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Novel microwave and millimeterwave (mm-wave) bandstop filters using artificial periodic substrate electromagnetic bandgap (EBG) are investigated in this paper. Three types of microstrip structures using periodically modified trace width, patterned dielectric substrate, and periodically modified ground plane are treated, respectively. By periodically modifying either the width of the conductor trace, the substrate height, or the dielectric constant of a standard microstrip transmission line, it has been possible to design microwave bandstop filter functions with wide stopband characteristics and reduced size, compared to conventional microwave lRF filter structures. Commercial electronic design automation (EDA) and computational electromagnetic tools such as Agilent's advanced design system (ADS) and CST Microwave Studio are used in the design and simulations of these filter structures. The effects of the physical parameters of the structures on the filter characteristic are studied. The design procedure and simulation results are described and possible applications of these filter structures are discussed in this paper. A particularly wide stopband is achieved by the circuits presented in this paper, which use only a few cell elements. A significant performance improvement of microstrip patch antenna has been observed by implementing one of the presented EBG periodic substrate structures. [ABSTRACT FROM AUTHOR]

High-frequency transmission lines crosstalk reduction using spacing rules is treated in this paper. Two of the most popular planar transmission line configurations, namely microstrip and stripline, commonly used in printed circuit boards and radio frequency/microwave integrated circuits, are considered in this work. The trace separation between two adjacent transmission lines of each type is stepwise increased as function of the trace width. The single-ended transmission line structures are numerically investigated by a frequency-based 3-D full-wave electromagnetic analysis tool. A particular case using coated microstrip transmission lines has been fabricated, along with some calibration structures, to allow direct measurement and experimental analysis of crosstalk between the single-ended transmission lines. The test structures are characterized at high-frequency (up to 20 GHz) with scattering parameters using a vector network analyzer. The experimental results are compared with the simulation data, and some conclusions and suggestions on the impact and use of spacing rules for high-frequency crosstalk reduction between single-ended transmission lines are presented. These investigations emphasize the necessity of reevaluating classical design rules for their suitability in high-frequency applications. [ABSTRACT FROM AUTHOR]

In this paper, the problem of using guard traces for reducing crosstalk between differential transmission line pairs is investigated, both experimentally and by full-wave electromagnetic (EM) simulations. Different cases of differential lines crosstalk are treated with and without guard trace separation between the differential line pairs. Coated microstrip printed circuit board test structures including thru-reflect-line calibration standards are designed and fabricated on a high frequency laminate material, allowing direct measurement of crosstalk between adjacent differential line pairs in the absence and in the presence of guard traces stitched with vias of regular spacing. The test structures are characterized with mixed-mode scattering parameters using a physical layer test system. Different configurations (of differential line pairs) without guard trace, with floating guard traces (which are terminated and nonterminated) and with a solid guard trace separation are investigated using a High Frequency Structure Simulator (a commercial full-wave 3-D EM simulation tool). The experimental data are compared with the simulation results, and some conclusions and guidelines on the effect of guard traces for alleviating crosstalk between differential transmission lines are presented. [ABSTRACT FROM AUTHOR]

To be able to reduce the size of products having electronic devices, it becomes more and more important to miniaturize the electromechanical parts of the system. The use of micromechanical connectors and contact structures implies the need of methods for estimating the properties of such devices. This work will, by use of finite element modeling, treat the influence of a thin film constituting at least one of the contacting members of an electrical contact. The error introduced by using the traditional Maxwell/Holm contact constriction resistance theory will be investigated. Numerical methods are used to present a way to approximate the total resistance for the thin metal film contact. [ABSTRACT FROM AUTHOR]

The integration of more and more functionality into smaller and smaller form factor electronic products, drives the need for denser chip to substrate interconnect systems. As the number of I/O pins increases, the use of area array chips or packages becomes inevitable. Metal patterned elastomer chip sockets have now been improved to work with contact densities as high as 80 000 contacts/cm² corresponding to a pitch of 36 μm. Sockets with 10 000 contacts and a 72-μm pitch have survived more than 400 cycles in air-to-air thermal cycling chambers as well as freezing shocks caused by dipping into liquid nitrogen. Although the daisy chain test circuits breaks for temperatures lower than -50 °C and higher than 90 °C, they always return to the initial resistance values when entering the normal temperature range. The combination of a gold-to-gold contact interface and the elastic features of the contact bumps makes this socket an ideal compliance layer between bare chips and different types of carrier substrates, reducing the problems caused by thermomechanical mismatch between the substrate and the chip. Bad dies can easily be replaced, since the chip is not soldered or glued to the socket. The size and the possibility to control the geometry of the contacts provides means to maintain a good high-frequency characteristic impedance matching all the way to the chip pad. [ABSTRACT FROM AUTHOR]

Provides information on a study that developed an elastic chip socket to avoid the problem with thermo-mechanical stress induced fatigue using conventional flip-chip mounting of bare chips. Methodology of the study; Results and discussion on the study.

Printed electronics are considered for wireless electronic tags and sensors within the future Internet-of-things (loT) concept. As a consequence of the low charge carrier mobility of present printable organic and inorganic semiconductors, the operational frequency of printed rectifiers is not high enough to enable direct communication and powering between mobile phones and printed e-tags. Here, we report an all-printed diode operating up to 1.6 GHz. The device, based on two stacked layers of Si and NbSi2 particles, is manufactured on a flexible substrate at low temperature and in ambient atmosphere. The high charge carrier mobility of the Si microparticles allows device operation to occur in the charge injection-limited regime. The asymmetry of the oxide layers in the resulting device stack leads to rectification of tunneling current. Printed diodes were combined with antennas and electrochromic displays to form an all-printed e-tag. The harvested signal from a Global System for Mobile Communications mobile phone was used to update the display. Our findings demonstrate a new communication pathway for printed electronics within loT applications. [ABSTRACT FROM AUTHOR]