Com-Power AHA-118 - Manual

Active Horn Antenna
Features
Application
This antenna is suitable for accurately receiving low
amplitude radiated emission signals. It is used during
EMC testing for various standards such as FCC part
15, CISPR, and FAA for EMC emissions.
For obtaining valid data during the test, it is impera-
tive to maintain signal level above the noise floor.
In a typical setup, a receiving antenna is connected
to a preamplifier that is located next the spectrum
analyzer. The output of the preamplifier is then fed to
the spectrum analyzer. In this arrangement, since the
location of the preamplifier is far from the antenna,
the interconnecting cable is long. A combination of
factors such as a long cable, increasing cable loss
(especially for frequencies above 1 GHz), and high
antenna factors reduce the signal level to below the
noise floor of the preamplifier; and that produces
invalid readings. Boosting the signal at the antenna,
prior to its attenuation by long cables keeps it from
falling below the noise floor.
Each antenna is individually calibrated. The correction
factors and certificate of calibration is shipped with
the antenna. The data also includes separate antenna
factors and amplifier gain.
AHA-118
Description
The model AHA-118 Active Horn Antenna is basically
the AH-118 Horn Antenna with an integrated preampli-
fier. The preamplifier has a nominal gain of 20 dB for
the entire frequency range. The preamplifier improves
the effective system noise performance for emissions
testing as explained below. The antenna AH-118 is lin-
early polarized and has a frequency range of 1-18 GHz.
The output of the antenna is connected to the preampli-
fier by a short low loss cable, which can be removed.
This arrangement makes it possible to (1) insert a filter
before the amplifier and (2) use the antenna alone for
transmission. The filter insertion capability is impor-
tant and is required in presence of a high-level signal
(such as fundamental frequency), which possibly could
saturate the amplifier if the filter is not used. The trans-
mitted signal flow is in opposite direction and uses a
higher power level. Both conditions could damage the
preamplifier if not removed.
This antenna is constructed using lightweight aluminum
with a corrosion resistant conductive coating. The
rear mounting plate of the AHA-118 has 1/4 inch x 20
threads. These threads allow the antenna to be mounted
on a model AT-100 antenna tripod or any tripod with
similar mounting arrangement. The antenna is powered
by an supplied external DC wall mount adapter.
Com-Power Corporation (714) 528-8800 www. com-power.com [email protected]
Frequency Range – 1 to 18 GHz
Increased Sensitivity with a Built in Preamp
Two-year Warranty
Individual Calibration