This is a 4G MIMO antenna for Band 28 (Australia 763 MHz). It was inspired by Damon Chandlers design here. I used the V5DKJ calculator. I have included blender design files in case someone wants to design for a different band based on this one.
This antenna being MIMO combines two Yagi antennas into one pole mount system. I used a 16mm (2 meter) curtain rod (available ~$5.99 in Australia at Bunnings), and some cheap ~2mm metal coat hangers. Total cost was around $10 AUD plus cabling, connectors and 3D filament.
I tested it with a Huawei E8372 dongle I got cheap on ebay. It is working well though I have not properly mounted it up high and tested it further. Initial rough estimate is about 10-12 db more compared to using just the dongle. My workshop is in a poor signal spot and trees block line of sight. It would likely do much better on a roof top with clear line of sight. My initial download speed tests indicate about a 3x increase but this is with poor line of sight (many trees).
If anyone wants a full parts list including connectors, cable, dongle, router, ethernet POE injector that I used to connect as gateway on my network then just ask. I'll add more detail.
Printed in Black 3DFillies PLA+, 0.2mm layers. Seems to be strong enough. I added some pole mount brackets but I have not fully tested these yet. I printed one and have it partly mounted. Needs further verification and I don't think I'll get to that very soon. The element brackets work nicely and that was my main goal here.
To build print 12 of the director (Yagi763MimoDir.stl) brackets and 1 of the radiator (Yagi763MimoRad.stl) bracket. Beam was cut to 1430mm. The remainder used as possible post for mounting to roof or whatever.
I've included the pdf files of Yagi calculator output for reference. Also I created a small spreadsheet to help calculate how far to push wires into each holder. I used super glue to lock them. The actual element brackets were tight enough (with a bit of filing) on the beam that so far I have just push fit them. There is small holes for inserting lock screws. I just wrapped the balun connections with teflon pipe tape for now. For real outdoor weather I'd suggest encasing in silicon goop with small bins. I didn't get around to designing those yet.
I think pretty much whatever you have will work.