components with significant randomness in both amplitude and phase. Decomposing the electromagnetic interference measured in the time domain into a set of intrinsic mode functions is useful to gain insights of the process that generates the interference. Evaluating the intrinsic mode functions contributes to improving the measurement capabilities of the time-domain electromagnetic emissions measurement systems based on the general-purpose oscilloscopes. In this paper, a combination of techniques that includes empirical mode decomposition and transient mode decomposition is used to separate the main components of complex electromagnetic disturbances. This approach requires no prior information on the spectral content of the measured EMI and it does not perform a domain transformation. Examples of electromagnetic interference decomposition verify the effectiveness and the accuracy of the proposed approach. Finally, a discussion on the advantages, practical applications, limitations, and drawbacks of the described techniques is addressed.

42 citations


Journal ArticleDOI
TL;DR: In this paper, a novel optimization design method for circuit analog absorbers consisting of resistor-loaded square-loop arrays is proposed, which is applicable for multilayered absorbers with printed single or double SLAs on each layer.
Abstract: This paper proposes a novel optimization design method for circuit analog absorbers consisting of resistor-loaded square-loop arrays. First, new precise equivalent circuit models (ECMs) for square-loop-array-based absorbers are derived through the synthetic asymptote method. The presented models are applicable for multilayered absorber with printed single or double SLAs on each layer. Then, the combination of this ECM and conventional genetic algorithm (GA) is proposed and provided a fast and efficient way to design broadband and low-profile SLA absorbers. For demonstration, four absorbers are designed and optimized. Finally, the agreement between the simulated and measured reflection coefficients indicates the validity of the presented method.

42 citations


Journal ArticleDOI
TL;DR: In this paper, an emission source microscopy (ESM) technique derived from synthetic aperture radar (SAR) was used to localize radiating sources on a complex PCB.
Abstract: For large, complex systems with multiple sources at the same frequency, localizing the sources of radiation often proves difficult. This paper presents an emission source microscopy (ESM) technique derived from synthetic aperture radar (SAR) to localize radiating sources on a PCB. Near-field scanning provides limited information about the components contributing to far-field radiation. This paper presents the source localization methodology, supported by simulation and measurement results. After localizing the sources, the far-field contribution and the total radiated power from each individual source can be estimated. The results show that the proposed method can distinguish between multiple radiating sources on a complex PCB.

Journal ArticleDOI
TL;DR: In this article, the authors present a field prediction method, which combines a measured CM current distribution with numerical computations for the radiated fields in the frequency range of 30-1000 MHz.
Abstract: According to automotive standard CISPR 25, electronic components or modules are required to be connected to a specific test cable bundle in order to evaluate the radiated emissions. In the absorber-lined shielded enclosure (ALSE) method, also called the antenna method, the cable bundle is often the dominant radiation structure due to its length. This measurement method requires a large anechoic chamber, but often, it is only the impact of the test cable bundle's common-mode (CM) current distribution that is measured. Since the current distribution can be measured easily with current clamps, and with much lower demands to the environment, it is advantageous that the level of radiated fields can be estimated from the measured current distribution. This paper presents a field prediction method, which combines a measured CM current distribution with numerical computations for the radiated fields in the frequency range of 30–1000 MHz. Applicability is discussed based on several complex test cases. Three major problems had to be solved. First, appropriate current phase measurement methods had to be developed since the current amplitudes are not sufficient for estimating the electric fields. Second, a CM radiation model of a cable bundle had to be found. Third, in order to get comparable data for the ALSE test environment, a method had to be developed that could take this influence into account. Different solution approaches are examined here for the problems mentioned above.

