I tried to draw a PCB antenna with top metal layer and put a smd pad on it for pin connection. DRC always complains about the clearance… which is understanable, the smd pad is touching some metal layer…
can anyone tell me what’s the right way to do this?
thanks.
I’d be tempted to make a part for it. I assume you mean a microstrip antenna with precise dimensions. The advantage of making a part is you can reuse it with out having to go through the process of precisely laying it out each time.
i am trying to make it a part. Otherwise, I won’t be putting a pad to the antenna.
You may just try naming the pour (antenna plane) the same a pad. I’ve never tried it…The pad and plane may have to have the same name in the component file to be connected and not have the clearance issue.
James L
daredge:
i am trying to make it a part. Otherwise, I won’t be putting a pad to the antenna.
Greetings (No name supplied),
Can you post the schematic and library files? I think EAGLE will alway report a DRC error if a pad keepout is too close to another element.
Design a proper library part (as someone else suggested) and use it everytime. If you are trying to create a library part I don’t think you can used a pad or via (unless it is has the correct PIN properties). Why would a PCB foil antenna need a via or hole?
Comments Welcome!
daredge:
I uploaded my test case [Here[/quote]daredge,
Thanks for posting your work, I don’t have a solution for you yet. The largest SMT pad that I could make is approx. 500mils - your antenna is 100 x 1350 mils. So making a large SMT pad in the library editor and then placing it on your board won’t work.
Any combination of SMT pad and top metal trace or top metal rectangle that I tried would not accept a connecting pad (and therefore lacked air-wires in the board editor). Placing an SMT pad next to (i.e. connecting) to a top metal trace causes a DRC clearance error (as you noted).
A DRC clearance error will not stop your PCB fro being fabbed (many DRC errors can be ignored), provided you know in advance of the DRC error and delete it as you clean up after running the DRC.
Perhaps the folks at CADSoft can help? There’s an EAGLE user’s newsfeed forum.
If you find an answer please share it here!
Comments Welcome!](Box)
Here’s what I did:
I created a part that is just a single through-hole pad, and made this my antenna in the schematic. I made a trace from my pin to the antenna pad, then drew a polygon around it in my desired shape. I named the polygon the same as the trace, and it filled just fine, connected to the pad, and there were no DRC errors. Keep in mind that the trace needs to correspond to a network in the schematic, and they all have to have the same name. Make absolutely sure the connections in the schematic are orrect.
mtwieg:
I created a part that is just a single through-hole pad, and made this my antenna in the schematic.
Mike,
If that works for you fine! However, I think the antenna requires no through holes and to be of a specified area to act as a radiator.
Any distortion to the impedance of the traces will cause reflections, bad SWR, and lower radiated power (or lower receiver sensitivity).
mtwieg:
I made a trace from my pin to the antenna pad, then drew a polygon around it in my desired shape.
The advantage of a creating a library part is that the polygon doesn’t have to be drawn for each instance. If this component is used only once in a while then drawing it fresh each time is not much of problem.
Comments Welcome!
I was contemplating something similar today, and found this discussion.
I’m interested has anyone successfully completed an 2.4 GHz antenna part that could be included in a library and simply dropped into a design?
asteriskPDX:
… has anyone successfully completed an antenna part that could be included in a library and simply dropped into a design?
I asked a similar question at the Eagle Technical forum, and the answer was “no”. You can make a part and ignore the DRC errors, or you can make a polygon and give it the same name as the net.
Sorry, but that’s the way it is.
Jake