I am trying to desing a Helical antenna for the 433MHz ISM band.
I want to make the antenna as small as possible, but want a performance close to that of a 1/4 wave.
Design techniques for the helical antenna is what I am looking for.
I am trying to desing a Helical antenna for the 433MHz ISM band.
I want to make the antenna as small as possible, but want a performance close to that of a 1/4 wave.
Design techniques for the helical antenna is what I am looking for.
I think I might have mistaken what is being asked for. It sounds like you guys are talking about a helical wound 1/4 vertical antenna, where I was referencing helical wound BEAM antennas which have very high gain relative to a 1/4 antennas.
I think I might have mistaken what is being asked for. It sounds like you guys are talking about a helical wound 1/4 vertical antenna, where I was referencing helical wound BEAM antennas which have very high gain relative to a 1/4 antennas.
Yes, I think you were talking about completely the wrong type of aerial - but radio ham sites should have info on making what he wants, or at least the books should (ARRL or RSGB handbooks).
Thanks guys for the suggestions. I looked at the site suggested by Leftyretro and found that it has the equations to design the antenna.
From what I understand that a helical antenna can be used in normal mode(as a DIPOLE) by designing its diameter much smaller than its wavelength. I want to use the antenna for a telemetry based sensing project and space contraint is a big issue.
So, what do you REALLY want?
An antenna the size of a 1/4 wave, or one with large gain? It is not clear from your posts.
If you want a large gain, you need something bigger than a 1/4 wave.
An axial mode helix or a yagi with significant gain, will be (much) bigger than a 1/4 wave.