HFU HF Underground

Technical Topics => Equipment => Topic started by: myteaquinn on September 19, 2019, 2334 UTC

Title: These Satellite Antennas Were Inspired by Origami
Post by: myteaquinn on September 19, 2019, 2334 UTC
Interesting article. But how much paper do you need to make an antenna for the 43 meter band?

https://www.airspacemag.com/airspacemag/satellite-antennas-inspired-origami-180972978/
Title: Re: These Satellite Antennas Were Inspired by Origami
Post by: Ray Lalleu on September 24, 2019, 1345 UTC
Interesting article. But how much paper do you need to make an antenna for the 43 meter band?
Design an 'origami wire' antenna. Just an idea : a halfwave long approx. antenna, but in a loop design, with the end of the arms facing to each other, then find a way to mechanically increase or decrease the distance between the parts that make a tuning capacitor.
An idea for that remote tuning without any electrical wire : air tube to some balloon, and a hand bike pump (for no RFI).
   
Title: Re: These Satellite Antennas Were Inspired by Origami
Post by: ThaDood on September 24, 2019, 1732 UTC
Huh??? To me, it looks like an inspiration from a toilet paper roll. i duh-know, but when I think of origami, I think of papered animals.
Title: Re: These Satellite Antennas Were Inspired by Origami
Post by: Josh on September 24, 2019, 1853 UTC
I can't see these working for long in space or near space. Space is actually corrosive and eats away at everything in it, a thinly plated origami antenna, already fragile, might not last long compared to solid metal wire antennae such as the typical quadri or crossed dipoles setup. Also, when a grain of meteorite or a paint fleck from a sat/rocket, much less a nut or bolt or a tesla car, traveling at 180000mph, is going to plasma vaporise a hole into anything it runs into.
Title: Re: These Satellite Antennas Were Inspired by Origami
Post by: ThElectriCat on September 25, 2019, 0400 UTC
This looks as far as I can tell like a foldable version of an single element axial endfire helical antenna (just a helix if you are familiar with satellite communications.
Those are usually several wavelengths long and the greater part of a wavelength or so in all other dimensions.
Pros.
        Nice wide bandwidth
        Tight beam of circularly polarized radiation
        Easy to match to 50 ohms with a flattened helix end
        Invented by John Kraus after a professor of his said "It will never work" (one does not stumble upon things this satisfying often)
Cons
        Ruining ones life by a mad, all consuming obsession to construct an antenna the size of a building and then figuring out how to point it as to work DX