On Thu, Oct 29, 2020 at 11:35 PM, John Gord wrote:
I think you are correct: Presumably the designer did not want to go to
the expense and effort to do a good "L" match, and found that the combination
of resistive input matching and no output matching gave acceptable results.
Meanwhile, I had a look at my board and I found the "0 ohm" resistor might be the only component I can see on the output part - I didn't expect such a resistor could exist.
That would mean I can replace it to set up a network using the pads available on the PCB.
It is also possible that the intent was to demonstrate that for most
passive circuits, S21=S12, but S11 does not necessarily equal S22. You should
be able to see this by reversing the connections: Forward and reverse
transmission should look about the same, but the input impedance will look
quite different.
Nice prompt, thanks! I was not thinking of the ceramic filter as a symmetric element.
I'm starting to have fun. :-)
A.
