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Fractal Antenna
This document provides an overview of fractal antennas and their advantages for wireless communications. Fractal antennas can achieve multiband operation and miniaturization by utilizing fractal geometry which increases the effective antenna length while maintaining a small size. Specific fractal designs like the Koch loop and Sierpinski monopole and dipole are discussed. Fractal antennas have the potential to develop small, low profile antennas for applications like wireless communications.
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Introduction to fractal antennas and objectives of the study on miniaturization techniques for wireless communications.
Discusses fractal antenna theory, its nature, and benefits such as multiband operation and miniaturization.
Describes the iterative mathematical process of fractal geometry used in antenna design with examples of specific fractals.
Visual examples of fractal structures like the Sierpinski and Koch fractals to exemplify theoretical points.
Explains how reduced length can lower resonant frequency through fractal geometry, achieving more compact antennas.
Describes how fractal antennas can operate on multiple frequency bands and the significance of current paths.
Details the advantages of fractal loop antennas regarding resonance and improved input impedance.
Explains the Sierpinski monopole and dipole, noting multiple bands and methods for predicting performance.
Discusses the configuration of fractal antenna arrays for improved gain and the features of periodic vs. random arrays.
Summarizes fractal antenna theory, highlighting potential developments in lightweight and compact antennas.
Introduction to GPS as a satellite-based positioning system and its potential issues due to misunderstanding.
Overview of GPS features including being free, precise, reliable, and describing its components: Space, Monitor, and User segments.
Mechanics of determining GPS positions using measurements from multiple satellites to narrow possible locations.
Discusses variables impacting GPS accuracy, including receiver design and satellite positioning known as PDOP.
Explains the Wide Area Augmentation System (WAAS) providing free differential GPS corrections for improved accuracy.
Identifies sources of errors affecting GPS such as PDOP, multipath effects, and SNR.
Common uses of GPS including navigation, GIS mapping, recreation, and future advancements in GPS technology.
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Fractal Antenna
- 1. FRACTALANTENNAS –A NOVEL MINIATURIZATIONTECHNIQUE FOR WIRELESS COMMUNICATIONS Prepared By : Patel Jay C ME(EC)-140870705004
- 2. OBJECTIVE To providea study of different fractal antenna with an overview of recent developments.
- 3. FRACTAL ANTENNA –AN INTRODUCTION Fractal antenna theory – a new area “fractal ” means broken or irregular fragments “Family of complex shapes that possess an inherent self similarity or self affinity in their geometrical structure” Came from unique occurances in nature
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- 5. FRACTAL ANTENNA Suggestssome attractive solutions for using single small antenna needed for different frequency bands (multiband operation) Size, area and mass reduction (miniaturization) The effective length of the antenna can be increased keeping the total area same
- 6. GEOMETRY OF FRACTALS The shape can be formed by iterative mathematical process called IFS Based on series of affine transformations w(x,y) = (ax+by+e, cx+dy+f) ○ a,b,c,d control rotation and scaling ○ e , f control linear translation Repeatedly applying W to the previous geometryfractal geometry A1=W(A0); A2 = W (A1);……..
- 7. GEOMETRY OF FRACTALS IFS generated a sequence that converges to a final image More no. of iterations increase in effective length decrease in resonant frequency Fractal geometry used in most of the works: Koch fractal Sirepinski fractal Koch island fractal
- 8. A three iterationSirepinski fractal A FOUR ITERATION KOCH FRACTAL
- 9. A THREE ITERATIONKOCH ISLAND
- 10. HOW MINIATURIZATION ? Achieving lower fr with reduced length is miniaturization. Fractal geometry comprise larger antenna length in a smaller volume.
