# Should ground be shared between MOSFET gate, draing and source?

I'd like make a voltage buffer with MOSFET STD12NF06L-1 IPAK - STMicroelectronics

Configuration of Gate and Drain is given below:
(Ignore disconnected Source. I will do it later.)

Yellow circle indicates SMA port, a pair of signal and GND. Red and black are Vcc and GND, respectively.

What I concern is, USRP and power supply may have different GND level. And USRP consists of FPGA and daughterboards with ADC, DAC and signal processor.
I am worried that either USRP or power supply gets damaged if I connect both GNDs to meet each other.

Therefore, my question is, should they have shared GND? If yes, how do two different equipments share the GND?

• What kind of power supply is it? – Justin Mar 11 '15 at 14:48
• It is GPC 3030DQ from GW Instek. If you meant V source or I source. I think it is V source... I am not sure since I don't have much knowledge about electronics. – Jeon Mar 11 '15 at 14:57