Javad Meiguni - Academia.edu (original) (raw)

Papers by Javad Meiguni

Journal of The Textile Institute, Apr 10, 2023

IEEE Transactions on Electromagnetic Compatibility, Aug 1, 2020

The ability to predict the electric and magnetic fields generated by a component can solve many i... more The ability to predict the electric and magnetic fields generated by a component can solve many in-system interference problems before they occur. In this article, methods are presented to predict the high-frequency near electric and magnetic fields from a component using a method of moment approach. The current representation is estimated from a near electric-field scan by solving the electric field integral equation. The reconstruction method was validated with measurements of a test board containing a buffer integrated circuit. The current representation was shown to accurately predict fields at locations both above and to the side of the buffer with less than a 3.5-dB average error. Here, a near-field scan was only performed on a flat plane above the emitter and was used to predict sources to the side of the emitter. To accurately predict fields to the side of the emitter, the current representation must be defined on a surface between the emitter and the prediction location. An error analysis was performed to understand the impact of scan plane parameters, such as the size of the scan plane, the size of the current representation, and the relative distance between the current representation and the estimated fields on prediction accuracy.

IEEE Transactions on Electromagnetic Compatibility

IEEE Transactions on Antennas and Propagation

IEEE Transactions on Electromagnetic Compatibility

IEEE Access

An inverse method of moments (MoM) approach is developed to estimate the equivalent electric/magn... more An inverse method of moments (MoM) approach is developed to estimate the equivalent electric/magnetic current sources to predict radio frequency interference (RFI) in electronic devices. The proposed method is designed to reconstruct the noise sources in electronic devices containing multiple radiating elements by using a finite metal object carrying electric surface currents. The surface current elements are further applied to calculate the electromagnetic fields on arbitrary observation planes near the device under test (DUT). The method is validated through numerical simulation examples, including electrictype CPU noise, magnetic-type non-planar HDMI connector noise, printed circuit board (PCB) with Wi-Fi and PIFA antennas, and heat sink embedded in the DUT. The results confirm less than 0.4 dB difference in the predicted pattern at the antenna operating frequency when a triangular segmentation is applied in the vicinity of the noise source area, and the equivalent surface current is calculated at the edges of the Rao-Wilton-Glisson (RWG) meshes. The proposed method is a promising 'source reconstruction' candidate for predicting the near-field radiation characteristics of electronic devices with multiple peaks and nulls in the near-field radiation pattern. The method helps estimate the level of RFI by summing up the contributions of all the dipoles of the equivalent noise source derived by solving forward and inverse problems. The RFI results based on the inverse MoM approach are validated by comparing them with those obtained from CST simulation, and good agreement is achieved between the two.

Progress In Electromagnetics Research Letters, 2022

This letter proposes a novel analysis and design method of a continuously adjustable bandpass com... more This letter proposes a novel analysis and design method of a continuously adjustable bandpass combline filter. It investigates the feedline design specifications and introduces an external quality factor (Qext) tuning structure to achieve a constant fractional bandwidth over 60% tuning bandwidth. The design approach allows to determine the optimum feedline structure for the filter and is verified by full-wave simulation and measurement. The results show a constant fractional bandwidth of 4.5% over the entire operating frequency range between 225–400MHz.

IEEE Transactions on Electromagnetic Compatibility

In this paper, a new leaky wave antenna (LWA) based on complementary split- ring resonators (CSRR... more In this paper, a new leaky wave antenna (LWA) based on complementary split- ring resonators (CSRRs) and slot line are proposed. Efiects of CSRRs on beam scanning in a composite right/left handed (CRLH) LWA based on split-ring resonators (SRRs) are investigated. Actually, the efiects of these structures on the scan angles have been compared. The commercial Ansoft HFSS software is adopted for the simulations. The proposed LWA is analyzed in S and C band frequency, and the results reveal that the CSRR improves the gain in backward leaky wave radiation. The CSRR-LWA just scans the negative angles. Furthermore, the simulation results demonstrate the potential of the SRR-LWA to radiate from backward to forward scanning angles. As a result this miniaturized CSRR-LWA main beam can scan the space for C-band from i115 to i170 degree in phi = 0 (deg) plane. In the other word, the CSRR-LWA only scans in the negative ranges of theta, but SRR-LWA scans the space from +94 - to +156 - in positive r...

