I have a doubt about how to connect the following device (a RF power meter, AD8318) to the external circuitry. Let's consider the device:
There is the input RF coaxial cable, the power supply terminals (VCC and GND) and the output port. Regarding this last one, you may see that there are two terminals: the square terminal (which is GND) and the circular terminal (which is the signal output pin).
I have built the following stage of this circuit and I have connected its input pins between the circular terminal and GND of power supply terminals.
So my question is: is the GND of power supply the same GND of output port? Obviously they are short - circuited (so a multimeter will see a short circuit), so at low frequencies I would use them indifferently. But since this device works quite high input frequencies (1 - 8000 MHz), I was asking if there may be some problems, since at those frequencies also a little short circuit behaves like a transmission line.
So, can I avoid to use the square output terminal and take the output signal between GND of power supply terminals and the circular output terminal?