1 / 19

Comparison of Cantenna and Printed Dipole Array Antennas in Homebrew Applications

This analysis delves into two styles of homemade antennas, focusing on electromagnetic theory basics and practical aspects such as fabrication, beam characteristics, field patterns, and testing. Explore the advantages and drawbacks of classic dipole antennas and the modern Printed Dipole Array while touching on key factors like antenna strength, portability, and fabrication ease.

lbaxter
Download Presentation

Comparison of Cantenna and Printed Dipole Array Antennas in Homebrew Applications

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Analysis of 2 Styles of Homebrew Antennas

  2. Electromagnetic theory basics • Classic Dipole Analysis

  3. How big should our antennas be? • frequency range 2.45GHz • Lambda * frequency = speed of light • Lambda = (3e8m/s)/(2.45e9s^-1) • Lambdba = 0.122m or 4.8in

  4. The “Cantenna” • The first type of antenna and very common in the Homebrew world is the can-based antenna or cantenna. • Fabrication Parts • Can • Piece of standard 50ohm wire • N-type connector

  5. Fabrication leads to:

  6. So what does a cantenna radiation beam look like?

  7. Printed Dipole Array • This uses antenna strip idea as opposed to hollow conductive waveguides to do its work. • Fabrication • Glass substrate • Adhesive copper roll • Vinyl cutter

  8. Fabrication leads to

  9. Recognizing the dipole array • multiple dipoles squeezing beam and increasing gain

  10. Dipole Array E&M field patterns

  11. Why the tapered feed line (balun)? • Balance/unbalance transmission line for VSWR characteristics

  12. The Printed Dipole Array Antenna beam?

  13. Which is the better antenna? VS.

  14. Field Testing • Duplicate parameters of cantenna test found online and compare results • 1320ft Line of Sight distance • Standard dipole on AP/Source/tx • Laptop using plug-in card for destination/rcvr Laptop w/card Top of vassar parking structure 1320 ft Access Point/source Roof of my home

  15. Cantenna test results • http://home.carolina.rr.com/harothberg/Test2.htm • Control: only using pc and wireless card • Signal Level: -89dBm -> 1.26e-12W • Actual test: using can design • Signal Level: -68dBm -> 1.58e-10W • dBi = log[base 10](P1/P2) • 2.1dBi when compared to power from card

  16. Printed Dipole Array Test Setup • Views from Source/AP and Destination/Laptop 1320 ft: laptop site on Vassar parking 1320 ft: AP on home roof

  17. Printed Dipole Array Test Results • Control: only using pc and wireless card • Signal Strength Level: -91dB • Actual test: using printed dipole array design • Signal Strength Level: -65dB • dBi = log[base 10](P1/P2) • 2.6dBi when compared to power from card Wireless Card Printed Dipole Array

  18. Test Results Findings • Absolutes [Cantenna vs. P.D.] • Antenna Strength: 2.1dBi vs. 2.6dBi • Surprise results of holding P.D antenna with and without one’s hand: • An unintended experiment happened as the antenna was being tested. One test run involved me holding the antenna with my hand (accidentally), while the other involved me holding the antenna in a nonconducting paper bag. • Antenna gain showed a relative increase of +9dB in the signal when no hands were used to hold the antenna. That is a 3 time doubling of power in the signal. These results simply stress the significant affect biological contact can have on performance and points to better ways of insulating the printed dipole antenna from conductive influences.

  19. The better antenna, based on analysis: • Gain/power and coverage • P.D.: 3 dipoles focused in 1D • great gain and coverage, good for community setting • Can: has 1 dipole that is focused in 2D • okay on gain, low on coverage, good for point to point • Fabrication • P.D.: mass production easier • Can: one-off production easier • Portability • P.D.: low profile(2D), lightweight, durable • Can: bulky(3D), lightweight, durable

More Related