That would be 25 Watts minus 53 dB.
25 watts is 44 dBm
44 - 53 = -9 dBm? ?Or about? 1/10th milliwatt
Now you know why they like to keep the loops REAL close for inductive charging.
Kent WA5VJB
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On Thursday, June 30, 2022, 07:47:39 AM CDT, Marv <m207365@...> wrote:
I am trying to use my NanoVNA-H to see how much near-field coupling I have between two antennas in my backyard that are about 10 feet apart. I have one antenna connected to the S11 port and the other to the S21 port. I have S11 set to SWR and S21 set to LOGMAG. LOGMAG is -53dB at the point in the graph that both lines cross. I assume that is the amount of power being induced in the antenna connected to S21 by the antenna connected to S11.
Since the NanoVNA is only putting out a small amount of RF power, how would I relate that to for example transmitting 25 watts on one of these antennas and determining how much power is being induced in the other antenna?