Journal ArticleDOI
TL;DR: In this paper, an improved circuit model for the prediction of the shielding effectiveness and resonances of an enclosure with apertures is presented, where an aperture position factor is introduced to deal with an off-centered aperture.
Abstract: This paper presents an improved circuit model for the prediction of the shielding effectiveness and resonances of an enclosure with apertures. In the model, an aperture position factor is introduced to deal with an off-centered aperture. The factor considers the effect of higher order modes, and is thus more accurate than those considering the effect of TE10 mode only or considering the effect of higher order modes incorrectly. Moreover, because of the factor, multiple apertures are not required to be similar and can have arbitrary distribution. Three orthogonal components of voltage response are considered based on the waveguide theory; therefore, higher order modes including ${\rm TM}_{\rm mn0}$ modes can be predicted precisely, which are not possible with those previous circuit models derived from Robinson's model. Besides, monitor point can locate anywhere within enclosure and aperture can have arbitrary length–width ratio. The presented model provides a more accurate means for the prediction of the shielding effectiveness and higher order modes of an enclosure with arbitrarily positioned apertures over a wide frequency range compared with other existing circuit models, and costs much less solution time and fewer computing resources than traditional numerical methods. The validity of the presented model is verified by the transmission line matrix method.

Journal ArticleDOI
TL;DR: In this article, an iterative and adaptive perturbation technique for the analysis of non-uniform transmission lines is presented, where perturbations of increasing order are computed iteratively starting from the solution of the unperturbed line.
Abstract: This paper presents an iterative and adaptive perturbation technique for the analysis of nonuniform transmission lines. Place-dependent variations of the per-unit-length parameters are interpreted as perturbations with respect to their average values along the line. This allows casting the governing equations for the corresponding perturbations of the voltages and currents as those of a uniform transmission line with distributed sources. Therefore, standard transmission line theory is used to calculate these perturbation terms. Specifically, perturbations of increasing order are computed iteratively starting from the solution of the unperturbed line. The accuracy is adaptively adjusted by setting a threshold on the convergence of the solution. The algorithm turns out to be simple to implement and very accurate, yet faster than traditional approaches based on the discretization of the line into uniform sections. The technique is validated through the analysis of several nonuniform transmission line structures of relevance in EMC applications, namely uniformly and nonuniformly twisted wire pairs as well as a cable bundle with lacing cords.

Journal ArticleDOI
TL;DR: In this article, the authors proposed a method for the extraction of the CM impedance of an inverter-fed induction motor, which does not require laborious modeling of the motor or cable, and the extraction process is much simpler and easier.
Abstract: In a variable speed drive (VSD) system, high-frequency switching of power devices will cause large common-mode (CM) voltage during operation. While the CM voltage acts on the parasitic capacitance of the system, it will generate serious CM current on the motor side. It is necessary to model the VSD system so as to analyze and forecast the CM current theoretically. However, an essential condition of modeling CM current is to extract the CM impedance on the motor side of the system. In this paper, a novel extraction method for the CM impedance of an inverter-fed induction motor is proposed. First of all, time-domain waveforms of the CM voltage and current on the motor side of the VSD system are measured, and then mathematical calculations are performed to obtain the spectrum characteristics of the CM impedance on the motor side of the system. Compared to the traditional extraction methods of the impedance parameter by an impedance measurement or numerical calculation, the method proposed in this paper does not require laborious modeling of the motor or cable, and the extraction process is much simpler and easier. Moreover, in traditional methods, the motor impedance parameters are usually obtained in a nonworking state, while the proposed extraction method can be conducted in working state. Thus, the CM impedance extracted by the proposed method will be more accurate. Through comparing measurement and the simulation results of the CM current on motor side, the proposed CM impedance extraction method for an inverter-fed induction motor is validated.

Journal ArticleDOI
TL;DR: This paper demonstrates a very simple and highly accurate expression of power supply-induced jitter sensitivity transfer function for CMOS buffer chain.
Abstract: This paper demonstrates a very simple and highly accurate expression of power supply-induced jitter sensitivity transfer function for CMOS buffer chain. The transfer function is mainly a function of the maximum and minimum propagation delay of the buffer chain. The function can be easily obtained and used in jitter budget calculation.

