1. Electromagnetic Radiation & Satellites Antenna Design Pete Arvedson California Science Conference October 26, 2013 Hosted by Satellite Educators Association Lesson plan development supported by a grant from NOAA-CREST West

2. Session Objectives  Relate wavelength and frequency  Construct 1/10 th scale model wave  Calculate antenna length  Apply to 5-element Yagi antenna design  Build 1/10 th scale antenna Satellite Educators Association California Science Conference 2013 Antenna Design - 2

3.  Solar radiation reaches Earth surface Satellite Educators Association California Science Conference 2013 Antenna Design - 3

4.   Surface features reflect solar radiation to remote sensors Satellite Educators Association California Science Conference 2013 Antenna Design - 4

5.    Satellite sends radio signal from remote sensors to Earth station Satellite Educators Association California Science Conference 2013 Antenna Design - 5

6. Wave Properties crest trough wavelength, λ (meters) amplitude How many waves pass a point each second = frequency, ν (1/sec or Hertz) Satellite Educators Association California Science Conference 2013 Antenna Design - 6

7. Electromagnetic Spectrum Satellite Educators Association California Science Conference 2013 Antenna Design - 7

8. Wave Properties c = speed of light = 299,792,458 m/s -in vacuum ~ 300 x 10 6 m/s -in metal = 280.225 x 10 6 m/s c λ ν c = λν λ = c / ν ν = c / λ Satellite Educators Association California Science Conference 2013 Antenna Design - 8

9.  POES WEFAX frequency = 137.50 MHz  λ = c / ν  λ = Wavelength from Frequency Satellite Educators Association California Science Conference 2013 Antenna Design - 9

10. Build Wave Model: 1/10 Scale 1 / 10 scale model wave: λ = 21.8 cm wavelength: λ = 2.18 m Satellite Educators Association California Science Conference 2013 Antenna Design - 10

11. Antenna Size – First Look  EMR energy resonates in antenna metal wire producing current  Antenna length should match radio signal wavelength  Wavelength for 137.5MHz = 2.18 m  ½ or ¼ wavelength is best!  2.18 / 2 = 1.09 m Satellite Educators Association California Science Conference 2013 Antenna Design - 11

12. Antenna Size - Actual 2.182 m ½ wavelength = 1.019 m 1 / 10 scale model antenna length = 10.19 cm 2.038 m Satellite Educators Association California Science Conference 2013 Antenna Design - 12

13. Yagi Antenna  1926 Hidetsugu Yagi & Sintaro Uda Tohoku Imperial University, Japan  Driven element; parasitic directors & reflector  Highly directional & wavelength selective Satellite Educators Association California Science Conference 2013 Antenna Design - 13

14. Brent Stirton, http://ngm.nationalgeographic.com Satellite Educators Association California Science Conference 2013 Antenna Design - 14

15. Design Your Antenna 3.0 cm 8.74 cm 92.0 cm 9.20 cm 96.8 cm 9.68 cm 10.19 cm 112.1 cm 11.21 cm 87.4 cm 4.1 cm 18.3 cm Satellite Educators Association California Science Conference 2013 Antenna Design - 15

16. Extension  Build scale models other antenna types  Calculate antenna length for 1693 MHz  Build several real antennas & determine which is best for satellite reception  Compare/Contrast crossed Yagi with QHA  Build chicken wire parabolic reflector Satellite Educators Association California Science Conference 2013 Antenna Design - 16

17. CA Science Standards  Grades 9-12: Physics 4.Waves have characteristic properties that do not depend on the type of wave (a, c, e) 5.Electric and magnetic phenomena are related and have many practical applications (e, f, h)  Grades 9-12: I & E 1.Scientific progress is made by asking meaningful questions and conducting careful investigations (a, d, g) Satellite Educators Association California Science Conference 2013 Antenna Design - 17

18. Contact Information  Pete Arvedson - arvedson@aol.com  Check out lesson plans in Satellite Educators Association (SEA) monthly Newsletter… http://www.SatEd.org  More opportunities to involve students doing research: SEA’s M.Y. S.P.A.C.E.* Program - an international high school collaborative environmental research program using satellite-based data… http://www.calstatela.edu/programs/crest/ * (Multinational Youth Studying Practical Applications of Climatic Events) Satellite Educators Association California Science Conference 2013 Antenna Design - 18