International Journal of Microwave and Wireless Technologies, 2018

In this paper, two new feed network designs for single layer and double layer slotted waveguide a... more In this paper, two new feed network designs for single layer and double layer slotted waveguide array antennas are presented. A microstrip to substrate integrated waveguide transition is applied to the single layer antenna. The aperture coupling mechanism is used in order to find the optimum feed network for double-layer structure and to obtain stable radiation characteristics over the frequency band. The prototypes of the proposed antennas have been fabricated and tested. The measured results were compared very well with the simulation results obtained from CST microwave studio and showed low side lobe level at the center frequency of 11.5 GHz for the low-profile 4-channel slotted waveguide arrays.

Journal of Information Systems and Telecommunication (JIST), Sep 1, 2013

Theory and experiment of a spherical probe-fed conformal antenna with a parasitic element mounted... more Theory and experiment of a spherical probe-fed conformal antenna with a parasitic element mounted on a spherical multilayer structure are presented in this paper. Rigorous mathematical Method of Moments (MoMs) for analyzing various radiating spherical structures is presented in this paper by using Dyadic Green's Functions (DGFs) in conjunction with Mixed Potential Integral Equation (MPIE) formulation. Linear Rao-Wilton-Glisson (RWG) triangular basis functions are applied in MPIE formulation. Current distributions on coaxial probe and conformal radiating elements are computed by using spatial domain Dyadic Green's Function (DGF) and its asymptotic approximation. A prototype of such an antenna is fabricated and tested. The effect of the parasitic element on the input impedance and radiation patterns of the antenna is investigated. It is shown that the antenna characteristics are improved significantly with the presence of the conducting parasitic element. Good agreement is achieved between the results obtained from the proposed methods and the measurement results.

2022 IEEE International Symposium on Electromagnetic Compatibility & Signal/Power Integrity (EMCSI)

2015 23rd Iranian Conference on Electrical Engineering, 2015

Presented is an ultra-broadband stripline directional coupler with significant improvement in its... more Presented is an ultra-broadband stripline directional coupler with significant improvement in its directivity parameter which is of interest in many measurement applications. The main focus of this paper is on the influence of using shunt stubs as capacitance compensators to improve specifications of wideband directional couplers. This improvement is performed on a two-layer non-uniform line directional coupler working in 2-18 GHz band. Experimental results, for various classes of wideband stripline couplers loaded with these stubs, exhibit remarkable improvement in the directivity parameter.

2 This paper presents two miniaturized slow wave structures in microstrip leaky-wave antennas (ML... more 2 This paper presents two miniaturized slow wave structures in microstrip leaky-wave antennas (MLWAs) which operate about 8 GHz. The effects of these structures on the scan angles have been compared in the paper. The designed interdigital capacitors and folded-back line have been investigated with ADS Momentum software. It has been shown that the interdigital capacitors (IDCs) yield to a broad scan angles from +53 to-74 degree, while the folded-back line inductor scans only the positive angles. Index Terms-leaky-wave antenna (LWA), scan angle, slow wave structure, periodic structure.

2021 IEEE International Joint EMC/SI/PI and EMC Europe Symposium, 2021

An IC protected by a transient voltage suppression (TVS) diode may fail if the TVS device does no... more An IC protected by a transient voltage suppression (TVS) diode may fail if the TVS device does not turn on or does not turn on quickly enough, causing the IC to take the full brunt of the ESD event. System Efficient ESD Design (SEED) simulation can help predict when the TVS will turn on and the level of ESD stress seen by the IC. In the following paper, models are developed to predict the voltage and current through a TVS and on-chip protection diodes connected to a USB cable when an ESD gun discharges to a pin at the end of the cable. A hybrid simulation methodology is proposed, which uses a full-wave model of the ESD gun, cable, and enclosure combined with the ESD protection devices and test board's circuit-level models. The response of the ESD protection is studied in simulation and measurement for a variety of cable configurations. Simulations of the voltage and current waveforms match measurements 24-35%. The total charge delivered to the on-chip diode as a function of ESD ...