Journal ArticleDOI
TL;DR: In this article, a methodology for modeling the power delivery network from the voltage regulator module to the pins of a high pin count integrated circuit on a printed circuit board (PCB) is presented.
Abstract: A methodology for modeling the power delivery network from the voltage regulator module to the pins of a high pin count integrated circuit on a printed circuit board (PCB) is presented. The proposed model is based on inductance extraction from first principle formulation of a cavity formed by parallel metal planes. Circuit reduction is used to practically realize the model for a production level, complex, multilayer PCBs. The lumped element model is compatible with SPICE-type simulators. The resulting model has a relatively simple circuit topology. The model is corroborated with microprobing measurements up to a few gigahertz. The model can be used for a wide range of geometry variations in a power integrity analysis, including complex power/ground stack up, various numbers of decoupling capacitors with arbitrary locations, numerous IC power pins and IC power/ground return via layouts, as well as hundreds of ground return vias.

Journal ArticleDOI
TL;DR: In this paper, a common-mode filter (CMF) based on the silicon interposer process with through-silicon vias (TSV) is proposed to improve the electromagnetic compatibility.
Abstract: In this paper, the radiation of signaling channel that may lead to noise coupling, electromagnetic interference or radio-frequency interference problems in three-dimensional integrated circuits (3-D ICs) is discussed. To improve the electromagnetic compatibility, a common-mode filter (CMF) based on the silicon interposer process with through-silicon vias (TSV) is proposed. A differential second-order T-model circuit for transmission lines with a common inductance is proposed to characterize and design the stopband and corresponding two transmission zeros for common mode (CM). Codesigned with through-silicon vias, this TSV-based CMF (TSV-CMF) is implemented in a cost-efficient interposer process and the measurement results match well to both the equivalent circuit model and full-wave simulation. It is measured that the differential bandwidth of the TSV-CMF can reach 25 GHz and CM stopband is around 15 GHz with 20% fractional bandwidth. In addition, the suppressing frequency and bandwidth can be easily altered and improved by using more stacked chips on the interposer.

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a new tightly coupled handheld resonant magnetic field (HH-RMF) charger operating at 20 kHz with low EMF and high efficiency, using a guided magnetic flux in resonance structure.
Abstract: Wireless power transfer (WPT) technology is an electrically safe and convenient method of charging batteries. WPT technology allows elimination of exposed contacts, which can cause direct electrocution of human. In spite of the great advantages, the WPT system inevitably generates strong electromagnetic fields (EMFs), causing interference on the nearby electrical devices as well as harmful influence on human health. Therefore, it is important to satisfy EMF guidelines and reduce leakage magnetic field harmonics in WPT system. For the first time, in this paper, we propose a new tightly coupled handheld resonant magnetic field (HH-RMF) charger operating at 20 kHz with low EMF and high efficiency. Using a guided magnetic flux in resonance structure, 64.5 mG of EMF is reduced compared to the conventional inductive charger at a distance of 200 mm from edge of the core. In addition to the electromagnetic interference (EMI) reduction, the isolation inductor scheme is proposed as an EMI reduction method. Through a series of measurements, we experimentally verified that the proposed HH-RMF charger complies with the regulations published by the International Commission on Non-Ionizing Radiation Protection in 1998. The proposed HH-RMF charger with the isolation inductor scheme successfully reduces the third harmonic of the Tx and Rx currents by 23.4 and 11.8 dBμA, respectively. Furthermore, the third and fifth magnetic field harmonics reduce by 1.38 and 0.67 mG, respectively. The coil-to-coil power transfer efficiency and total system power transfer efficiency of the proposed structure are maintained at over 98% and 84%, respectively.

