I am seeking assistance regarding the connection of MIKROE-4503 to an SMA interface. I would like to know the correct way to connect the signal and GND in this scenario. They have used a multimeter to test the two pins and found them to be short-circuited (impedance < 1 ohm). Could you please provide guidance on where exactly the signal and GND should be connected in this case?
product link: MIKROE-4503 MikroElektronika | RF and Wireless | DigiKey
Thank you for your help.
Hello and Thank you for contacting DigiKey’s technical forum.
We are looking into this and will get back to you as soon as we can.
The schematic for the board is available from the manufacturer’s website, and makes clear that a short circuit at DC is to be expected.
As a general rule, the shield of a coaxial cable carrying RF signals will be the “grounded” one. The whole idea is to create an enclosed tunnel that protects a sensitive (or offensive) signal from interference (or interfering) with the rest of the world. It doesn’t make much sense to build a tunnel only to walk on the outside of it…