Journal of Modeling in Engineering, 2016

A fourth-degree Substrate Integrated Waveguide (SIW) crossed coupled band pass filter for WLAN ba... more A fourth-degree Substrate Integrated Waveguide (SIW) crossed coupled band pass filter for WLAN band is designed by using a new negative coupling structure. It consists of two U shape microstrip lines on top and bottom planes with via holes at the center of them. This paper investigates the phase characteristics of negative and positive coupling structures and their effects. The design, fabrication and testing processes of the proposed filter are presented. The measured results seem to be consistent with the results obtained from simulator packages.

2018 IEEE International Reliability Physics Symposium (IRPS), 2018

This paper introduces the application of system-efficient ESD design (SEED) to ESD-induced pulses... more This paper introduces the application of system-efficient ESD design (SEED) to ESD-induced pulses that are typical for system-level ESD. Emphasis is given to USB connectors because it has been shown that discharges to the connector shell will not lead to damaging current levels; however, the current levels are sufficient to cause soft-failures and possibly lead to latch-up of the USB IC.

─ Theory and experiment of spherical aperture-coupled antennas with parasitic elements are presen... more ─ Theory and experiment of spherical aperture-coupled antennas with parasitic elements are presented in this paper. Current distributions on slot and conformal patches are calculated using spatial domain electric and magnetic Dyadic Green's Functions (DGFs). Electromagnetic fields for such a structure have been calculated with the aid of linear Rao-Wilton-Glisson (RWG) triangular basis functions and by converting spherical DGFs to Cartesian DGFs. In order to validate the proposed method, a prototype of this antenna is fabricated and tested. The effect of parasitic element on antenna characteristics such as gain and radiation pattern is investigated. Good agreement between the results shows accuracy and high convergence speed of the presented method. Index Terms Dyadic Green’s function, parasitic element, spherical aperture-coupled antennas, spherical to Cartesian transformation of DGFs.

2020 42nd Annual EOS/ESD Symposium (EOS/ESD), 2020

The ESD coupling path and on-board impedances strongly affect the ESD rise time seen on a PCB tra... more The ESD coupling path and on-board impedances strongly affect the ESD rise time seen on a PCB trace. Possible race conditions between external and on-die ESD protection were studied using measurement-based models of the transient response and on-board passives. Results show the interplay of rise time and protection turn-on can prevent the external TVS from responding in time.

Journal of The Textile Institute, Apr 10, 2023

IEEE Transactions on Electromagnetic Compatibility, Aug 1, 2020

The ability to predict the electric and magnetic fields generated by a component can solve many i... more The ability to predict the electric and magnetic fields generated by a component can solve many in-system interference problems before they occur. In this article, methods are presented to predict the high-frequency near electric and magnetic fields from a component using a method of moment approach. The current representation is estimated from a near electric-field scan by solving the electric field integral equation. The reconstruction method was validated with measurements of a test board containing a buffer integrated circuit. The current representation was shown to accurately predict fields at locations both above and to the side of the buffer with less than a 3.5-dB average error. Here, a near-field scan was only performed on a flat plane above the emitter and was used to predict sources to the side of the emitter. To accurately predict fields to the side of the emitter, the current representation must be defined on a surface between the emitter and the prediction location. An error analysis was performed to understand the impact of scan plane parameters, such as the size of the scan plane, the size of the current representation, and the relative distance between the current representation and the estimated fields on prediction accuracy.

IEEE Transactions on Electromagnetic Compatibility

IEEE Transactions on Antennas and Propagation

IEEE Transactions on Electromagnetic Compatibility

IEEE Access

An inverse method of moments (MoM) approach is developed to estimate the equivalent electric/magn... more An inverse method of moments (MoM) approach is developed to estimate the equivalent electric/magnetic current sources to predict radio frequency interference (RFI) in electronic devices. The proposed method is designed to reconstruct the noise sources in electronic devices containing multiple radiating elements by using a finite metal object carrying electric surface currents. The surface current elements are further applied to calculate the electromagnetic fields on arbitrary observation planes near the device under test (DUT). The method is validated through numerical simulation examples, including electrictype CPU noise, magnetic-type non-planar HDMI connector noise, printed circuit board (PCB) with Wi-Fi and PIFA antennas, and heat sink embedded in the DUT. The results confirm less than 0.4 dB difference in the predicted pattern at the antenna operating frequency when a triangular segmentation is applied in the vicinity of the noise source area, and the equivalent surface current is calculated at the edges of the Rao-Wilton-Glisson (RWG) meshes. The proposed method is a promising 'source reconstruction' candidate for predicting the near-field radiation characteristics of electronic devices with multiple peaks and nulls in the near-field radiation pattern. The method helps estimate the level of RFI by summing up the contributions of all the dipoles of the equivalent noise source derived by solving forward and inverse problems. The RFI results based on the inverse MoM approach are validated by comparing them with those obtained from CST simulation, and good agreement is achieved between the two.