Journal ArticleDOI
TL;DR: In this article, the authors applied a reverberation chamber to the determination of the average ACS of a large number of printed circuit boards taken from contemporary information and communication technology (ICT) equipment to provide a unique and comprehensive dataset.
Abstract: Absorption by the contents of an equipment enclosure, particularly printed circuit boards (PCBs), affect the enclosure's shielding performance. At high frequencies, this absorption can be quantified using the angle of arrival and polarization averaged absorption cross-section (ACS). However, there is no available data on the high-frequency absorption characteristics of modern PCBs. In this study, we apply a reverberation chamber to the determination of the average ACS of a large number of PCBs taken from contemporary information and communication technology (ICT) equipment to provide a unique and comprehensive dataset. The ACS was found to range from 4 × 10−4–10−2 m2 from 2–20 GHz and different classes of PCB could be identified according to their surface characteristics. The “shadowing effect” of densely packed PCBs was also quantified for a subset of the PCBs. It was found that the ACS of a PCB in the stack was reduced by 20%–40% compared to its value when isolated. By way of a review of the general power balance analysis of an electrically large populated equipment enclosure in an external environment, we show how the acquired data will be useful for future qualification methodologies for ICT enclosures and PCBs.

Journal ArticleDOI
TL;DR: In this article, an iteration-free-phase retrieval method for directive radiators based on field amplitudes on two closely separated observation planes is proposed, where the Huygens principle and the image theory are applied on the first observation plane, and the complex-valued field quantities on the two observation planes are related through the radiation matrix.
Abstract: This letter proposes an iteration-free-phase retrieval method for directive radiators based on field amplitudes on two closely separated observation planes. Due to the small separation, local optimization suffers from converging to local minima, and global optimization consumes long CPU time. In the proposed method, the Huygens’ principle and the image theory are applied on the first observation plane, and the complex-valued field quantities on the two observation planes are related through the radiation matrix. The radiation matrix is then scaled by the field amplitudes on the two observation planes. It is shown that, if the phase difference between the two observation planes is relatively uniform, an eigenvector of the scaled radiation matrix constitutes a solution to the phase retrieval problem, which achieves iteration-free-phase retrieval. The problem of convergence to local minima is thus avoided. Simulation results are presented to show the effectiveness of the proposed method.

Journal ArticleDOI
TL;DR: In this paper, a frequency-tunable resonant magnetic field probe is designed for near-field scanning applications for the radio frequency interference studies, which is achieved by using a varactor diode providing the required capacitance and the parasitic inductance of a magnetic loop (i.e., a parallel LC circuit).
Abstract: A frequency-tunable resonant magnetic field probe is designed for near-field scanning applications for the radio frequency interference studies. Tunable resonance is achieved by using a varactor diode providing the required capacitance and the parasitic inductance of a magnetic loop (i.e., a parallel LC circuit). An equivalent circuit model for the probe is described, analyzed, and used for designing the probe for achieving maximum sensitivity. The resonance frequency of the designed probe is tunable in the frequency range of 900–2260 MHz that covers multiple radio bands, such as the GSM900, UMTS, and GPS bands. The sensitivity of the probe at the resonance frequency is about 7–9 dB higher than that of an equivalently sized broadband magnetic field probe throughout the tunable frequency range. The measured frequency response and sensitivity over a microstrip trace using the fabricated probe shows good agreement with the simulated results of the equivalent circuit model and the full-wave simulation model.

Journal ArticleDOI
TL;DR: In this paper, the authors applied the finite-difference time-domain (FDTD) method to the lightning surge analysis of an air-insulated substation, and compared the breakdown characteristics calculated using the proposed techniques with measured results for validation.
Abstract: The operating voltages of low-voltage control circuits in power plants and substations have decreased with the installation of digital control equipment. This increases the susceptibility of control equipment to abnormal surges, which arise mainly from lightning. To protect control equipment from lightning, it is necessary to predict lightning surges invading power plants and substations and design effective lightning protection methodologies. Compared with conventional simulation techniques based on circuit theory, full-wave numerical approaches are advantageous in handling three-dimensional structures such as transmission line towers, grounding structures, nonhorizontal wires, such as incoming power lines to power plants and substations, and lightning-induced effects. In this study, to apply the finite-difference time-domain (FDTD) method to the lightning surge analysis of an air-insulated substation, we first propose techniques for simulating the nonlinear breakdown characteristics of short-air-gap arcing horns and transmission line surge arresters installed in 77 kV transmission lines for FDTD-based surge simulations, and compare the breakdown characteristics calculated using the proposed techniques with measured results for validation. Second, as an example of the application of the proposed techniques to practical surge analysis, it is confirmed that we can reproduce the measured results of lightning surges invading a 77 kV air-insulated substation in the case of a direct lightning strike to its nearby transmission line tower by taking into account lightning-induced voltages arising from the lightning current flowing through the lightning channel and transmission line tower, which are commonly ignored in conventional circuit-theory-based simulations, multiphase back-flashover phenomena, and the effect of applied AC voltages.

