Lora 868MHz biquad antenna

This is part of my Long Range Weather Station project : https://hackaday.io/project/191652-long-range-weather-station

I wanted to increase range for my 868 MHz lora devices. I followed the link of this "biquad calculator" : https://www.changpuak.ch/electronics/bi_quad_antenna_designer.php

Biquad antenna is a kind of loop antenna with a simple design, easy to build and offers a good characteristic of directivity and gain for point to point communications. It consists of two radiating elements made of connected squares with the side length equal to ¼ mid-band wavelength.

I built this simple jig which can be used both for folding the 2mm coper wire, but also as a permament holder.

To even increase the range I should have added a metal ground plane to reflect the back lobe to the front side.

Without this ground plane my antenna acts more like an "omni" antenna. But who cares ? It works fine !

Print it in PET or PETG to resist to rain, UV and high temperatures...

I printed it with home made PET plastic bottle filament : https://hackaday.io/project/185196-pullstruder-from-plastic-bottle-to-pet-filament

Print Settings

Printer Brand:

Prusa

Printer:

i3 MK2S

Rafts:

No

Supports:

No

Resolution:

.3mm

Infill:

20

Filament: none PET green plastic bottle