Progress In Electromagnetics Research Letters, 2022

This letter proposes a novel analysis and design method of a continuously adjustable bandpass com... more This letter proposes a novel analysis and design method of a continuously adjustable bandpass combline filter. It investigates the feedline design specifications and introduces an external quality factor (Qext) tuning structure to achieve a constant fractional bandwidth over 60% tuning bandwidth. The design approach allows to determine the optimum feedline structure for the filter and is verified by full-wave simulation and measurement. The results show a constant fractional bandwidth of 4.5% over the entire operating frequency range between 225–400MHz.

IEEE Transactions on Electromagnetic Compatibility

In this paper, a new leaky wave antenna (LWA) based on complementary split- ring resonators (CSRR... more In this paper, a new leaky wave antenna (LWA) based on complementary split- ring resonators (CSRRs) and slot line are proposed. Efiects of CSRRs on beam scanning in a composite right/left handed (CRLH) LWA based on split-ring resonators (SRRs) are investigated. Actually, the efiects of these structures on the scan angles have been compared. The commercial Ansoft HFSS software is adopted for the simulations. The proposed LWA is analyzed in S and C band frequency, and the results reveal that the CSRR improves the gain in backward leaky wave radiation. The CSRR-LWA just scans the negative angles. Furthermore, the simulation results demonstrate the potential of the SRR-LWA to radiate from backward to forward scanning angles. As a result this miniaturized CSRR-LWA main beam can scan the space for C-band from i115 to i170 degree in phi = 0 (deg) plane. In the other word, the CSRR-LWA only scans in the negative ranges of theta, but SRR-LWA scans the space from +94 - to +156 - in positive r...

International Journal of Microwave and Wireless Technologies, 2018

In this paper, two new feed network designs for single layer and double layer slotted waveguide a... more In this paper, two new feed network designs for single layer and double layer slotted waveguide array antennas are presented. A microstrip to substrate integrated waveguide transition is applied to the single layer antenna. The aperture coupling mechanism is used in order to find the optimum feed network for double-layer structure and to obtain stable radiation characteristics over the frequency band. The prototypes of the proposed antennas have been fabricated and tested. The measured results were compared very well with the simulation results obtained from CST microwave studio and showed low side lobe level at the center frequency of 11.5 GHz for the low-profile 4-channel slotted waveguide arrays.

Journal of Information Systems and Telecommunication (JIST), Sep 1, 2013

Theory and experiment of a spherical probe-fed conformal antenna with a parasitic element mounted... more Theory and experiment of a spherical probe-fed conformal antenna with a parasitic element mounted on a spherical multilayer structure are presented in this paper. Rigorous mathematical Method of Moments (MoMs) for analyzing various radiating spherical structures is presented in this paper by using Dyadic Green's Functions (DGFs) in conjunction with Mixed Potential Integral Equation (MPIE) formulation. Linear Rao-Wilton-Glisson (RWG) triangular basis functions are applied in MPIE formulation. Current distributions on coaxial probe and conformal radiating elements are computed by using spatial domain Dyadic Green's Function (DGF) and its asymptotic approximation. A prototype of such an antenna is fabricated and tested. The effect of the parasitic element on the input impedance and radiation patterns of the antenna is investigated. It is shown that the antenna characteristics are improved significantly with the presence of the conducting parasitic element. Good agreement is achieved between the results obtained from the proposed methods and the measurement results.

2022 IEEE International Symposium on Electromagnetic Compatibility & Signal/Power Integrity (EMCSI)

2015 23rd Iranian Conference on Electrical Engineering, 2015

Presented is an ultra-broadband stripline directional coupler with significant improvement in its... more Presented is an ultra-broadband stripline directional coupler with significant improvement in its directivity parameter which is of interest in many measurement applications. The main focus of this paper is on the influence of using shunt stubs as capacitance compensators to improve specifications of wideband directional couplers. This improvement is performed on a two-layer non-uniform line directional coupler working in 2-18 GHz band. Experimental results, for various classes of wideband stripline couplers loaded with these stubs, exhibit remarkable improvement in the directivity parameter.

