Not sure if its in order to share this on this thread but this is about antennas.
I was reading this article on “Antenna Basic Concepts” and came across the “5/8 over 5/8 over 1/2” collinear antenna design. I wonder if anyone has tried this for LoRa frequencies.
I did try out the design for an 868MHz collinear antenna, using core from an RG-6 coaxial cable. The lowest section was roughly 172mm, while the upper sections were roughly 215mm each. I say roughly because I wasn’t taking very precise measurements. The loops in between sections had a 30mm diameter.
I tested this by replacing an existing quarter wavelength antenna with new contraption (not having a VSWR meter this seemed a reasonable first test.). Surprisingly, I notice roughly 11dbm improvement on signals received from a gateway I have installed between this antenna on a node and a quarter wavelength antenna on same node. This difference was maintained consistently with two similar nodes, one having this antenna and the other using a quarter wavelength antenna. I also notice same difference between this and other 868MHz antennas I have, all quarter wavelength.
I haven’t tested this for range but will do so in the coming days.
Has someone tried this design and can the person share the experience?