Best practices for WiFi antenna performance?

[dremuesp]

Using real Espresiff-branded ESP32-C3 dev kit, Arduino IDE. It's actually ESP-Now vs real WiFi, not that such should matter. (BTW, Espressif, ESP-Now is absolutely amazing for home automation, allows me to have my devices talking to each other doing their thing without tying up the WiFi AP's and DHCP scope etc etc. Thanks!)

That said, I'm finding that every now and again the outlying devices don't talk to or don't hear the one in the center (star topology.) I could re-do the thing as a mesh, I know, but they're interfacing with other powerline devices that wouldn't understand mesh and it would be messy. I do have some redundancy in the communication, it tries to verify that packets are receives and resends if not, etc, but that (1) means more traffic and (2) feels like I'm patching over an underlying problem rather than fixing it.

So, the question is, what's the best way to orient the board for optimum performance? Antenna up, down, sideways? (And yeah, I've read the coupla threads about square elbow antennas, not going there =))

Any other thoughts about improving wireless connectivity appreciated. Some of the end devices are using Wemos D1 mini clones, and those are vastly improved by using external antennas (I didn't mind scraping up a cheap chip to try it.) I don't know if that's worthwhile here and kinda hate to scrape up a good chip to find out

-- A

[czorgormez]

the best practice is to simulate & design your own antenna + matching network including your plastic box etc.

we do this way.

1- design or choose a suitable antenna for the selected frequency
2- create a dummy board with all metallic components + plastic box
3- connect that antenna to VNA and get S1P parameters file
4- use a matching tool or better professional software like opttenni lab
5- use exact values from that software for matching network parts. i mean if that software tells you
Murata 0603 xsr series etc. use that exact component.
6- add that matching network and test your board with VNA again.

I know it sounds complicated and yet is it complicated, but there is no simple shortcuts in rf world.