Literature Review on Metamaterial

Literature Review on Metamaterial LITERATURE REVIEW ON METAMATERIAL The Left-Handed Metamaterial (LHM) has a few unique properties such as negative refraction and backward wave. In this chapter, the basic theories behind their unique properties are presented and some applications of LHM toward the antenna application are discussed. DEFINITION BACKGROUND OF LEFT-HANDED METAMATERIAL Electromagnetic Metamaterial can be defined as artificial effective homogenous electromagnetic structures with unusual properties not readily found in nature . A Left-Handed Metamaterial (LHM) [17][18]or Double Negative Metamaterial (DNG) is an electromagnetic Metamaterial that exhibit negative permittivity and permeability. This phenomenon can be characterized by the negative refraction index and the anti-parallel phase velocity which is also known as backward wave. HISTORY OF LEFT-HANDED METAMATERIAL (LHM) The initial work on LHM was started by V. G. Veselago from the Lebedjev Physical Institute in Moscow when he made a theoretical speculation of this artificial material that exhibit negative permittivity and negative permeability. Veselago speculation remain silent for 29 years until 1996, J. B. Pendry from Imperial College London and his co-author form GEC-Marconi published a paper about artificial metallic construction which exhibit negative permittivity and negative permeability. Following this interesting discovery, in 2001, the first experimental verification was made by Shelby, Smith and Schultz at the University of California. The left handed material structure consists of split ring resonator and thin wire inspired by J. B. Pendry as shown in figure 3.1. Figure 3.1: First experimental LHM structure Since the introduction of LHM twelve years ago, many researchers were interested in investigating this artificial material and several of them was using LHM to improve the properties of the microwave devices such as antennas and filters. Many papers have been published regarding the LHM integrated with antennas and their properties have been analyzed. The focusing affect of LHM has made a low gain antenna becomes directive and have an increment of gain. FEATURES OF METAMATERIAL Improvement in the performance of a small monopole antenna, realized via the use of an ENG envelope that compensates for its high capacitive reactance. Lens effect produced by DNG slabs that are useful for enhancing the directivities of a small antennas, e.g. dipole and Microstrip patches, by collimating the cylindrical waves emanating from these antennas and focusing them at infinity. Creation of super lenses which can have a spatial resolution below that of the wavelength. UNIQUE PROPERTIES OF LEFT-HANDED METAMATERIALS Negative Refractive Index: For conventional material with à °Ã‚ Ã…“â‚ ¬r > 0 and à °Ã‚ Ã…“†¡r > 0, the refractive index is givenà °Ã‚ Ã¢â‚¬ËœÃ¢â‚¬ º=√à °Ã‚ Ã…“†¡Ãƒ °Ã‚ Ã¢â‚¬ËœÃ… ¸Ãƒ °Ã‚ Ã…“â‚ ¬Ãƒ °Ã‚ Ã¢â‚¬ËœÃ… ¸, so that the conventional material possesses a positive refractive index. Yet, Left-handed Meta-material has both negative permittivity (à °Ã‚ Ã…“â‚ ¬r à °Ã‚ Ã…“† r à °Ã‚ Ã…“† The Snells law is described as ..3.3.1(a) Where à °Ã‚ Ã…“Æ’2 the incident is angle and à °Ã‚ Ã…“Æ’1 is the refraction angle. Supposing medium I and medium II are conventional materials with à °Ã‚ Ã¢â‚¬ËœÃ¢â‚¬ º1>0 and à °Ã‚ Ã¢â‚¬ËœÃ¢â‚¬ º2>0 respectively, them refracted light will be bent with positive ÃŽ ¼ with the normal line OO as indicated by the 4th light ray in figure3.2. If medium II is a left-handed meta-material with à °Ã‚ Ã¢â‚¬ËœÃ¢â‚¬ º2 Figure 3.2 Passage of a light ray through the boundary between medium I with positive refractive index à °Ã‚ Ã¢â‚¬â„¢Ã‚ Ãƒ °Ã‚ Ã… ¸Ã‚ >0 and medium II with refractive index à °Ã‚ Ã¢â‚¬â„¢Ã‚ Ãƒ °Ã‚ Ã… ¸Ã‚ . The phase velocity expression à °Ã‚ Ã…“-à °Ã‚ Ã¢â‚¬ËœÃ‚ =à °Ã‚ Ã¢â‚¬ËœÃ‚ Ãƒ °Ã‚ Ã¢â‚¬ËœÃ¢â‚¬ º à °Ã‚ Ã…“† shows that the phase velocity à °Ã‚ Ã…“-à °Ã‚ Ã¢â‚¬ËœÃ‚  is related to the index of refraction , here c denotes the speed of light in a vacuum. For LHM has negative refractive index (à °Ã‚ Ã¢â‚¬ËœÃ¢â‚¬ º à °Ã‚ Ã…“† Figure 3.3: The energy flow and