Page
9
of
10
INSTRUCTION
MANUAL
Horn
Antenna
(AH
‐
826)
19121
El
Toro
Road
Lake
Forest,
CA
92676
●
(949)
459
‐
9600
●
fax
(949)
459
‐
9604
●
com
‐
power.com
REV102913
7.0
Theory
of
Operation
7.1
Overview
Broadband
antennas
allow
measurement
of
signals
over
a
wide
frequency
range.
Model
AH
‐
826
Horn
Antennas
are
broadband
antennas
that
operate
in
the
frequency
range
of
18
to
26.5
GHz.
Model
AH
‐
826
can
both
receive
and
Transmit
over
the
frequency
range
of
operation
and
is
used
for
susceptibility
and
emissions
testing
in
EMC
Laboratories.
Before
the
Horn
antennas
are
used
for
measurement
they
have
to
be
calibrated.
During
calibration
of
a
known
field
strength
(dBµV/m)
is
generated
around
the
antenna
at
each
frequency
at
predetermined
intervals
between
18
GHz
–
26.5
GHz.
The
difference
between
field
strength
(dBµV/m)
received
by
the
antenna
and
known
field
strength
generated
(dBµV/m)
is
the
antenna
factor
(dB/m)
for
that
frequency.
During
EMC
testing
the
antenna
factor
for
the
frequency
of
interest
is
added
back
to
reading
on
the
EMI
meter
or
spectrum
analyzer
to
calculate
the
field
strength
measured
by
the
antenna.
Field
strength
(dBµV/m)
=
Output
measured
(dBµV)
+
Antenna
Factor
(dB/m)
W
hen
using
the
AH
‐
826
antenna
for
transmitting
application,
please
refer
to
Table
8.1
to
determine
the
power
requirements
to
generate
the
desired
electro
‐
magnetic
field.
