Reciprocity of matching circuits; are there any cases having no reciprocity?
I'm curious about reciprocity conditions of matching circuits.
For example, if we design a L matching circuit, it is matched at the source side as well as the load side although we designed the matching circuit focusing on the source side.
It is matched at the load automatically.
However, there must be exceptions, which the matching at the load side is not applicable automatically.
Can you explain the conditions?
Thanks
This is well outside my core expertise but I think you may
find examples in some of the less classical matching networks
like impedance-transforming ones used for Class E PAs and
so on in low voltage CMOS; the load is all that matters and
the driver port has two states only one of which could be
matched at all (the low-Z one).
But maybe this is the converse of what you're asking.
No not automatically.
The circuit's reactive values are each proportioned to match both impedances correctly only at one specific frequency.
Its not automatic, all three values must be chosen very specificity to work well.
In matching something like a radio transmitter to an antenna, usually two out of the three components are made variable, but the third component must be reasonably close to optimum to begin with.
If that is not the case, a "sort" of match can be found at resonance, but the circuit Q could be undesirably high or low leading to excessive losses and very inefficient operation.