QFH
Introduction
Matching
Simulations
Dimensions
Groundplane
Related:
Simple helicoidal
When ON7EQ asked me if the QFH calculator on my site was reliable for higher frequencies, I just received a professionally designed GPS antenna from a Vaisala beacon. I determined the diam/height ratio to be 0.55 - probably quite directional vertically. Putting the data in the calculator gave exactly the dimensions of this antenna. (GPS - L1 - transmits on 1575 MHz).
So, at least up to 1600 MHz, things are very precise!
The antenna is just 55 mm long and 30 mm diameter.
(c) John Coppens ON6JC/LW3HAZ |