There’s lots of different application notes and PDFs and other documents regarding PCB antennas. But maybe someone has already tried to make one and knows it works? I’m looking for some finished application. Like a pcad or orcad or eagle or some other file with a board already designed.
Thanks!
A simple antenna is easy enough, it’s usually just a 1/4 wavelength track. It’s the matching network that is difficult to design - what chip are you using and what is the output impedance?
Leon
I’m using a module. It’s Hope RF’s RFM12B. Its antenna output is matched to 50 ohm impedance. I would prefer something other than 1/4 wavelength track because it’s rather long. Something more square.
That module has a 50 ohm output, presumably, which limits you to a 50 ohm antenna unless you use a matching network. The only simple 50 ohm PCB antenna is the 1/4 wave with a ground plane.
Leon
Aren’t there any antenna designs with a matching network to 50 Ohm already in place?
Also, correct me if I’m wrong, but isn’t this matching network something as simple as several capacitors and inductances?
Antenna’s are a complex/mystical art. You can try this:
beowulfenator:
Aren’t there any antenna designs with a matching network to 50 Ohm already in place?Also, correct me if I’m wrong, but isn’t this matching network something as simple as several capacitors and inductances?
Have you tried designing one and the PCB for it? It isn’t easy!
Leon
Isn't that why I was looking for a finished design in the first place? :Dleon_heller:
Have you tried designing one and the PCB for it? It isn’t easy!Leon
You’d be surprised what a finished design means. I was real interested in trying the TI low power chips. The reference antenna design isn’t just how long a trace you put on the board, you have to copy the layout exactly and you also have to allow for PCB thickness and copper thickness.
I know there are people here that have antenna simulators and stuff, but it looks like, if you really don’t want to spend the long amount of time studying all about antenna theory, your best bet is to simply start from one of the basic designs offered and experiment.
Copper thickness has a very small effect, I’ve found, and can be neglected.
Leon
That’s good to know, thanks.
Every once in a while I get the idea to do a transceiver with antenna and supporting passives on PCB and I study some more, then give up again.
Transceiver modules are pretty cheap now, and they are tough to beat, so I’d really rather not experiment too much with my own designs. I’ve got some of the MRF24 PICTAIL modules here and I’m trying to get an RF stack going here. I also have some RFM12B’s which I just ordered that look like a nice cheap module that I can adapt a network stack to.