In this letter, a miniature wide-band 1 × 2 antenna is proposed. The proposed antenna has a wider impedance bandwidth, 70% and small size, 31 × 20 × 1.6 mm3. There is a good isolation between two antennas, below −15 dB in the operating band. A monopole configuration is used to achieve the wide-band response and a mushroom type Electronics Band-gap structure is incorporated between the two antennas to achieve better isolation. Proposed antenna is simulated using High-Frequency Structure Simulator and a prototype is tested on Vector Network Analyzer. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1294–1298, 2016

Compact MIMO antenna

A novel technique for mitigating simultaneous switching noise propagation in high-speed printed circuit boards is presented The proposed concept is based on etching complementary split-ring resonators (CSRRs) on only one metallic layer of the printed circuit board By such topology, the electric field between the power planes can be suppressed It is shown here that by concentrically cascading CSRRs, an ultrawideband suppression of switching noise from sub-GHz to 12 GHz is achieved A prototype of the proposed concept was simulated, fabricated, and tested Good agreement is observed between simulation and measurement Moreover, electromagnetic interference radiation from such perforated boards is investigated Finally, the performance of the proposed board with CSRRs is assessed through signal integrity analysis using eye diagrams and compared with a reference (solid) board

Ultrawideband Mitigation of Simultaneous Switching Noise and EMI Reduction in High-Speed PCBs Using Complementary Split-Ring Resonators

A Low Mutual Coupling Design for Array Microstrip Antennas Integrated with Electromagnetic Band-Gap Structures

The paper presents the results of development of TEM cell with a working volume of $30\times 30\times 5 mm^{3}$ for measuring radiated immunity and electromagnetic emissions of low-profile integrated circuits. A solid model of the TEM cell was developed based on the analysis of various designs for matching transitions using analytical estimation and electrodynamic simulation. A research prototype of the cell was built and its S-parameters measurements were performed.

TEM cell for Testing Low-profile Integrated Circuits for EMC

Comprehensive study on the source of electromagnetic radiation from apertures placed in conducting screens and enclosure is presented Novel technique comprising placement of electromagnetic bandgap (EBG) structures immediately around the apertures openings is presented to suppress the surface currents and consequently to reduce the radiation from the apertures The effectiveness of the proposed technique is demonstrated through several detailed parametric studies and numerical full-wave simulations quantifying the strength of electromagnetic fields in near and far regions from the aperture In fact, using the EBG structures, more than 20-dB reduction is achieved in the near- and far-field radiation without affecting the aperture size Finally, a detailed experimental case study from real-world environment is presented to validate the proposed concept

Reduction of Electromagnetic Radiation from Apertures and Enclosures Using Electromagnetic Bandgap Structures

Electromagnetic bandgap (EBG) structures are considered as a viable solution for the problem of switching noise in printed circuit boards and packages. Less attention, however, has been given to whether or not the introduction of EBGs affect the EMI potential of the circuit to couple unwanted energy to neighboring layers or interconnects. In this paper, we show that the bandgap of EBG structures, as generated using the Brillouin diagram, does not necessarily correspond to the suppression bandwidth generated using S-parameters. In fact, we show that the slow modes which typically exist at the edges of the bandgap of periodic structures contribute to increased radiation, even within the suppression band obtained from the S-parameters. We validate this finding using numerical simulation. Based on this work, design guidelines for EBG structures can be drawn to insure not only suppression of switching noise but also minimization of EMI.

Radiating emissions from the planar electromagnetic bandgap (EBG) structures

Electromagnetic bandgap structures are considered a viable solution for the problem of switching noise in printed circuit boards and packages. Less attention, however, has been given to whether or not the introduction of EBGs affects the EMI potential of the circuit to couple unwanted energy to neighboring layers or interconnects. In this paper, we show that the bandgap of EBG structures, as generated using the Brillouin diagram, does not necessarily correspond to the suppression bandwidth typically generated using S-parameters. We show that the reactive near fields radiating from openings within the EBG layers can be substantial and are present in the entire frequency band including propagating and nonpropagating mode regions. These fields decay fast with distance; however, they can couple significant energy to adjacent layers and to signal lines. The findings are validated using full-wave three-dimensional numerical simulation. Based on this work, design guidelines for EBG structures can be drawn to insure not only suppression of switching noise but also minimization of EMI and insuring signal integrity.

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On the Suppression Band and Bandgap of Planar Electromagnetic Bandgap Structures

Electromagnetic bandgap structures are frontrunners in solving GHz switching noise in printed circuit boards and packages. However, less attention has been given to whether or not the introduction of EBGs affect the EMI potential of the circuit to couple unwanted energy to neighboring layers or interconnects. In this paper, we show that the bandgap of EBG structures, as generated using the Brillouin diagram, does not necessarily correspond to the suppression bandwidth typically generated using S-parameters. We show that the reactive near fields radiating from openings within the EBG layer can be substantial and are present in the frequency band including propagating and non-propagating mode regions. These fields decay fast with distance, however, they can couple significant energy to adjacent layers and to signal lines. Based on this work, design guidelines for EBG structures can be drawn to insure not only suppression of switching noise but also minimization of EMI and insuring signal integrity.

Reactive power radiated from the planar electromagnetic bandgap structures, a source of EMI in high speed packages

In this article the design, fabrication, and testing of several electromagnetic band gap (EBG) structures used to mitigate switching noise in high speed printed circuit boards is presented. Some features of these surfaces are considered as variables and results from different band gap prediction techniques are compared to actual fabricated parallel plate waveguides. The strength and weaknesses of these prediction techniques is shown and the power of full wave analysis to predict the band gap of these EBG structures and the limitation of simple L-C models are discussed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1792–1795, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25327

Baharak Mohajer-Iravani

Papers

Radiating emissions from the planar electromagnetic bandgap (EBG) structures

On the Suppression Band and Bandgap of Planar Electromagnetic Bandgap Structures

Reactive power radiated from the planar electromagnetic bandgap structures, a source of EMI in high speed packages

Prediction of the gap of electromagnetic band gap structures in a parallel-plate waveguide environment