I have a simple questions about the S-parameters S12 and S21.
I have two antennas connected to the VNA. If the S12 and S21 are exactly the same. I want to know how the antennas react to each other. I dont understand what it means. There's a picture attached. I don't understand waht happens with s12 and s21 at 4.4 GHz.
I have a simple questions about the S-parameters S12 and S21.
I have two antennas connected to the VNA. If the S12 and S21 are exactly the same. I want to know how the antennas react to each other. I dont understand what it means. There's a picture attached. I don't understand waht happens with s12 and s21 at 4.4 GHz.
Basically the power transfered from antenna A to antenna B is the same as from antenna B to antenna A.
That will almost always be the case for antenna, although it will not necessarily be so if there are non-linear devices like ferrites and you use enough power to saturate them.
Devices such as amplifiers will not have S12 and S21 the same.