what will be the real output? RF model or low frequency mode

[liletian]

Hi guys
suppose the input signal is Vin, for a port of 50 ohms matches with a resistor 50 ohms, what will be the voltage on the resistor, Vin or Vin/2? I realized if you use Vsin component and port, they will give different voltage.
Another similiar question is if a port is open, what will be voltage , Vin or 2*Vin. It seems for RF we have to use wave format which is different from low frequency counterpart.
can anyoine explain on this? I really appreciate it.
Thanks,
B

 

[biff44]

Re: what will be the real output? RF model or low frequency

Yes, both!

It just depends on where the voltage is specified.

If specified at the Port, Vin is across the load.

If Your source is a "voltage source", then Vin is across the load

If your source is some ficticious mathematical entity, where there is a voltage source Vs, and a sepArate resistor meant to represent the "source impedance", then it develops Vs/2 across the load.

If it is a Microwave signal generatotr with an output power specified, that is the power coming out of the generator into a 50 ohm load.

Rich