Cecil:

[snip]
From the IEEE Dictionary: "directional coupler - a two port circulator"

Heh, heh, just kidding. :-)
--
73, Cecil http://www.qsl.net/w5dxp
[snip]

:-)

Heh, heh... Actually the closest thing to a "two port circulator" is an
"ideal
transformer" it has the same scattering matrix as a two port circulator.

BTW... here's an interesting rhetorical question that is often posed
in texts on the scattering matrix.

How many different kinds of three port circulators are there?

--
Peter K1PO
Indialantic By-the-Sea, FL.