There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Fundamentals, processes and applications of high-permittivity polymer–matrix composites

Damascene copper electroplating for on-chip interconnections, a process that we conceived and developed in the early 1990s, makes it possible to fill submicron trenches and vias with copper without creating a void or a seam and has thus proven superior to other technologies of copper deposition. We discuss here the relationship of additives in the plating bath to superfilling, the phenomenon that results in superconformal coverage, and we present a numerical model which accounts for the experimentally observed profile evolution of the plated metal.

Damascene copper electroplating for chip interconnections

Resonance conditions for a substrate-superstrate printed antenna geometry which allow for large antenna gain are presented. Asymptotic formulas for gain, beamwidth, and bandwidth are given, and the bandwidth limitation of the method is discussed. The method is extended to produce narrow patterns about the horizon, and directive patterns at two different angles.

Gain enhancement methods for printed circuit antennas

In this paper, we propose a blockchain inspired Internet-of-Things architecture for creating a transparent food supply chain. The architecture uses a proof-of-object-based authentication protocol, which is analogous to the cryptocurrency’s proof-of-work protocol. The complete architecture was realized by integrating a radio frequency identification (RFID)-based sensor at the physical layer and blockchain at the cyber layer. The RFID provides a unique identity of the product and the sensor data, which helps in real time quality monitoring. For this purpose, a small feature size 900-MHz RFID coupled sensor was fabricated and demonstrated for real time sensor data acquisition. The blockchain architecture aids in creating a tamper-proof digital database of the food packages at each instance. A detailed security analysis was performed to investigate the vulnerability of the proposed architecture under different types of cyber attacks.

Blockchain Inspired RFID-Based Information Architecture for Food Supply Chain

This paper discuses the design, materials, fabrication and measurements of a novel integrated decoupling capacitor for MCM-L-based substrates. Based on modeling using the SLA Roadmap, it has been estimated that 13-72 nF/cm/sup 2/ of specific decoupling capacitance will be required for the next decade. The capacitor in this paper addresses this need. The fabrication of the capacitor has been achieved using filled polymer materials in thin film form, with via diameters of 100 um and below, through photodefinable processes. Dielectric constant as high as 65 with loss tangent below 0.05 and specific capacitance of 22 nF/cm/sup 2/ have been achieved. The scattering parameters were measured up to 20 GHz using a network analyzer for various capacitor structures to study input impedance and scaling of the devices. Input impedance of the capacitor is found to be low in the GHz range. The polymer-filled materials and capacitor structures are also scalable to a variety of sizes and values.

A novel integrated decoupling capacitor for MCM-L technology

A method for predicting the behavior of the permittivity and permeability of an engineered material by examining the measured S-parameters of a material sample is devised, assuming that the sample is lossless and symmetric. The S-parameter conditions under which the material parameters extracted using the Nicolson-Ross-Weir method may be associated with a lossless homogeneous material are described. Also, the relationship between the signs of the real and imaginary parts of the permittivity and permeability are determined, both when the extracted material parameters are real and when they are complex. In particular, the conditions under which metamaterials exhibit double-negative properties may be predicted from the S-parameters of a metamaterial sample. The relationships between material characteristics and the S-parameters should prove useful when synthesizing materials to have certain desired properties. Examples, both from experiment and simulation, demonstrate that the relationships may be used to understand the behavior of several different categories of engineered materials, even when the materials have appreciable loss.

https://www.jpier.org/PIER/pier157/03.16071706.pdf

Analysis of the Nicolson-Ross-Weir Method for Characterizing the Electromagnetic Properties of Engineered Materials

In this paper, terahertz (THz) characterization of dielectric substrates, THz planar and quasi-optical components, THz probing of planar devices, and THz nondestructive evaluation (NDE) are demonstrated. In particular, the goals of this paper are: 1) characterization of dielectric substrates for THz packaging applications; 2) design, fabrication, and evaluation of THz components built using some of these dielectric substrates; and 3) the use of the dielectric characterization approach and dielectric properties in NDE of electronic packages. The background theory for characterizing dielectric substrates using THz time-domain signals is provided. The Nelder and Mead modified simplex optimization algorithm is utilized in order to extract the dielectric properties of different packaging materials encompassing organic, inorganic, and composite materials. A planar THz power splitter, a dielectric probe, and a low-cost polymer-based quasi-optical band-stop interference filter are demonstrated. THz NDE of electronics packages is demonstrated for packaging delamination and moisture ingression in dielectric films.

Terahertz Characterization of Dielectric Substrates for Component Design and Nondestructive Evaluation of Packages

Printing techniques for the fabrication of diodes have received increasing attention over the last decade due to their great potential as alternatives for high-throughput and cost-effective manufacturing approaches compatible with both flexible and rigid substrates. Here, the progress achieved and the challenges faced in the fabrication of printed diodes are discussed and highlighted, with a focus on the materials of significance (silicon, metal oxides, nanomaterials, and organics), the techniques utilized for ink deposition (gravure printing, screen printing, inkjet printing, aerosol jet printing, etc.), and the process through which the printed layers of diode are sintered after printing. Special attention is also given to the device applications within which the printed diodes have been successfully incorporated, particularly in the fields of rectification, light emission, energy harvesting, and displays. Considering the unmatched production scalability of printed diodes and their intrinsic suitability for flexible and wearable applications, significant improvement in performance and intensive research in development and applications of the printed diodes will continuously progress in the future.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/advs.201801653

Premjeet Chahal

Papers

Blockchain Inspired RFID-Based Information Architecture for Food Supply Chain

A novel integrated decoupling capacitor for MCM-L technology

Analysis of the Nicolson-Ross-Weir Method for Characterizing the Electromagnetic Properties of Engineered Materials

Terahertz Characterization of Dielectric Substrates for Component Design and Nondestructive Evaluation of Packages

Printed Diodes: Materials Processing, Fabrication, and Applications.