grit_fire
Member level 5
Hello all,
I have been thinking about this for a long time and am quite confused now. Need some help or brainstorming...
I was simulating two square loop coils (antennas) in Agilent ADS 2011 layout editor using Momentum. ADS gives me S-parameters, then I convert them to Z parameters. Then I can get my mutual inductance (M) between these two antennas by M=Z_12/(jW) or Z_21/(jw).
The confusing part is: why is my M a complex number? The imagnarity part is about 1e4 times smaller than the real part. But why is it even there? Even I am not using a substrate and the coils are in air, i.e. the relative permittivity is a real number, hence no substrate loss, no loss in the air. The material for my metal trace is perfect conductor (conductivity=5.8e7 siemens/m, hence the resistivity is almost zero). There should be no loss at all to cause a complex M, right?
Please give me some idea.. thanks!
I have been thinking about this for a long time and am quite confused now. Need some help or brainstorming...
I was simulating two square loop coils (antennas) in Agilent ADS 2011 layout editor using Momentum. ADS gives me S-parameters, then I convert them to Z parameters. Then I can get my mutual inductance (M) between these two antennas by M=Z_12/(jW) or Z_21/(jw).
The confusing part is: why is my M a complex number? The imagnarity part is about 1e4 times smaller than the real part. But why is it even there? Even I am not using a substrate and the coils are in air, i.e. the relative permittivity is a real number, hence no substrate loss, no loss in the air. The material for my metal trace is perfect conductor (conductivity=5.8e7 siemens/m, hence the resistivity is almost zero). There should be no loss at all to cause a complex M, right?
Please give me some idea.. thanks!