Hi,
I am working on a visible light communication project. I have to modulate my LED with an RF data signal. The LED is mounted on a PCB and has terminals that can supplied with the signal input. I have purchased SMA pigtail connector with female input type(shown below).
One side of the cable is SMA female jack which I will connect to the RF signal generator. The other side of pigtail cable has two ends that can be soldered to PCB with LED terminals. My question is which of these terminals is cathode and anode. I think the center pin is cathode and has to be connected to LED cathode. Please correct me if I am wrong.

-Thanks,
Rakesh.

 

If your pigtail is carrying RF, that is an AC signal and so doesn't have anode/cathode.
I think you will need to have some DC bias on the LED and then use the RF to increase and decrease that DC current.

 

Thank you. I have not posted the block diagram of my system here. But I will use the bias-tee and superpose my Rf signal on it. and then send it to the LED.
From what you've mentioned, Can I solder any of those ends of pigtail cable to cathode of LED?

 

The one which has the negative DC should go to the cathode but which that is depends on how you add in the DC to the RF.

 

One thread is enough for the same project, this thread will be locked.

Please discuss in the first thread as following --
Biasing RF signal using Tee-bias.
https://forum.allaboutcircuits.com/threads/biasing-rf-signal-using-tee-bias.134845/#post-1127317