Presentation on theme: "Exploring Antennas Van Warren AE5CC. Exploring Antennas: Pattern D esign S imulate M easure R efine."— Presentation transcript:
Exploring Antennas Van Warren AE5CC
Exploring Antennas: Pattern D esign S imulate M easure R efine
Exploring Antennas: Rule 1 Don’t reinvent the wheel. Explore and understand successful designs before inventing new ones.
Exploring Antennas: 2m Middle of band is 146 MHz Middle of CW band is MHz Single Most Important Parameter: Wavelength
Exploring Antennas: 2m Middle of band is 146 MHz 146 MHz = meters = 6.7 feet = inches Full Wavelength
Exploring Antennas: 2m General Purpose 2m Antenna in free space.
Exploring Antennas: 2m General Purpose 2m Antenna with Ground Plane (-5 Hz shift)
Exploring Antennas: 2m General Purpose Ground Plane Antenna.
Exploring Antennas: 2m General Purpose Antenna at 144 MHz In Free Space
Exploring Antennas: 2m General Purpose Antenna with Ground Plane at 144 MHz
Exploring Antennas: 2m Same Antenna at 900 MHz (33 cm band).
Exploring Antennas: Loops Now duplicate argument using tetrahedral geometry reasoning from the simplex argument and minimal materials and tesselation of sphere for balloon borne 2m antenna. Also reduce to ¼ wave and compare gain with full wavelength cases.
Total 20 MHz Results suggest a wire loop Can be “aimed” by simply Changing the feed point. Suggests a new radar antenna. Stationary loop, moving feed point. What is radiative efficiency? “Large” Circular loop has relatively flat frequency response, but surprisingly, high directionality! (front/side ratio) This borders on discovery! Compare with microphone gain patterns and yagi’s or “beam” antennas.
Need a program that will let me preprogram a series of mouse positions, clicks and key presses, to create animations of the gain patterns of these loop antennas. These are necessary and wonderful animations.