On 2 mayo, 16:17, Cecil Moore wrote:
On May 2, 8:18*am, Wimpie wrote:

I would recommend you to measure something yourselves, ...

Please take a look at the numerous measurements performed by Walter
Maxwell.

Let's take a simple example of the single-port s-parameter results.
There exists a black box with one exposed port. The impedance is
measured to be 50+j0 and s11 is assumed to be zero when driven by a 50
ohm source. There could be a 50 ohm dummy load in the box but there is
not.

Actually, inside the black box is a 1/4WL Z0=100 ohm transmission line
routed to a 200 ohm resistor. s11 is certainly not zero and is
measured, using the 2-port procedure, to be 0.3333.

Which s11 is correct, 0.0000 or 0.3333?
--
73, Cecil, w5dxp.com
"Halitosis is better than no breath at all.", Don, KE6AJH/SK

Hello Cecil,

Assuming that your black box is a 100 Ohms quarter-wave line with 200
Ohms termination (all inside the black box), S11 (50 Ohms based) = 0,
as the input impedance of your black box is 50 ohms. If you like, you
may see your room temperature black box as a source with about –174dBm/
Hz output and an output impedance of 50 Ohms.

Wim