Journal ArticleDOI
TL;DR: In this paper, various approximate methods for radio frequency electromagnetic field compliance assessments of radio base station products utilizing these antenna arrays are investigated with the focus on front compliance distances. But the results show that accurate compliance boundary dimensions may be obtained using a field-combining procedure of assessment results for a centrally placed element.
Abstract: The importance of antenna arrays with beam-forming capability is expected to increase in future mobile communication systems with the ongoing development of new radio access technologies involving higher frequency bands and massive MIMO concepts. In this paper, various approximate methods for radio frequency electromagnetic field compliance assessments of radio base station products utilizing these antenna arrays are investigated with the focus on front compliance distances. For electrically large arrays, the results show that accurate compliance boundary dimensions may be obtained using a field-combining procedure of assessment results for a centrally placed element. For smaller arrays, an overall improvement in accuracy is possible by complementing the center element solution with results for a handful of selected edge and corner elements to better characterize the array behavior. Compared with a general and straightforward approach based on field combining of embedded assessment results for each element, the approximate methods allow for significant reductions of the total assessment time.

Journal ArticleDOI
TL;DR: In this article, a novel structure for suppressing simultaneous switching noise is proposed based on the coplanar electromagnetic bandgap (EBG) power plane, which is designed on the basis of periodic L-bridge which is inserted by a small Lbridge cell with windmill-shaped slits where the power port is located.
Abstract: In the paper, a novel structure for suppressing simultaneous switching noise is proposed based on the coplanar electromagnetic bandgap (EBG) power plane. The proposed EBG structure is designed on the basis of periodic L-bridge which is inserted by a small L-bridge cell with windmill-shaped slits where the power port is located. Simulation and measurement results show that the presented structure possesses a wide stop band ranging from 510 MHz to 10.35 GHz at −40 dB suppression of the bandgap depth. Then, the IR drop and the dc resistance are accurately investigated by the simulation software of CST. Finally, time-domain simulation results show that the structure in high-speed circuit is met with signal integrity.

Journal ArticleDOI
TL;DR: In this article, the authors proposed an alternative measurement methodology using two nested or contiguous reverberation chambers which is free from errors caused by the radiation efficiencies of the antennas, which is based on the theoretical average transmission cross sections of circular holes in a metal plate between the two chambers.
Abstract: Average ACS can be measured in a reverberation chamber; however, the existing technique determines a value that includes the effects of the radiation efficiencies of the antennas used in the measurement. Correcting for these necessitates further complex measurements. Here, we present the theory of an alternative measurement methodology using two nested or contiguous reverberation chambers which is free from errors caused by the radiation efficiencies of the antennas. The new method is based on the theoretical average transmission cross sections (TCS) of circular holes in a metal plate between the two chambers. In fact, the method can be viewed as an accurate transfer calibration measurement between TCS and ACS that is independent of both the chamber and antenna characteristics. Further, since the existing method of measuring ACS includes the effects of the radiation efficiencies of the antennas, a comparison of the ACS of a reference object, measured using both the existing and new methods, also provides an alternative method of determining radiation antenna efficiency. Measurement uncertainties for both alternative measurement methods—ACS and antenna radiation efficiency—are also derived.