group velocity propagate forward in LHMs but the phase velocity is backward Veselago also predicted that the Doppler and Cerenkov effects will be reversed in LHM. An approaching source will appear to radiate at a lower frequency and charged particles moving faster than the speed of light in the medium will radiate in a backward cone, not a forward cone. These two exotic properties are not employed in this Dissertation, however details about them can be found in. LEFT-HANDED METAMATERIAL STRUCTURE The first LHM structure consists of split ring resonator (SRR) and thin wire (TW) or capacitance loaded strip (CLS)[19]. The SRR exhibits the negative value of permeability and the CLS and TW exhibit the negative value of permittivity in a certain range of frequency. Split Ring Resonator (SRR) (b) Figure 3.4: (a) Circular split ring resonator and (b) Square split ring resonator A split ring resonator (SRR) as shown in figure3.4 is part of the LHM structure that exhibit negative value of permeability. If the excitation of the magnetic field is perpendicular to plane of the structure, this will generate the magnetic dipole moment. The SRR is a highly conductive structure in which the capacitance between the two rings balances its inductance . The SRR induces high current density structure which creates a large magnetic moment. Capacitance Loaded Strip (CLS) and Thin Wire (TW) (a) (b) Figure 3.5: (a) Capacitance loaded strip (CLS) and (b) Thin wire (TW) figure 3.5(a) shows the capacitance loaded strip (CLS) and figure 3.5(b) shows the thin wire (TW). CLS and TW would produce strong dielectric like response. As electric field propagates parallel through the TW or CLS, it will induce a current along them. This will generate an electric dipole moment to the structure and exhibit a plasmonic-type of permittivity frequency . CST SOFTWARE CST was founded in 1992 byThomas Weiland. The main product of CST is CST STUDIO SUITE,which comprises A various modules dedicated to specific application areas. There are modules for microwave RF applications, summarized in CST MICROWAVE STUDIO, low frequency (CST EM STUDIO), PCBs and packages (CST PCB STUDIO), cable harnesses (CST CABLE STUDIO), temperature and mechanical stress (CST MPHYSICS STUDIO) and for the simulation of the interaction of charged particles and electromagnetic fields (CST PARTICLE STUDIO). All modules are integrated with a system and circuit simulator (CST DESIGN STUDIO). The version is CST Microwave Studio 2010. Figure 3.6 CST Microwave Studio In next chapter, the design of the LHM is discussed and the procedure in the simulation of the LHM using CST software is elaborated thoroughly. Besides that, the design of the Metamaterial structures, patch Microstrip antennas are also elaborated. CST Microwave Studio is a fully featured software package for electromagnetic analysis and design in the high frequency range. It simplifies the process of inputting the structure by providing a powerful solid modeling front-end which is based on the ACIS modeling kernel. Strong graphic feedback simplifies the definition of Your device even further. After the component has been modeled, a fully automatic meshing procedure (based on an expert system) is applied before the simulation engine is started. The simulators feature the Perfect Boundary Approximation (PBAâ„ ¢ method) and its Thin Sheet Technique (TSTâ„ ¢) extension, which increases the accuracy of the simulation by an order of magnitude in comparison to conventional simulators. Since no method works equally well in all application domains, the software contains four different simulation techniques (Transient solver, Frequency domain solver, Eigenmode solver, Modal analysis solver) which best fit their particular applicat ions. The most flexible tool is the transient solver, which can obtain the entire broadband frequency behavior of the simulated device from only one calculation run (in contrast to the frequency stepping approach of many other simulators). This solver is very efficient for most kinds of high frequency applications such as connectors, transmission lines, filters, antennas and many more.

