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Frequency Selective Surfaces: Theory and Design

"...Ben has been the world-wide guru of this technology, providing support to applications of all types. His genius lies in handling the extremely complex mathematics, while at the same time seeing the practical matters involved in applying the results. As this book clearly shows, Ben is able to relate to novices interested in using frequency selective surfaces and to explain technical details in an understandable way, liberally spiced with his special brand of humor... Ben Munk has written a book that represents the epitome of practical understanding of Frequency Selective Surfaces. He deserves all honors that might befall him for this achievement." -William F. Bahret.

Mr. W. Bahret was with the United States Air Force but is now retired. From the early 50s he sponsored numerous projects concerning Radar Cross Section of airborne platforms in particular antennas and absorbers. Under his leadership grew many of the concepts used extensively today, as for example the metallic radome. In fact, he is by many considered to be the father of stealth technology.

"This book compiles under one cover most of Munk's research over the past three decades. It is woven with the physical insight that he has gained and further developed as his career has grown. Ben uses mathematics to whatever extent is needed, and only as needed. This material is written so that it should be useful to engineers with a background in electromagnetics. I strongly recommend this book to any engineer with any interest in phased arrays and/or frequency selective surfaces. The physical insight that may be gained from this book will enhance their ability to treat additional array problems of their own." -Leon Peters, Jr.

Professor Leon Peters, Jr., was a professor at the Ohio State University but is now retired. From the early sixties he worked on, among many other things, RCS problems involving antennas and absorbers.

This book presents the complete derivation of the Periodic Method of Moments, which enables the reader to calculate quickly and efficiently the transmission and reflection properties of multi-layered Frequency Selective Surfaces comprised of either wire and/or slot elements of arbitrary shape and located in a stratified medium. However, it also gives the reader the tools to analyze multi-layered FSS's leading to specific designs of the very important Hybrid Radome, which is characterized by constant band width with angle of incidence and polarization. Further, it investigates in great detail bandstop filters with large as well as narrow bandwidth (dichroic surfaces). It also discusses for the first time, lossy elements used in producing Circuit Analog absorbers. Finally, the last chapter deals with power breakdown of FSS's when exposed to pulsed signals with high peak power.

The approach followed by most other presentations simply consists of expanding the fields around the FSS, matching the boundary conditions and writing a computer program. While this enables the user to obtain calculated results, it gives very little physical insight and no help in how to design actual multi-layered FSS's. In contrast, the approach used in this title analyzes all curves of desired shapes. In particular, it discusses in great detail how to produce radomes made of FSS's located in a stratified medium (Hybrid Radomes), with constant band width for all angles of incidence and polarizations. Numerous examples are given of great practical interest. More specifically, Chapter 7 deals with the theory and design of bandpass radomes with constant bandwidth and flat tops. Examples are given for mono-, bi- and tri-planar designs. Chapter 8 deals with bandstop filters with broad as well as narrow bandwidth. Chapter 9 deals with multi-layered FSS of lossy elements, namely the so-called Circuit Analog Absorbers, designed to yield outstanding absorption with more than a decade of bandwidth.

Features material previously labeled as classified by the United States Air Force.

Lowenstark's Log: 04-21-XX

What a day.

Got a chance to scan Sagira - who refers to me as father now, and, admittedly, the gesture moved me deeply (yeah, it's a litte cheesy, but keep that opinion to yourself, journal) - to find out the nature of her cyber-decay. The good news is that the surgery on the device can be done remotely. It's a cutting edge cyberdevice that can be modified electromagnetically - reacting to certain microwave frequencies and magnetic waves. This means: No surgery. Just a lot of power usage.

So we're gonna get that done soon - once I finish configuring my microwave and electromagnetic emitters inside of the cryopods. Mental note: Thank Arson for the new parts for those things.

I can't help but feel some predestined connection with little Sagira. She calls me Aba - Father, I call her Saghira (or Sagira) - little girl.

I don't deny that this is odd. I hardly know her. But I freed her a year ago, and broke WU law doing it.. And it was one of the major turning points of my life. Of the change I underwent toward the greater good. Maybe it's nostalgic, maybe it's metaphorical... whatever it is, I feel a connection with this kid. And I'll do my damndest to keep her safe and healthy.

Other news: V - for some reason as of yet unrevealed to me - kicked Bianca from the Ghost Training program. B was PIIISSSSEED. Can't blame her. She sneaks into my dreams every night, so she must be stealthy right?

Lastly: Got the genetic profile back on Arre. Get this: Not only is he an Alpha Labs project like Volpe, but he's also her BROTHER. No shit. Couldn't make that shit up.

They both looked ecstatic over the news, which I don't doubt, as V needs family. Bad. She's such a loner...

maybe this will be great for her. I really, really hope it will be. She could use a brother.

Through relatively simple maths, you can work out a set of electromagnetic material properties - anisotropic, frequency dependent and smoothly varying in space - that when applied to a cylindrical or spherical cloak will bend all incident light around what is inside. As a result, Harry and his cat become completely invisible.

The remaining challenge, which has already been taken up by a number of research groups around the world, is to manufacture the materials. In practice, they are still looking at layered metamaterial approximations working reasonably well only for particular microwave wavelengths.

This accessible and comprehensive book provides an introduction to the basic concepts and key circuits of radio frequency systems, covering fundamental principles that apply to all radio devices, from wireless data transceivers on semiconductor chips to high-power broadcast transmitters. Topics covered include filters, amplifiers, oscillators, modulators, low-noise amplifiers, phase-locked loops, and transformers. The author describes applications of radio frequency systems in such areas as communications, radio and television broadcasting, radar, and radio astronomy. The book contains many exercises, and assumes only a knowledge of elementary electronics and circuit analysis. It will be an ideal textbook for junior and senior courses in electrical engineering, as well as an invaluable reference for researchers and professional engineers in this area, or for those moving into the field of wireless communications.