Journal ArticleDOI
TL;DR: A fast and accurate total isotropic sensitivity testing method for wireless user equipment based on radiated sensitivity measurement and received signal strength (RSS) reporting is proposed in this paper.
Abstract: A fast and accurate total isotropic sensitivity (TIS) testing method for wireless user equipment based on radiated sensitivity measurement and received signal strength (RSS) reporting is proposed in this paper. Innovative techniques for avoiding the effects of RSS reporting errors on TIS accuracy and reducing the total TIS measurement time are presented and incorporated into the testing procedures. The proposed method is suitable for receiver sensitivity testing of single input, single output radio systems having RSS reporting such as cellular communication, WiFi, and Bluetooth systems.

Journal ArticleDOI
TL;DR: In this paper, an original theory on negative group-delay (NGD) topology of parallel interconnect line (PIL) was described, which consists of a fully distributed circuit without lossy lumped components.
Abstract: This paper describes an original theory on negative group-delay (NGD) topology of parallel interconnect line (PIL). The proposed topology consists of a fully distributed circuit without lossy lumped components. The PIL voltage transfer function (VTF) is derived from the equivalent transfer matrix. Then, the frequency-dependent expressions of the PIL VTF gain and group delay are extracted. It is shown that the NGD phenomenon can be generated when the PIL is lossy and presenting different electrical lengths. The fundamental NGD properties versus the PIL parameters are established. This NGD concept was validated with implemented two microstrip PIL circuits. The theoretical and measured group-delay behaviors are well correlated. As expected theoretically, the demonstrator with identical 50-Ω characteristic impedance enables to generate NGD of about −4 ns at 1.75 GHz under −5-dB attenuation. Similarly, an −2.1-ns NGD level at 1.99 GHz was occurred with the other 50 Ω/117 Ω characteristic impedances NGD circuit under only −2.5-dB attenuation loss. The NGD function can be potentially used for the microwave signal integrity improvement.

Journal ArticleDOI
TL;DR: In this article, it was shown that the modified image (or reflection coefficient) method in EFIE-based solutions (e.g., the Pocklington equation) leads to a large error (larger than 20%) in the low-frequency range for the computation of the current distribution in conductors longer than 10m.
Abstract: It is common practice in the engineering analysis process to use an approximate image method for the computation of the current in buried horizontal conductors (in the literature, this is often referred to as the “modified image” or “reflection coefficient” method). According to this approach, the earth/air interface is replaced by a positive mirror image of the charge and current in the conductor, and its field is multiplied by a suitable reflection coefficient. Different opinions on the validity of this approximation have been expressed in published debates, but more systematic analysis of the error introduced by this approach is not available in the literature. To establish the amount of error, we compare the computation results of the image model with the rigorous Sommerfeld integral method for a wide range of parameters. Contrary to widespread opinion, our results suggest that the modified image (or reflection coefficient) method in EFIE-based solutions (e.g., the Pocklington equation) leads to a large error (larger than 20%) in the low-frequency range for the computation of the current distribution in conductors longer than 10 m. In such a case, MPIE-based methods are preferred for use to achieve a smaller error (approximately 5%). Guidelines for the application of image models related to the conductor, earth and excitation parameters, upper frequency limit, and modeling method are presented.

Journal ArticleDOI
TL;DR: The full-wave simulation method is adopted to calculate the electric field and numerical integration method is applied to solve the BLT equation, which simplifies the modeling process significantly and possesses better efficiency.
Abstract: Conventional analytical and numerical approaches are inefficient for the analysis of electromagnetic (EM) coupling effect on a printed circuit board (PCB) in complicated electric systems. This paper develops a hybrid method based on the combination of electromagnetic topology and analytical method or full-wave simulation. A coupling mechanism of PCB in a nested shielding enclosure is established, and the EM interactions from exterior fields to interior PCB are determined by the way of conductive and radiation coupling interference. The total load disturbance voltage of PCB trace is obtained by solving the BLT equation of the two interference paths. In this paper, the full-wave simulation method is adopted to calculate the electric field and numerical integration method is applied to solve the BLT equation. The results of the proposed method are in good agreement with the result of a commercial full-wave tool, which confirms its validity. Compared to numerical simulation, the proposed method simplifies the modeling process significantly and possesses better efficiency.