
309Scattering Parameters
While a and b represent transmission and reection of power or voltage at
the input and output of the 2-ports, the s-parameter coefcients dened by
Equation 8.7 can be modied to
S
b
a
V
V
a
a
11
1
1
0
1
1
0
2
2
= =
=
=
reflected-at-port
towards-port
(8.92a)
s
11
= input reection coefcient with the output port terminated by a
matched load
S
b
a
V
V
a
a
22
2
2
0
2
2
0
1
1
= =
=
=
reflected-at-port
towards-port
(8.92b)
s
22
= output reection coefcient with the input port terminated by a
matched load
S
b
a
V
V
a
a
21
2
1
0
1
0
2
2
= =
=
=
outof-port2
towards-port
(8.92c)
s
21
= forward transmission (insertion) gain with the output port terminated
by a matched load ...