2 This paper presents two miniaturized slow wave structures in microstrip leaky-wave antennas (ML... more 2 This paper presents two miniaturized slow wave structures in microstrip leaky-wave antennas (MLWAs) which operate about 8 GHz. The effects of these structures on the scan angles have been compared in the paper. The designed interdigital capacitors and folded-back line have been investigated with ADS Momentum software. It has been shown that the interdigital capacitors (IDCs) yield to a broad scan angles from +53 to-74 degree, while the folded-back line inductor scans only the positive angles. Index Terms-leaky-wave antenna (LWA), scan angle, slow wave structure, periodic structure.

2021 IEEE International Joint EMC/SI/PI and EMC Europe Symposium, 2021

An IC protected by a transient voltage suppression (TVS) diode may fail if the TVS device does no... more An IC protected by a transient voltage suppression (TVS) diode may fail if the TVS device does not turn on or does not turn on quickly enough, causing the IC to take the full brunt of the ESD event. System Efficient ESD Design (SEED) simulation can help predict when the TVS will turn on and the level of ESD stress seen by the IC. In the following paper, models are developed to predict the voltage and current through a TVS and on-chip protection diodes connected to a USB cable when an ESD gun discharges to a pin at the end of the cable. A hybrid simulation methodology is proposed, which uses a full-wave model of the ESD gun, cable, and enclosure combined with the ESD protection devices and test board's circuit-level models. The response of the ESD protection is studied in simulation and measurement for a variety of cable configurations. Simulations of the voltage and current waveforms match measurements 24-35%. The total charge delivered to the on-chip diode as a function of ESD ...

Journal of Modeling in Engineering, 2016

A fourth-degree Substrate Integrated Waveguide (SIW) crossed coupled band pass filter for WLAN ba... more A fourth-degree Substrate Integrated Waveguide (SIW) crossed coupled band pass filter for WLAN band is designed by using a new negative coupling structure. It consists of two U shape microstrip lines on top and bottom planes with via holes at the center of them. This paper investigates the phase characteristics of negative and positive coupling structures and their effects. The design, fabrication and testing processes of the proposed filter are presented. The measured results seem to be consistent with the results obtained from simulator packages.

2018 IEEE International Reliability Physics Symposium (IRPS), 2018

This paper introduces the application of system-efficient ESD design (SEED) to ESD-induced pulses... more This paper introduces the application of system-efficient ESD design (SEED) to ESD-induced pulses that are typical for system-level ESD. Emphasis is given to USB connectors because it has been shown that discharges to the connector shell will not lead to damaging current levels; however, the current levels are sufficient to cause soft-failures and possibly lead to latch-up of the USB IC.

─ Theory and experiment of spherical aperture-coupled antennas with parasitic elements are presen... more ─ Theory and experiment of spherical aperture-coupled antennas with parasitic elements are presented in this paper. Current distributions on slot and conformal patches are calculated using spatial domain electric and magnetic Dyadic Green's Functions (DGFs). Electromagnetic fields for such a structure have been calculated with the aid of linear Rao-Wilton-Glisson (RWG) triangular basis functions and by converting spherical DGFs to Cartesian DGFs. In order to validate the proposed method, a prototype of this antenna is fabricated and tested. The effect of parasitic element on antenna characteristics such as gain and radiation pattern is investigated. Good agreement between the results shows accuracy and high convergence speed of the presented method. Index Terms Dyadic Green’s function, parasitic element, spherical aperture-coupled antennas, spherical to Cartesian transformation of DGFs.

2020 42nd Annual EOS/ESD Symposium (EOS/ESD), 2020

The ESD coupling path and on-board impedances strongly affect the ESD rise time seen on a PCB tra... more The ESD coupling path and on-board impedances strongly affect the ESD rise time seen on a PCB trace. Possible race conditions between external and on-die ESD protection were studied using measurement-based models of the transient response and on-board passives. Results show the interplay of rise time and protection turn-on can prevent the external TVS from responding in time.