http://www.ivorcatt.com/1_4.htm 
Partial reflection in a
transmission line. The book does not mention that considerations of
conservation of energy and also of continuity of voltage (difference) at the
transition shown in the middle of Figure 11 lead to the formula just below
Figure 11. It is obvious that the voltage at each side of the transition must
be the same. Also, electric current must not be created or destroyed. These requirements,
coupled with Ohm’s Law, lead to the formula. Thus, the statement in the book “It
is found experimentally that ….” is unnecessarily glib. However, the
assertion that the formula for reflection is not included in Maxwell’s
Equations is important. I am sure that it is generally thought that all this
kind of thing is included in Maxwell’s Equations. See http://www.ivorcatt.com/2804.htm I
Catt 23mar03 
