Antennas slideshare part 1
- 1. Dr. S.MUTHUMANICKAM Associate Professor Department of ECE 1 EC8701 ANTENNAS AND MICROWAVE ENGINEERING PART I
- 2. Bloom's Taxonomy 2 Generating and producing knowledge Differentiating, organizing and attributing knowledge Able to understand well enough to give examples, interpret, classify, summarize, infer, compare, or explain knowledge Checking and critiquing information Executing and implementing knowledge zing and recalling facts, processes, and patterns
- 3. ANTENNAS MICROWAVES UNIT V MICROWAVE DESIGN PRINCIPLES SYLLABUS UNIT III ANTENNA ARRAYS AND APPLICATIONS ANTENNAS AND MICROWAVE ENGINEERING UNIT IV PASSIVE AND ACTIVE MICROWAVE DEVICES UNIT I INTRODUCTIO N TO MICROWAVE SYSTEMS AND ANTENNAS UNIT II RADIATION MECHANISMS AND DESIGN ASPECTS 3
- 4. OBJECTIVES: •To enable the student to understand the basic principles in antenna and microwave system design •To enhance the student knowledge in the area of various antenna designs •To enhance the student knowledge in the area of microwave components and antenna for practical applications 4
- 5. OUTCOMES: The student should be able to: • Apply the basic principles and evaluate antenna parameters and link power budgets • Design and assess the performance of various antennas • Design a microwave system given the application specifications TEXTBOOKS: 1. John D Krauss, Ronald J Marhefka and Ahmad S. Khan, "Antennas and Wave Propagation: Fourth Edition, Tata McGraw-Hill, 2006. (UNIT I, II, III) 2. David M. Pozar, "Microwave Engineering", Fourth Edition, Wiley India, 2012.(UNIT I,IV, V) REFERENCES: 1. Constantine A. Balanis, ―Antenna Theory Analysis and Design‖, Third edition, John Wiley India Pvt Ltd., 2005. 2. R.E.Collin, "Foundations for Microwave Engineering", Second edition, IEEE Press, 2001 5
- 6. UNIT I INTRODUCTION TO MICROWAVE SYSTEMS AND ANTENNAS EM Spectrum Microwave frequency bands What is an Antenna? Why Antennas? Physical concept of radiation Radian and Steradian Antenna Beam Solid Angle Isotropic Radiator Fields and Power Radiated by an Antenna Antenna Pattern Characteristics Front to Back Ratio(FBR) Antenna Beam Efficiency Radiation Power density Radiation Intensity Directivity Gain and Gain measurements 6
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- 8. In 1886, Heinrich Hertz developed a wireless communication. He used a loop antenna as a receiver, and observed a similar disturbance. By 1901, Marconi was sending information across the Atlantic. A painting of Michael Faraday. Being a great experimentalist, he naturally dabbled in chemistry, shown here. 8
- 9. λ=c/f, where λ is wavelength, c is velocity of light, f is operating frequency 9
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- 11. Designati on Frequency range Wavelength range Typical uses L band 1 to 2 GHz 15 cm to 30 cm military telemetry, GPS, mobile phones (GSM), amateur radio S band 2 to 4 GHz 7.5 cm to 15 cm weather radar, surface ship radar, and some communications satellites (microwave ovens, microwave devices/communications, radio astronomy, mobile phones, wireless LAN, Bluetooth, ZigBee, GPS, amateur radio) C band 4 to 8 GHz 3.75 cm to 7.5 cm long-distance radio telecommunications X band 8 to 12 GHz 25 mm to 37.5 mm satellite communications, radar, terrestrial broadband, space communications, amateur radio, molecular rotational spectroscopy Ku band 12 to 18 GHz 16.7 mm to 25 mm satellite communications, molecular rotational spectroscopy K band 18 to 26.5 GHz 11.3 mm to 16.7 mm radar, satellite communications, astronomical observations, automotive radar, molecular rotational spectroscopy Ka band 26.5 to 40 GHz 5.0 mm to 11.3 mm satellite communications, molecular rotational spectroscopy Q band 33 to 50 GHz 6.0 mm to 9.0 mm satellite communications, terrestrial microwave communications, radio astronomy, automotive radar, molecular rotational spectroscopy U band 40 to 60 GHz 5.0 mm to 7.5 mm V band 50 to 75 GHz 4.0 mm to 6.0 mm millimeter wave radar research, molecular rotational spectroscopy and other kinds of scientific research W band 75 to 110 GHz 2.7 mm to 4.0 mm satellite communications, millimeter-wave radar research, military radar targeting and tracking applications, and some non-military applications, automotive radar F band 90 to 140 GHz 2.1 mm to 3.3 mm SHF transmissions: Radio astronomy, microwave devices/communications, wireless LAN, most modern radars, communications satellites, satellite television broadcasting, DBS, amateur radio D band 110 to 170 GHz 1.8 mm to 2.7 mm EHF transmissions: Radio astronomy, high-frequency microwave radio relay, microwave remote sensing, amateur radio, directed-energy weapon, millimeter wave scanner Microwave frequency bands 11
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- 13. 13 Antennas in snail ANTENNA IN BIOLOGY
- 14. ANTENNA 1. A piece of conducting material in the form of a wire, rod or any other shape with excitation. 2. A source(Rxr) or radiator(Txr) of electromagnetic waves. 3. A sensor of electromagnetic waves. 4. A transducer. 5. An impedance matching device. 6. A coupler between a generator and space or vice-versa. 14
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- 19. Charge uniformly distributed in a circular cross section cylinder wire In summary: 1.If a charge is not moving, current is not created and there is no radiation. 2. If charge is moving with a uniform velocity: a. There is no radiation if the wire is straight, and infinite in extent. b. There is radiation if the wire is curved, bent, discontinuous, terminated, or truncated, as shown in Figure. 3. If charge is oscillating in a time-motion, it radiates even if the wire is straight. Physical Concept of Radiation 19
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- 23. 23 Steradian
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- 27. ANTENNA BEAM SOLID ANGLE Side lobes are included for calculations 27
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- 29. 29 Problem
- 30. POWER FROM AN ISOTROPIC RADIATOR 30
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- 34. 34 FIELD PATTERN POWER PATTERN Emax/√2 Pmax/2
- 36. 36 FBR = 1 FBR > 1 Bidirectional Pattern Unidirectional Pattern FRONT TO BACK RATIO
- 37. 37 TYPICAL VALUES OF ANTENNA PARAMETERS
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- 41. 41 DIRECTIVITY OF ANTENNA 4п = solid angles for sphere Max. directivity of a current element
- 42. 42 Antenna Pi Pr Pr = η Pi 0< η < 1 η is radiation efficiency GAIN OF ANTENNA Gain = U(θ,φ) Input power accepted 4п
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- 44. 44 GAIN MEASUREMENTS dBm = 10 x log (P/1 mw) Where P is power in watts
- 45. 45 POLAR GRAPH LOGARITHMIC GRAPH
- 46. 46 30dB is 32 x times more than 15 dB
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