ELECTROMAGNETICS APPLICATION. Coaxial cable.

Slides:



Advertisements
Similar presentations
Light and the Electromagnetic Spectrum. Light as a Wave light is a visible form of energy most of the energy that surrounds us is invisible this energy.
Advertisements

Transmission Media T.Najah Al-Subaie Kingdom of Saudi Arabia
Computer Communication & Networks
CH. 4 Transmission Media.
PH0101 Unit 2 Lecture 4 Wave guide Basic features
Example: Diamond in air What is the critical angle  c for light passing from diamond (n 1 = 2.41) into air (n 2 = 1)? Rearranging.
Intrinsically smart cement-matrix composites Topic 5.
Transfer Functions in EMC Shielding Design
1 The Science and Engineering of Materials, 4 th ed Donald R. Askeland – Pradeep P. Phulé Chapter 20 – Photonic Materials.
Electromagnetic applications Topic 6. Reading assignment Chung, Composite Materials, Ch. 5. No. 81 under “Publications – carbon” in website
Chapter 5 Basic properties of light and matter. What can we learn by observing light from distant objects? How do we collect light from distant objects?
Fibre Composite Electromagnetic Interference Shielding Materials for use in Airborne Vehicles Presented by Adrian Berghorst School of Mechanical Engineering.
Ultra-Lightweight Stainless Steel Micro-Filament EMI/RFI Braid.
Prof. David R. Jackson ECE Dept. Fall 2014 Notes 30 ECE 2317 Applied Electricity and Magnetism 1.
Prof. Ji Chen Notes 14 Transmission Lines (Radiation and Discontinuity Effects) ECE Spring 2014.
SIMS-201 Wire and Fiber Transmission Systems. 2  Overview Chapter 15 Wire and Fiber Transmission Systems Wire as a transmission medium Fiber optics as.
Sistem Jaringan dan Komunikasi Data #3. Overview  guided - wire / optical fibre  unguided - wireless  characteristics and quality determined by medium.
© 2010 Pearson Education, Inc. Light and Matter: Reading Messages from the Cosmos.
Engr Fundamental Ideas.
Materials - Metals Ken Youssefi PDM I, SJSU.
Physical Transmission
Nonferrous Alloys. l Aluminum Alloys l Magnesium and Beryllium Alloys l Copper Alloys l Nickel and Cobalt Alloys l Titanium Alloys l Refractory and Precious.
What determines a materials physical, chemical and mechanical properties?
Elements & the Periodic Table Metals Chapter 3 Section 2.
Conductive Textiles Where Electronics Meet Textiles Workshop with Lynne Bruning and Troy Robert Nachtigall Sponsored by Spark Fun and PlugandWear Versione.
Introduction to Network (c) Nouf Aljaffan
Section 3.1: Wires, Cables, and Connectors Scott Glogovsky and Jonathon Sturm Scott Glogovsky and Jonathon Sturm.
Lecture 8 Cable Certification & Testing:. Cable Distribution Cable Distribution Equipment UTP (Unshielded Twisted Pair) UTP Cable Termination Tools UTP.
®®® Total EMC Products is the trademark of AMIC A MIC Advanced Materials & Integration Co., Ltd. http : / / WWW. AMIC. Co. Kr ISO 9001 /  EXSOB.
Categories of Materials Metals and Alloys Polymers Ceramics Composites.
Chapter 18 – The Electromagnetic Spectrum and Light
7.1 Chapter 7 Transmission Media Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Categories of Materials
OPTICAL FIBER COMMUNICATIONS. Optical Fibres Sheath 1 Sheath 2 Sheath 3 Aluminum Tape Strength Member Steal Wire Reinforcement.
PERIODIC TABLE Chapter Fifteen: Elements and the Periodic Table  15.1 The Periodic Table of the Elements  15.2 Properties of the Elements.
1 Chapter 16 – Composites: Teamwork and Synergy in Materials.
Chapter 16 – Composites: Teamwork and Synergy in Materials
LOSSES IN FIBER BY:Sagar Adroja.
Prof. David R. Jackson ECE Dept. Spring 2016 Notes 12 ECE 3318 Applied Electricity and Magnetism 1.
Grounding & Shielding Ved Prakash Sandlas Director General
Raman spectroscopy.
Electromagnetic waves and Applications Part III:
Electromagnetic applications
Conductors are materials in which electrons can move easily.
Metallic Bonds and Properties of Metals
Transmission Media.
William Stallings Data and Computer Communications 7th Edition
INTRODUCTION TO OPTICAL COMMUNICATION TECHNOLOGY
Applied Electricity and Magnetism
Notes 5 ECE Microwave Engineering
PHOTONS Bushong, Chapter 4.
Chapter 12 Case Studies: Hybrids
ENE 325 Electromagnetic Fields and Waves
Transfer Functions in EMC Shielding Design
OPTICAL PROPERTIES K L University Department of Physics.
Natural Sciences and Technology Grade 5
Light Investigate the properties and behaviors of mechanical and electromagnetic waves Explore and explain the nature of sound and light energy.
Thomas Young Young’s double-slit experiment (1801): provided concrete evidence for the wave nature of light.
Conductors & Insulators
Metals & Alloys, Plastics
Applied Electromagnetic Waves Notes 6 Transmission Lines (Time Domain)
Chapter 12 Case Studies: Hybrids
PDT 153 Materials Structure And Properties
How a Shield Works A shield contains or excludes electromagnetic energy by reflecting or absorbing the energy. Whenever EM energy passes from one medium.
monochromatic light source
Electricity 2 types of electricity
Notes 14 Transmission Lines (Discontinuity Effects)
Anything that can carry information from a source to a destination.
Transmission Media Located below the physical layer and are directly controlled by the physical layer Belong to layer zero Metallic Media i.e. Twisted.
PH0101 Unit 2 Lecture 4 Wave guide Basic features
Presentation transcript:

ELECTROMAGNETICS APPLICATION

Coaxial cable

Electromagnetic applications  Electromagnetic interference (EMI) shielding  Low observability (Stealth)  Electromagnetic transparency (radomes)

 Electronic enclosures (e.g., computers, pacemaker leads, rooms, aircraft, etc.)  Radiation source enclosures (e.g., telephone receivers)  Cell-phone proof buildings  Deterring electromagnetic form of spying

 Electronic pollution  Telecommunication  Microwave electronics  Microwave processing  Lateral guidance

Coaxial cable method of electromagnetic testing

Reflectivity R Fraction of energy of the electromagnetic radiation that is reflected

Absorptivity A Fraction of the energy of the electromagnetic radiation that is absorbed

Transmissivity T Fraction of the energy of the electromagnetic radiation that is transmitted

R + A + T = 1 The transmitted portion is the portion that has not been absorbed or reflected.

The attenuation in decibels (dB) is defined as Attenuation (dB) = 20 log 10 (E i /E), where E i is the incident field and E is the transmitted or reflected field. Note that E i > E.

©2003 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.

 Reflection  Absorption  Multiple reflection

Mainly due to interaction of electromagnetic radiation with the electrons in the solid

Skin Effect Phenomenon in which high frequency electromagnetic radiation interacts with only the near surface region of an electrical conductor

wheref = frequency,  = magnetic permeability =  0  r,  r = relative magnetic permeability,  0 = 4  x H/m, and  = electrical conductivity in  -1 m -1. Skin depth (  )

Due to interaction of electromagnetic radiation with the electric/magnetic dipoles, electrons and phonons in the solid

Material attributes that help shielding  Electrical conductivity  Magnetization  Electrical polarization  Small unit size  Large surface area

Table 5.1. Electrical conductivity relative to copper (  r ) and relative magnetic permeability (  r ) of selected materials. Material rr rr rrrr r/rr/r Silver1.051 Copper1111 Gold0.71 Aluminum0.611 Brass0.261 Bronze0.181 Tin0.151 Lead0.081 Nickel x Stainless steel (430) x Mumetal (at 1 kHz)0.0320, x Superpermalloy (at 1 kHz) ,0003,0003 x 10 -7

 Nanofiber is more effective than fiber, due to small diameter and the skin effect.  Thermoplastic matrix: nanofiber (19 vol.%) gives shielding 74 dB at 1 GHz, whereas fiber (20 vol.%, 3000 microns long) gives 46 dB.  Cement matrix: nanofiber (0.5 vol.%) gives 26 dB, whereas fiber (0.8 vol.%) gives 15 dB.

 Carbon fiber (400 microns long)  Nickel fibers (2 and 20 microns diameter)  Aluminum flakes

 Diameter: 0.4 micron  Carbon core diameter: 0.1 micron  Nickel by electroplating  87 dB at 7 vol.% (thermoplastic matrix)  Much better than uncoated carbon nanofiber and nickel fibers.

Table 1. Electromagnetic interference shielding effectiveness at 1-2 GHz of PES-matrix composites with various fillers FillerVol. % EMI shielding effectiveness (dB) Al flakes (15 x 15 x 0.5  m) 2026 Steel fibers (1.6  m dia. x 30 ~ 56  m) 2042 Carbon fibers (10  m dia. x 400  m) 2019 Ni particles (1~5  m dia.) Ni fibers (20  m dia. x 1 mm) 195 Ni fibers (2  m dia. x 2 mm) 758 Carbon filaments (0.1  m dia. x > 100  m) 732 Ni filaments (0.4  m dia. x > 100  m) 787

 Steel fiber (8 microns) 58 dB  Carbon fiber (15 microns) 15 dB  Carbon nanofiber (0.1 micron) 35 dB  Graphite powder (0.7 micron) 22 dB  Coke powder (less than 75 microns) 47 dB

 Steel fiber (8 microns) 40 ohm.cm  Carbon fiber (15 microns) 830 ohm.cm  Carbon nanofiber (0.1 micron) 12,000 ohm.cm  Graphite powder (0.7 micron) 160,000 ohm.cm  Coke powder (less than 75 microns) 38,000 ohm.cm

EMI gaskets  Shielding effectiveness  Resiliency

 Metal coated elastomers  Elastomers filled with conductive particles  Flexible graphite

 High specific surface area  Resilience  Conductive

Table 2 Tensile properties of carbon fiber epoxy-matrix composites. Standard deviations are shown in parentheses Fiber typeStrength (MPa)Modulus (GPa) Elongation at break (%) As-received718 (11)85.5 (3.8)0.84 (0.03) Epoxy coated626 (21)73.5 (4.4)0.85 (0.03)

Table 1 Attenuation under transmission and under reflection of carbon fiber composites. Fiber type Attenuation upon transmission (dB) Attenuation upon reflection (dB) As-received 29.6   0.2 Activated 38.8   0.2

 Design an aircraft that cannot be detected by radar.  We might make the aircraft from materials that are transparent to radar. Many polymers, polymer- matrix composites, and ceramics satisfy this requirement.  We might design the aircraft so that the radar signal is reflected at severe angles from the source.  The internal structure of the aircraft also can be made to absorb the radar. For example, use of a honeycomb material in the wings may cause the radar waves to be repeatedly reflected within the material.  We might make the aircraft less visible by selecting materials that have electronic transitions of the same energy as the radar.