The Little Foxes by Lillian Hellman :: play, marxism,

Throughout the play The Little Foxes by Lillian Hellman, the influence of Marxism is commonly displayed. The Hubbard’s are portrayed as constantly going against the social conforms that would be set in a Marxist society. They each pursue wealth or a social status. For what they covet, they go above and beyond to obtain. In the process they hurt other people. They each sacrifice their integrity to gain this wealth and status. Hellman’s title highlights the opposition of Marxism that is portrayed in the play. The title of the play comes from the bible. In that portion referred to it states that the foxes, which are represented by the Hubbard’s, will destroy the glory of the new south because their greed for power is so great. (Watson 173). The Hubbard’s all destroy each other for money. They want to build a cotton factory where costs are cheep and they make a lot of profit. However, to achieve this they have to step on many people toes and exploit workers (Hellman 159). Regina’s determination to gain wealth was unwavering. She let her husband die because he was not going to report her brothers for stealing his bonds. Regina then turns on her brothers and demands a greater percentage of the money since she can destroy them because they stole Horace’s bonds. To Regina, money means freedom to escape and go to the south where social standing is measured by the cloths and jewelry you have. This is against Marxist society because Marxists believe that everyone should be equal in money and standing (Hamilton 172). Regina wants to go to Chicago and Paris but in the process she lets her husband die and looses the love of Alexandra (Galens 165). She now has the option to have the bright, flamboyant social life she wanted but she can only have it alone now. Ben Hubbard has cheated and manipulated to gain his wealth. In the play Regina states that Ben has cheated so many men to get where he is now that his reputation is ruined around the area. Ben has no need for money; he ultimately wants to remain childless and wifeless. Thus, his desire for money is solely for a capitalist purpose. He is only interested in build his empire (Hamilton 172). To build his empire he needs to land a deal with Marshall. To do so he tries to make a big point of how much better his father rules Birdy’s family’s plantation and the differences between old southern aristocracy and new one.

Burt’s bee – an American company

Burt’s bee is an American company that deals into personal care products. It has differentiated its self on the basis of ‘Earth Friendly, Natural Personal Care Company’. Their products are being made from beeswax, natural oils, herbs and minerals (Smith, Dulcinea Norton, 2008, March). This company begun its operations in the year 1984 when Roxanne Quimby and Burt Shavitz an ex-couple living in Maine started making candles. They were made from they by-product of beeswax obtained from Burt’s honey business. This invention made sale up to $20,000 by the end of first year. Soon they product earned recognition and got orders form a boutique in New York. They added many organic beauty products to expend this line. In the year 1991 they added their best seller product lip balm. Soon they discontinued their famous candle production and concentrated on personal care items. Currently their product line includes face, body, men’s grooming, baby care, hair, lip care and outdoor remedies product. Their products are being sold in different countries of the world including United States, United Kingdoms, Canada, Ireland, Hong Kong and Taiwan. Retail Experiment Burt’s bee distinguished itself on the basis of organic and eco friendly products. It created a niche for it’s product by targeting people who are more inclined towards purchasing and using less chemical oriented products. Retail business can be explained as sale of goods or merchandises directly to customers through a fixed point. Availability of logistics and expansion plans play a vital role in deciding either a company should move into retail business or not. When a profit bearing company like Burt’s Bee plans to expand its operation they have to make an appearance in shelves of different departmental stores, malls, grocery stores even drug stores to be more visible over other competitor products. Making such strong appearance is not possible by limiting it’s self to being a manufacturer and a direct seller. Looking at online shopping websites (which is also a part of retail business) it brings products at a click of one button. It also saves human resource and middle man profit. It gives endless shelf-space to a manufacturer to display its products. Burt’s bee was already selling their product through QVC and making handsome amount of profit on it. It was time to get into physical retail business to increase their profitability. Retail business has many different advantages. If one person is out to buy grocery for home might also want to purchase any product that he sees on shelves. We all try to experiment with new products. This experimental nature is at peek when we go out