Comment Re:Didn't say to get rid of circuit boards (Score 1) 349
I think we don't know yet what the real coupling mechanism is, but I believe that the author meant "capacitive induction", which is ambiguous but not incorrect.
"if capacitance and and inductance have opposite signs then would a capacitive inductance coupling be manifestly real (1/j *j =1)?"
Magnetic or inductive coupling hasn't necessarily a 90 degrees phase deviation, actually it is often rather "in phase" (real). The same is true for capacitive coupling (for instance, if you take a ceramic capacitor, hold it in the air, and apply a constant voltage referenced to earth to one lead, you can immediatelly sense that voltage on the other lead, as long as you don't take charge out from this second lead).
Furthermore, in common circuit design, when you want to couple an AC signal and block the DC component, signal is transferred almost without attenuation / phase change as long as this golden rule is respected: "the impedance of the capacitor at the desired signal frequency must be much lower than the impadances in series with it". And yes, you get voltage and current passing through the capacitor, both in phase, and power transferr is acomplished.
"if capacitance and and inductance have opposite signs then would a capacitive inductance coupling be manifestly real (1/j *j =1)?"
Magnetic or inductive coupling hasn't necessarily a 90 degrees phase deviation, actually it is often rather "in phase" (real). The same is true for capacitive coupling (for instance, if you take a ceramic capacitor, hold it in the air, and apply a constant voltage referenced to earth to one lead, you can immediatelly sense that voltage on the other lead, as long as you don't take charge out from this second lead).
Furthermore, in common circuit design, when you want to couple an AC signal and block the DC component, signal is transferred almost without attenuation / phase change as long as this golden rule is respected: "the impedance of the capacitor at the desired signal frequency must be much lower than the impadances in series with it". And yes, you get voltage and current passing through the capacitor, both in phase, and power transferr is acomplished.
