I am delivering power to my device using a VNA with frequency ranging from 300kHz to 8GHz. I am trying to figure out the current that passes through my sample, or DUT. I can set the output power of the VVNA and measure the S11. Here is my approach.
Since the total voltage and current (the sum of the incident and reflected waves) at the DUT can be expressed as:
$V=\frac{V_0}{Z_0}(1+\Gamma)$
$I=\frac{V_0}{Z_0}(1-\Gamma)$
Taking the current formula, and use $P_0=I*V_0$, the total current can be expressed as
$I=\sqrt{P_0 (1-\Gamma)/Z_0}$, where $\Gamma=10^{(S11/20)}$.
Is the above formula correct?
Another method that I thought of is to first measure the DC resistance, $R$. Then, the current can be derived as:
$I=\sqrt{P_0(1-\Gamma^2)/R}$
Is any of these correct? Any help is much appreciated.
