Welcome to the new FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
If you are having a problem, please check the Help Center for known solutions.
Need technical support from FlexRadio? It's as simple as Creating a HelpDesk ticket.

The BatBeam Project

2»

Comments

  • W9OY
    W9OY Alpha Team Member ✭✭
    edited February 2017
    Make the antenna change its shape between RX and TX.  Max pattern for RX max gain for TX.  This therefore would not be a freq agile antenna but a pattern agile antenna 

    73  W9OY
  • Rick - W5FCX
    Rick - W5FCX Member ✭✭
    edited January 2017
    Interesting idea, Lee. Can you elaborate with an example of what shape change would provide hugher RX gain that TX?
  • W9OY
    W9OY Alpha Team Member ✭✭
    edited January 2017
    The incidence of highest forward gain generally does not coincide with the incidence of best receiving pattern with deep F/B and F/S.  So by changing element length dynamically with TX v RX, you can design in more gain on TX which is desirable and best pattern on RX which is desireable.  On RX gain is not most relevant since it is signal to noise that dominates, and the whole point of a beam on RX is to eliminate unwanted noise.  On RX you basically always have more gain in the signal chain than you can use.  So changing the shape of the antenna on TX v RX maximizes each goal within a single antenna.  This idea is no different than using a 4 square on transmit (max directional gain) but using a beverage (max directional signal to noise) on receive on say 160M.   

    73  W9OY
  • Rick - W5FCX
    Rick - W5FCX Member ✭✭
    edited January 2019
    Unfortunately, after much experimentation with using micro controllers and relays to switch resonant antenna sections as an alternative to varying the conductor lengths, the amount of RF present is too much for the microcontrollers to handle. The initial BatBeam prototype was a failure.
    It was a fun project and R&D. Heck, that’s the point of ham radio isn’t it?

Leave a Comment

Rich Text Editor. To edit a paragraph's style, hit tab to get to the paragraph menu. From there you will be able to pick one style. Nothing defaults to paragraph. An inline formatting menu will show up when you select text. Hit tab to get into that menu. Some elements, such as rich link embeds, images, loading indicators, and error messages may get inserted into the editor. You may navigate to these using the arrow keys inside of the editor and delete them with the delete or backspace key.