Comb
Generators
model
CGO
‐
520
Page
8
of
11
(949)
459
‐
9600
www.com
‐
power.com
Rev.
0216
Theory
The
Comb
Generator
uses
an
impulse
to
generate
its
step
frequency
output.
It
uses
a
stable
power
supply
and
signal
shaping
circuit
to
obtain
relatively
stable
signal
output
with
frequency
components
extending
beyond
1
GHz.
The
Comb
Generator
operates
on
battery
power.
The
battery
output
is
controlled
by
a
voltage
the
regulator
circuit
to
provide
stable
power
output
to
the
signal
generating
circuit.
The
signal
generating
circuit
consists
of
a
clock
generator,
impulse
generator,
wave
shaping
circuit
and
output
matching.
The
signal
frequency
is
generated
by
a
crystal
oscillator.
An
impulse
in
time
domain
corresponds
to
a
flat
output
across
the
entire
frequency
spectrum
in
frequency
domain.
An
ideal
impulse,
by
definition
is
an
infinite
magnitude
pulse
with
zero
rise
and
fall
time
with
zero
duration.
Such
a
pulse
is
not
practical;
however,
the
Model
CGO
‐
520
Comb
Generators
use
this
principle
to
get
an
output
across
a
wide
band.
The
highly
stable
frequency
output
from
the
oscillator
is
used
to
generate
an
impulse
with
very
short
duration
and
sharp
rise
and
fall
times.
The
shaping
circuit
was
designed
for
improved
stability,
extended
frequency
response,
and
output
impedance
matching
to
50
ohms.
The
radiated
reference
signal
is
transmitted
by
the
antennas
affixed
on
top
of
the
unit.
An
electrically
short
monopole
antenna
is
an
antenna
that
is
short
compared
to
the
wavelength
of
the
frequency
it
radiates.
Such
an
antenna
generates
a
radiated
field
proportional
to
its
length.
The
radiated
field,
therefore,
compensates
for
decreasing
signal
up
to
a
frequency,
where
the
antenna
cannot
be
called
electrically
short.
This
theory
describes
the
general
behavior
of
the
field,
but
each
Comb
Generator
may
behave
slightly
different
than
the
other
due
to
circuit
variation.
Since
the
Comb
Generators
were
designed
to
provide
a
reference
reading
at
a
given
frequency,
this
limitation
is
not
a
problem.
