
24-1
e notion of “phase” is usually associated with periodic or repeating signals. With these signals, the
waveshape perfectly repeats itself every time the period of repetition elapses. For periodic signals one
ca
n
th
ink
of th
e
ph
ase
at a gi
ven
ti
me
as th
e
fr
actional
po
rtion
of th
e
pe
riod
th
at
ha
s
be
en
co
mpleted
.
i
s
is co
mmonly
ex
pressed
in de
grees
or ra
dians,
wi
th
fu
ll
cy
cle
co
mpletion
co
rresponding
to 36
0°
or 2π ra
dians
. u
s,
wh
en
th
e
cy
cle
is ju
st
be
ginning,
th
e
ph
ase
is ze
ro
. Wh
en
th
e
cy
cle
is ha
lf
co
m-
pleted,
th
e
ph
ase
is ha
lf
of 36
0°,
or 18
0°
(s
ee
Fi
gure
24.1). It is im
portant
to no
te
th
at
if ph
ase
is de
ned
as th
e
po
rtion
of a cy
cle ...