of the house to do a week’s shopping. Instead of going at one particular shop to buy a specific product we all prefer one place stop that has all the products. It’s an era of expediency and we enjoy taking advantage of it. Retail business aids in saving time for a lot of customers. People are so busy in their personal and professional lives they prefer buying all what they need from one places rather than visiting different shops for specific products. Retail business also gives an edge over all those strong products available only at their dedicated shops. Their presences can be easily overlapped with a product that is available at every nook and corner. People usually go out with friends to malls for shopping. Strong word of mouth can also play a heavy role in increasing sales. Burt’s bee has a reputable name in the market and a loyal set of customers. Changing brand habit should not be a difficult task for them once the presence of their product becomes prominent. Appearance of Roxxane Quimby at different retail shops once in a while will add to customer satisfaction. When she started the business by selling beeswax candle she realized that most of her customers looked at the bottom of it to check its finishing. Costumers are very particular about quality maintenance. Heavy marketing can attract more customers to meet the proud owner of the product they are using. The fear of being discontinued from the end users can also be minimized through this strategy. This can also be done through comment cards. People can fill them and send it to her to give her. Retail business enables a customer to compare products at the location. This comparison can be made on the basis of ingredients, prices and packaging. Burt’s bee has the competitive advantage of being organic and less chemically treated product over others. It has gain popularity for being made from natural oils unlike other products available in the market. Conclusion Thus opting for a retail business will help them achieve desired target in a given time period. It becomes difficult to be a direct seller and expend to different countries. Though sales and revenues increase can not be separated from good marketing campaign. Promotion incentives like free samples can also be used to help purchase of new products and attract more customers. Heavy ATL (Above The Line) and BTL (Below The Line) marketing can also increase product awareness and spread the brand name amongst non users. Product availability will have a proportionate effect on increase sales. With higher demand price can also be increased. People are ready to pay a high amount but do not believe in compromising in quality. They will always choose convenience of purchasing ten things from one shop then roaming around 10 shops to buy one thing.

Architecture of the Rich and Famous in Palm Springs

Mid-Century or Midcentury? Any way you spell it (and both are correct), the modern designs of world class architects from the middle part of the 20th century continue to define Palm Springs, California. Nestled in the Coachella Valley and surrounded by mountains and deserts, Palm Springs, California is only a few hours drive from the bustle and tinsel of Hollywood. As the entertainment industry enveloped the Los Angeles area during the 1900s, Palm Springs became a favorite getaway for the many starlets and socialites who were making money faster than they could spend it. Palm Springs, with its abundant year-round sunshine, became a refuge for a game of golf followed by cocktails around the swimming pool — a fast-lane lifestyle of the rich and famous. The 1947 Sinatra House, with a swimming pool shaped like a grand piano, is but one example of the architecture from this period. Architectural Styles in Palm Springs The building boom in the United States after World War II enticed LA architects to Palm Springs — architects go where the money is. Modernism had taken hold throughout Europe and already immigrated to the US. Southern California architects adapted ideas from the Bauhaus movement and the International Style, creating an elegant yet informal style that is often called Desert Modernism. As you explore Palm Springs, look for these important styles: Desert ModernismArt ModerneSpanish EclecticGoogieTiki Fast Facts: Palm Springs Every year Modernism Week celebrates the many mid-century modern houses in Palm Springs, located about 100 miles (2 hours) east of Los Angeles, California.Original settlers were Cahuilla Native Americans, called Agua Caliente or hot water by Spanish explorers.California became the 31st state in 1850. U.S. surveyors first described the area of palm trees and mineral springs as Palm Springs in 1853. John Guthrie McCallum (1826-1897) and his family were the first white settlers in 1884.The Southern Pacific Railroad completed an East/West line in 1877 — the railroad owned every other square mile surrounding the tracks, creating a checkerboard of property ownership seen today.Palm Springs became a health resort, its mineral springs a sanitorium for the treatment of tuberculosis.Palm Springs was incorporated in 1938. Singer/celebrity