Integral Equation Methods for Electromagnetic and Elastic Waves is an outgrowth of several years of work. There have been no recent books on integral equation methods. There are books written on integral equations, but either they have been around for a while, or they were written by mathematicians. Much of the knowledge in integral equation methods still resides in journal papers. With this book, important relevant knowledge for integral equations are consolidated in one place and researchers need only read the pertinent chapters in this book to gain important knowledge needed for integral equation research. Also, learning the fundamentals of linear elastic wave theory does not require a quantum leap for electromagnetic practitioners.

The super‐hyper singularity treatment is developed for solving three‐dimensional (3D) electric field integral equations (EFIE). EFIE usually takes two forms: one of which includes a super‐hyper singular kernel generated by the double gradient of the Green's function. So far, there is no way to evaluate these super‐hyper singular integrals needed for constructing the pertinent matrix equation. We apply the series expansion of the Green's function to the super‐hyper singular kernel and derive closed‐form expressions for their evaluations in the Cauchy principal‐value sense. The derivation is based on the constant current approximation over a flat triangle patch, but it can be extended easily to higher‐order approximations of the current. The scheme can be used to accurately calculate the near and self interaction terms in the impedance matrix for the method of moments (MoM), Nyström method or boundary element method (BEM). © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1383–1388, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22443

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Sensors are key components in structural health monitoring. Although significant improvements have been made on monitoring technologies by using many advanced smart sensors, the need of cables and power supplies still causes much inconvenience in the practical implementation of these technologies. In this paper, we propose a novel rectangular patch antenna to monitor the structural health in a wireless and passive manner so that the drawback of traditional monitoring methods can be fully overcome. The antenna is used as a sensor and its resonant frequency will change linearly in terms of its size changes in both horizontal and vertical directions. The antenna will transmit an electromagnetic wave with the resonant frequency information to a reader by a long distance and activate the chip in the reader. According to the received information about the resonant frequency, the change of the targeted structure's strain can be measured in real time and its health state can then be evaluated. Simulations and experiments show that the designed antenna is an excellent strain sensor and can be applied to the health detection for many types of structure.

We discuss a non-invasive technique to detect glucose changes with enhanced sensitivity based on parity-time (PT) symmetry. We detect glucose level changes within the skin by measuring the frequency shift in the electromagnetic resonance induced within a PT-symmetric system that sandwiches the tissue sample under analysis. Even though the sample itself is lossy, and therefore resonances would be damped, the introduction of balanced gain and loss enables an efficient sensing mechanism that bypasses the conventional limitations of passive sensing schemes. Our results indicate that the resonance shift can be made fairly linear with respect to the glucose concentration variations, and the expected accuracy is large. We also investigate a realistic system to implement the non-invasive PT-symmetric glucose