top of page

Support Group

Public·12 members

Microwave Electronics Measurement And Materials...

This book will appeal to practising engineers and technicians working in the areas of RF, microwaves, communications, solid-state devices and radar. Senior students, researchers in microwave engineering and microelectronics and material scientists will also find this book a very useful reference.

Microwave Electronics Measurement and Materials...

Download File:

Microwave materials have been widely used in a variety ofapplications ranging from communicationdevices to militarysatellite services, and the study of materials properties atmicrowave frequenciesand the development of functional microwavematerials have always been among the most active areasinsolid-state physics, materials science, and electrical andelectronic engineering. In recent years, theincreasing requirementsfor the development of high-speed, high-frequency circuits andsystems requirecomplete understanding of the properties ofmaterials functioning at microwave frequencies. All theseaspectsmake the characterization of materials properties an important eldin microwave electronics.

Characterization of materials properties at microwavefrequencies has a long history, dating from theearly 1950s. In pastdecades, dramatic advances have been made in this eld, and a greatdeal of newmeasurement methods and techniques have been developedand applied. There is a clear need to have apractical referencetext to assist practicing professionals in research and industry.However, we realizethe lack of good reference books dealing withthis eld. Though some chapters, reviews, and bookshave beenpublished in the past, these materials usually deal with only oneor several topics in thiseld, and a book containing a comprehensivecoverage of up-to-date measurement methodologies is notavailable.Therefore, most of the research and development activities in thiseld are based primarilyon the information scattered throughoutnumerous reports and journals, and it always takes a great dealoftime and effort to collect the information related to on-goingprojects from the voluminous literature.Furthermore, because of thepaucity of comprehensive textbooks, the training in this eld isusually notsystematic, and this is undesirable for further progressand development in this eld.

This book deals with the microwave methods applied to materialsproperty characterization, and itprovides an in-depth coverage ofboth established and emerging techniques in materialscharacterization.It also represents the most comprehensivetreatment of microwave methods for materialspropertycharacterization that has appeared in book form to date.Although this book is expected to be mostuseful to those engineersactively engaged in designing materials propertycharacterizationmethods, itshould also be of considerable value to engineers inother disciplines, such as industrial engineers,bioengineers, andmaterials scientists, who wish to understand the capabilities andlimitations ofmicrowave measurement methods that they use.Meanwhile, this book also satises the requirement forup-to-datetexts at graduate and senior undergraduate levels on the subjectsin materials characterization.

The two introductory chapters, Chapter 1 and Chapter 2, areintended to acquaint the readers with thebasis for the research andengineering of electromagnetic materials from the materials andmicrowavefundamentals respectively. As general knowledge ofelectromagnetic properties of materials is helpfulfor understandingmeasurement results and correcting possible errors, Chapter 1introduces the general

The electrical transport properties at microwave frequencies areimportant for the development of high-speed electronic circuits.Chapter 11 discusses the microwave Hall effect techniques for themeasurementof the electrical transport properties oflow-conductivity, high-conductivity, and magnetic materials.

Firstly, though it is an old eld in physics,the study ofelectromagnetic properties of mate-rials at microwave frequenciesis full of academicimportance (Solymar and Walsh 1998; Kittel1997;Von Hippel 1995a,b; Jiles 1994; Robert 1988),especially formagnetic materials (Jiles 1998; Smit1971) and superconductors(Tinkham 1996) andferroelectrics (Lines and Glass 1977). Theknowl-edge gained from microwave measurements con-tributes to ourinformation about both the macro-scopic and the microscopicproperties of materi-als, so microwave techniques have beenimportantfor materials property research. Though magneticmaterialsare widely used in various elds, theresearch of magnetic materialslags far behind theirapplications, and this, to some extent,hinders usfrom making full application of magnetic mate-rials.Until now, the electromagnetic propertiesof magnetic properties atmicrowave frequencieshave not been fully investigated yet, and thisisone of the main obstacles for the development ofmicrowavemagnetoelectrics. Besides, one of themost promising applications ofsuperconductors ismicrowave electronics. A lot of effort hasbeenput in the study of the microwave propertiesof superconductors,while many areas are yet tobe explored. Meanwhile, as ferroelectricmateri-als have great application potential in developingsmartelectromagnetic materials, structures, and

and magnetic material to indicate the dominantresponses ofdifferent types of materials. Allmaterials have some response tomagnetic eldsbut, except for ferromagnetic and ferrimagnetictypes,their responses are usually very small,and their permeabilityvalues differ from 0 bya negligible fraction. Most of theferromagneticmaterials are highly conductive, but we callthemmagnetic materials, as their magnetic propertiesare the mostsignicant in their applications. Forsuperconductors, the Meissnereffect shows thatthey are a kind of very special magneticmaterials,but in microwave electronics, people are moreinterestedin their surface impedance.

