Greetings!
I want to know if anybody has made a successful 433mhz trace antenna. I’ve seen a post in august '19 but it’s closed now.
I don’t have any big testing equipments to do tests after tests, so something confirmed working would save a lot of time and money, maybe a kicad file?
Anyways, I would appreciate the help!
Thanks,
Fedack
If you need a successful 433 trace antenna, just lay down a straight trace 173mm long with a proper ground plane at the feed point and clear of any copper in the antenna plane.
It will be a reasonably well performing antenna, requiring only slight tuning.
However, if you need a compact antenna able to work efficiently in a tight space, that’s completely different story. Without proper tools (most important, VNA) you’ll not be able to ensure acecptable performance from such design. You won’t find an “off the shelf” layout that will give you 100% success.
My experience says, get a standard helical wire antenna designed for 433, and implement it in your design. Add some matching filters at the antenna feed point so you can easily match it later on. And hey, working VNA can be bought for less than $100 nowadays 
There is some good info and validation data on antennae design from TI here.
As @fred4u suggests, their recommended design is for a helical wire antenna or a ceramic chip antenna (less performant) at the 433MHz range.
By straight trace, do you mean perfectly straight or can I curve it around the board or soemthing like that? Would a spiral design work?
Unfortunately, by straight I mean literally straight, perpendicular to the ground plane. In most real life applications not possible due to space constraints.
Of course you can bend/spiral/etc whatever but most cases you will not get satisfactory results without a VNA.
Simplest designs to give you reasonable space and performance are the types mentioned previously. PCB antenna requires very careful design. Keep in mind that for 433, the antenna will be either bulky or poorly performing. For 868, I use wire helical antennas which perform much better than anything PCB of their size.
The reason I want a pcb antenna is because elliptical antennas keep having issues for me.
I bought a very nice board with a pcb antenna and I wanted to be able to do the same.
I sadly don’t have a lot of space to work with.
It’s weird nobody release a design yet. I don’t need it to perform super well, it just need to span a house or a room.
Ah well. It was worth a shot.
433 is a rather low frequency for a printed antenna as the wavelength is relatively long. I’d suggest a wire coil type.
22x50mm https://sci-hub.se/10.1109/AEMC.2015.7509138
If you want to use your existing ground plane, you will probably still need something like a NanoVNA to tune the antenna.
Thank you! It seems to be exactly what I need. I’ve never used a vna but I’ll look into it.
Don’t get your hopes up.
That’s not the type of design which will give you good performance without measurement instruments and lots of tuning/tweaking.
It probably works fine in a certain arrangement but it’s not a straightforward copy/paste design.
Been there, done that.
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