Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Central States VHF Conference July 2007 San Antonio TX

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Electromagnetic Spectrum Basics Prof. H. Paul Shuch N6TX

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Electromagnetic Spectrum Basics H. Paul Shuch Visiting Professor of Physics and Astronomy Lycoming College

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Lesson Objectives Upon completion of this lesson, you will demonstrate mastery by: demonstrate mastery by: Deriving and recalling the speed of light Deriving and recalling the speed of light Identifying the frequencies and wavelengths Identifying the frequencies and wavelengths defining the RF, Microwave, and visible spectra defining the RF, Microwave, and visible spectra Converting between frequency and wavelength Converting between frequency and wavelength Knowing Planck's Constant from memory Knowing Planck's Constant from memory Calculating the energy and mass of a photon Calculating the energy and mass of a photon

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved All waves behave Fundamentally AlikeGauss Faraday Ampere

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved A continuum -- DC to Daylight... and Beyond!

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Visible Light Less than one octave

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved = Frequency: Cycles per Second (Hz) = Wavelength: Meters per Cycle

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved c =  Speed of Light

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved c =  (both equal 3 * 10 8 m/s!) Red: 750 nm * 400 THz Violet: 400 nm * 750 THz

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved (or three hundred kilometers per millisecond) (that’s three hundred million meters per second)

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved The long and the short of it The Rest of the Spectrum

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved The RF Spectrum LFLFLFLF EHEHFFEHEHFFFMFHF VHVHFFVHVHFFF UHUHFFUHUHFFF SHSHFFSHSHFFF VLFVLFVLFVLF ULFULFULFULF SLFSLFSLFSLF ELFELFELFELF

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved RF Frequencies LFLFLFLF EHEHFFEHEHFFFMFHF VHVHFFVHVHFFF UHUHFFUHUHFFF SHSHFFSHSHFFF VLFVLFVLFVLF ULFULFULFULF SLFSLFSLFSLF ELFELFELFELF Hz Hz Hz kHz kHz kHz MHz MHz MHz GHz GHz GHz

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved RF Wavelengths LFLFLFLF EHEHFFEHEHFFFMFHF VHVHFFVHVHFFF UHUHFFUHUHFFF SHSHFFSHSHFFF VLFVLFVLFVLF ULFULFULFULF SLFSLFSLFSLF ELFELFELFELF Mm Mm Mm km km km m m m cm cm mm  m) = 300 / (MHz)

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved KummLSCX 1 GHz 100 GHz 1 GHz 100 GHz LumpedComponentsDistributedComponents OpticalComponents Microwave Bands

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved KummLSCX GHz: Microwave Bands

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved KummLSCX cm:  cm) = 30 / (GHz) GHz: Microwave Bands

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Microwave Band’s Greatest Hits

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Actually, both! Photons: are they waves, or particles?

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Where h = * Joules * seconds Energy per Photon – Planck’s Law e = h

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Remember red light? energy per photon e = h * ν e = (6.626 * J * s) * (400 * cycles/s) e = 2.65 * Joules

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved How about violet? energy per photon e = h * ν e = (6.626 * J * s) * (750 * cycles/s) e = 4.97 * Joules

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved How much energy per visible photon? Less than a billionth of a billionth of a Joule!

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Sunlight falling on Earth: ~ 1 kW/m 2 (billions and billions of photons per second per square meter!)

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Left to right, Low to high energies The spectrum as An energy continuum

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Q: How are Photons like quick Catholics? A: They have relativistic mass!

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved (OK, so the rest mass of a photon is zero. However…) e = h and e = m c 2 so, h  = m c 2 and relativistic mass: m = h /c 2

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Let’s calculate relativistic mass for a red photon: m = h /c 2 = (6.626 * J * s) * (400 * Hz) (3 * 10 8 m/s) 2 = 2.94 * kg

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Is a red photon massive? (no, that’s only about a millionth of the mass of an electron!)

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Review Exercises

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved 1. What is the velocity of forward propagation of radiant electromagnetic energy in free space? c = 3 * 10 8 m/s

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved 2. From memory, what frequencies and wave- lengths define the edges of the visible light spectrum? = THz = THz = nm = nm

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved 3. What is the value of Planck's Constant? h = * J*s

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved 4. Interstellar hydrogen emits a strong spectral radiation line at a wavelength of 21 cm. To what frequency does this correspond? = c / = c / = 1420 MHz = 1420 MHz

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved 5. Interstellar hydrogen emits a strong spectral radiation line in which segment of the electromagnetic spectrum? 1420 MHz is in the UHF spectrum, which extends from 300 to 3000 MHz.

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved 6. Interstellar hydrogen emits a strong spectral radiation line in which microwave band? 21 cm is in L-band, which extends from 30 to 15 cm wavelength.

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved 7. Hydrogen line receiving equipment would be composed of which type of components? All microwave circuitry incorporates distributed components.

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved 8. How much energy is emitted by one hydrogen photon? e = h * ν e = (6.626 * J*s) * (1.420 * 10 9 Hz) e = 9.4 * Joules

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved 9. How much does that hydrogen photon weigh? m = h /c 2 = (6.626 * J * s) * (1.42 * 10 9 Hz) (3 * 10 8 m/s) 2 = 1.05 * kg

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved 10. What is the most important characteristic of all electromagnetic waves? They all behave fundamentally alike.

Copyright © 2007 by H. Paul Shuch, Ph.D.All Rights Reserved Did you score eight or higher? You’ve mastered spectrum basics!