- 11. HOW MULTIBAND OPERATION? A single antenna operating in two or more freuquency bands multiband operation Antenna elements operating in different frequency used In fractal antenna coupling between sharp angles produce different current paths achieving multi band operation
- 12. FRACTAL LOOP ANTENNAS Loop antenna needs more space Small loop low input resistance- mismatch to the transmission line
- 13. KOCH LOOP •A kochloop can be used loop antenna •Perimeter gets increased maintaining the same volume • less volume required for resonance • input impedance improved
- 14. SIREPINSKI MONOPOLE ANDDIPOLE Multiple bands controlled by scale factors Flare angle controls the frequency shift Models developed to predict the performance
- 15. FRACTAL ANTENNA ARRAY Antenna array : to improve the gain Random fractal used to generate array configuration between periodic and random Low side lobe (feature of periodic array ) Robust (feature of random array) four stage linear Cantor array
- 16. CONCLUSION An overviewof fractal antenna theory was presented. Small sized, lo profile and low weight antennas can be developed by using fractal geometries. Being in early stage of development more innovations to come in the future.
- 18. What is GPS? A very precise positioning system • Developed and maintained by the US Department of Defense (DOD) • Satellite Based * 24 satellites * 20,200 km high orbit
- 19. BUT! Although it isa very precise geographic positioning system •It is very easy to get youself into trouble •Why? •Because you (probably) don’t understand how it works •And that leads to garbage
- 20. Characteristics of GPS •Free • Precise • Reliable • Anytime & anywhere • All weather • Unlimited user capacity Almost!
- 21. Segments of GPS 1.Space Segment A constellation of 24 satellites 2. Monitor Station A network of earth-based facilities 3. Users & Equipment Source:Trimble
- 22. Segments of GPS 1.Space Segment A constellation of 24 satellites
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- 24. How GPS Works……… Uses measurements from 4+ satellites Distance = travel time x speed of light Source:Trimble
- 25. Determining GPS Position •Suppose the distance from Satellite A to our position is 11,000 miles • At this point we could be located anywhere on the specified sphere Satellite A + • Next, let us take another measurement from a second satellite, Satellite BSatellite B + • Now our position is narrowed down to the intersection of theses two sphere
- 26. Satellite C + Determining GPSPosition Satellite A Satellite B + + • Taking another measurement from a 3rd satellite narrows our position down even further, to the two points • So by ranging from 3 satellites we can narrow our position to just two points in space • These points are located where the 3rd sphere cuts through the the intersection of first two spheres
- 27. Satellite C + How dowe decide which one is our true location? Satellite A Satellite B + + • We could make a 4th measurement from another satellite to determine the true point • However, GPS receivers use a 4th satellite to precisely locate our position • We can eliminate one of the two points that gives a ridiculous answer • The ridiculous point may be too far from the earth OR
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- 29. How accurate isGPS? Depends on some variables • Design of receiver • Relative positions of satellites, technically known as PDOP (Position dilution of precision) • Postprocessing • Time spent on measurement
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- 31. GeoXT Versus Garmin Mostlyused for GIS data collection Mostly used for recreational purposes
- 32. How accurate isGPS? Depends on some variables • Design of receiver • Relative positions of satellites, often known as DOP (Dilution of Precision) • Postprocessing • Time spent on measurement
- 33. WAAS • Wide AreaAugmentation System. • It provides FREE GPS differential correction data for visible satellites. • Developed & operated by the FAA (Federal Aviation Administration) for flight navigation but it’s available free to GPS users. • WAAS-enabled receivers can provide sub-meter level accuracy anywhere in most locations of the US and southern Canada.
- 34. WAAS • Differential correctionsare computed from ground stations and then uploaded to geostationary satellites for broadcasting. • WAAS-enabled GPS receiver automatically uses such correction data to enhance the positional accuracy.
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- 36. Multipath • When GPSsignals arrive at the receiver having traveled different paths
- 37. What is aPDOP? • Position Dilution of Precision Good PDOP Poor PDOP
- 38. SNR (signal-to-noise ratio) •SNR determines the signal strength relative to noise • GPS position is degraded if the SNR of one or more satellites in the constellation falls below certain range Signal Strength Indicators
- 39. Common use ofGPS A. GIS data collection & mapping B. Navigation C. Recreation
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- 41. GPS for Navigation •GPS in PDA are getting popular in car comes with voice guidance.
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- 44. Future GPS A. GPSin USA B. GLONASS program from Russia C. GALILEO from European countries