Sonny Bono was the 16th Mayor of Palm Springs from 1988 to 1992.As early as 1919, Palm Springs was used as a ready-made set for many Hollywood silent m ovies. It quickly became a playland for people in the movie industry, because of its proximity to LA. Even today Palm Springs is known as The Playground of the Stars. Architects of Palm Springs Modernism Palm Springs, California is a virtual museum of Mid-Century Modern architecture with possibly the worlds largest and best-preserved examples of elegant homes and landmark buildings constructed during the 1940s, 1950s, and 1960s. Here is a sampling of what youll find when visiting Palm Springs: Alexander Homes: Working with several architects, the George Alexander Construction Company built more than 2,500 homes in Palm Springs and established a modernist approach to housing that was imitated throughout the United States. Learn about Alexander Homes. William Cody (1916-1978): No, not Buffalo Bill Cody, but the Ohio-born architect William Francis Cody, FAIA, who designed many homes, hotels, and commercial projects in Palm Springs, Phoenix, San Diego, Palo Alto, and Havana. Check out the 1947 Del Marcos Hotel, the 1952 Perlberg, and the 1968 St. Theresa Catholic Church. Albert Frey (1903-1998): Swiss architect Albert Frey worked for Le Corbusier before moving to the United States and becoming a Palm Springs resident. The futuristic buildings he designed launched the movement that became known as Desert Modernism. Some of his must-see buildings include these: 1949-1963 (with Robson Chambers): Tramway Valley Station1957 (with John Porter Clark, Robson Chambers, and E. Stewart Williams): Palm Springs City Hall1963: Frey House II1963-1965 (with Robson Chambers): Tramway Gas Station, now the Palm Springs Visitors Center John Lautner (1911-1994): Michigan-born architect John Lautner was an apprentice to Wisconsin-born Frank Lloyd Wright for six years before establishing his own practice in Los Angeles. Lautner is known for incorporating rocks and other landscape elements into his designs. Examples of his work in Palm Springs include: 1968: The Arthur Elrod House1979: The Bob and Delores Hope House Richard Neutra (1892-1970): Born and educated in Europe, Austrian Bauhaus architect Richard Neutra placed dramatic glass and steel homes in rugged California desert landscapes. Neutras most famous home in Palm Springs are these: 1937: Grace Lewis Miller House, the winter home of the St. Louis socialite1946: Kaufmann House, the same Kaufmanns who commissioned Frank Lloyd Wright in 1935 to build Fallingwater in Pennsylvania Donald Wexler (1926-2015): Architect Donald Wexler worked for Richard Neutra in Los Angeles, and then for William Cody in Palm Springs. He partnered with Richard Harrison before establishing his own firm. Wexler designs includes: 1961-1962: Steel Development Houses constructed by the Alexander Construction Company1961-1962: The Royal Hawaiian Estates, tiki style condominium complex in Palm Springs1965: Palm Springs Airport Original Terminal Building Paul Williams (1894-1980): Los Angeles architect Paul Revere Williams designed more than 2000 homes in southern California. He also designed: 1937: International Style clubhouse for the Tennis Club on Baristo Road, Palm Springs1954: Lucille Ball and Desi Arnaz home E. Stewart Williams (1909-2005): The son of Ohio architect Harry Williams, E. Stewart Williams built some of Palm Springs most significant buildings during a long and prolific career. Must-see: 1947: House for Frank Sinatra1954: The Edris House1960: Coachella Valley Savings and Loan (now Washington Mutual)1963: Tramway Upper Station1976: Palm Springs Desert Museum (now the Palm Springs Art Museum) Lloyd Wright (1890-1978): Son of the famous American architect Frank Lloyd Wright, Lloyd Wright was trained in landscape design by the Olmsted brothers and worked with his famous father developing the concrete textile block buildings in Los Angeles. Lloyd Wrights projects in and near Palm Springs include: 1923: Oasis Hotel, a distinctive Art Deco building with a 40-foot tower. Desert Modernism Near Palm Springs: Sunnylands, 1966, in Rancho Mirage, by architect A. Quincy Jones (1913-1979) Travel to Palm Springs for the Architecture As the center of Mid-Century Modernism, Palm Springs, California hosts many architecture conferences, tours, and other events. Most famous is Modernism Week held in February each year.   Several beautifully restored hotels in Palm Springs, California recreate the experience of mid-twentieth century living, complete with reproduction fabrics and furnishings by major designers of the period. The Chase HotelStudio rooms that recreate the 1950s.The Orbit InTwo sister inns, the Orbit In and the Hideaway, with a retro flair.RendezvousNostalgic 1950s theme rooms and gourmet breakfasts. Hotel History and DetailsLHorizon HotelDesigned by William Cody in 1952. Hotel History and DetailsThe Movie Colony HotelDesigned by Albert Frey in 1935. Hotel History and DetailsThe Monkey Tree HotelA 16-room restored boutique hotel designed in 1960 by Albert Frey. Sources History, City of Palm Springs, CA