Dielectric heating was investigated in 2018 by Liu et al. [14] and Zhang et al. [15]. Both compared it to conventionally heated fibers. Liu et al. suggested the skin-core structure is less distinctive due to the volumetric heating effect of the microwaves [14]. Microwave heating shortened the process time by 35 min and reduced the process temperature by 30 C. However, the fiber was tied to a ceramic rod, and no dielectric properties were provided. Moreover, neither the location nor the method for the fiber temperature measurement is mentioned. In [15] it is stated that microwave heating shortens reaction time and improves the fiber surface. Again, the fibers are attached to a ceramic rod, and no dielectric properties are provided. It can be assumed that the microwave was predominantly heating the ceramic rod at the beginning, and the fiber is heated via thermal conduction. Only later in the process, when dielectric loss of the fibers is increasing with temperature, to some extent a direct microwave heating effect might take place. But as no dielectric properties are provided, it is not possible to definitely draw this conclusion. In [16], Zhao et al. investigate the influence of microwave oxidation on the reaction mechanisms and the fiber structure. They describe an improvement of the structure caused by reduced surface defects.

Traceable measurements of microwave power are the basis of current and future wireless hardware. Particularly relevant to the wireless industry are modulated signal measurements and accurate evaluation of systems, components and devices. The industry also requires a trusted determination of impedance of a reference environment, which can in turn be used in linear transformations to target reference planes. NIST CTL provides these fundamentals and works to disseminate measurement data, analysis techniques and modeling to the communications community.

Dielectric constant or relative permittivity is one of the most important characteristics of materials whose accurate determination is crucial in various areas such as the food industry, agriculture, medicine, health-care, and military and defense1,2. Accurate determination of materials needs sensing methods for characterization of dielectric materials. Methods based on RF and microwave measurements are amongst the most reliable candidates to provide accurate results3,4,5. These methods have evolved over time and mostly originated from other technologies that were intended for a completely different purpose, mainly for signal or energy transmission, such as the coaxial probe, the microstrip transmission line, the free-space propagation method, and the parallel plate waveguide. All these techniques were based on measuring the reflection coefficient with and without the material under test. The major challenge with all these methods is the device physical profile and sensitivity. The cavity resonator method provides very high accuracy and are less sensitive to noise and undesired loss and phase shift generated during measurement6,7. However, this method is not flexible for measuring a wide range of materials or different concentrations of different materials since different resonators need to be used.

We have a position for postdoc scholar. Candidates must hold (or expect) a PhD degree in experimental condensed matter physics or related fields. Expertise in one or more of the following areas is preferred: 1) cryogenic instrumentation and transport measurement; 2) low dimensional materials; 3) scanning probe microscopy; 4) microwave electronics. Interested candidates please send a CV along with a brief description of research interest to Dr. Cui.

A review of measurement methods of the basic electromagnetic parameters of materials at microwave frequencies is presented. Materials under study include dielectrics, semiconductors, conductors, superconductors, and ferrites. Measurement methods of the complex permittivity, the complex permeability tensor, and the complex conductivity and related parameters, such as resistivity, the sheet resistance, and the ferromagnetic linewidth are considered. For dielectrics and ferrites, the knowledge of their complex permittivity and the complex permeability at microwave frequencies is of practical interest. Microwave measurements allow contactless measurements of their resistivity, conductivity, and sheet resistance. These days contactless conductivity measurements have become more and more important, due to the progress in materials technology and the development of new materials intended for the electronic industry such as graphene, GaN, and SiC. Some of these materials, such as GaN and SiC are not measurable with the four-point probe technique, even if they are conducting. Measurement fixtures that are described in this paper include sections of transmission lines, resonance cavities, and dielectric resonators. 041b061a72


Welcome to the group! You can connect with other members, ge...
Group Page: Groups_SingleGroup
bottom of page