SMA connector question

[docmur]

Hey

I have a both a Bluetooth and WiFi module on my new project and I wanted to go with a SMA Antenna, in place of a chip or trace antenna.   When designing for chip and trace antennas I know you have to be careful to match lengths and on how you route them.  My question is how careful do you have to be when using SMA connectors in place of chip and trace antennas.   Can I just place the SMA connector at the edge of my board and run a trace back to modules?  Do I have to match for wave length?

[salbayeng]

Hi,
You need to match for impedance first, from memory 50ohms is around 100mil on a standard 1.6mm PCB.  A thinner board allows thinner traces!

And don't have any 90degree bends.

Another trick is to contrive to have tracks that are multiples of half-wavelengths I think that's around 2-1/2" for 2.4GHz , 1/2 wavelength lines just replicate the impedance of one end to the other, so it's not critical if your track isn't exactly 50ohms ,(  i.e +/- 50%)

[docmur]

Thanks :-)

I actually just discovered an impedance matching router in Altium that I never knew existed.