COM-power corporation AH-8055 User manual

Page 1 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
INSTRUCTION MANUAL
for
HIGH GAIN
HORN ANTENNA
Model: AH-8055
800 MHz to 5 GHz
(useable up to 6.5 GHz)

Page 2 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
Table of Contents
1.0 Introduction ........................................................................................................... 4
2.0 Products Available from Com-Power ................................................................. 5
3.0 Product Information .............................................................................................. 6
3.1 Incoming Inspection....................................................................................................... 6
3.2 Package Inventory ......................................................................................................... 6
3.3 Product Connections ..................................................................................................... 7
Figure 1 – Product Connections ................................................................................................................ 7
3.4 Product Specifications ................................................................................................... 8
Figure 2 – Product Dimensions ................................................................................................................... 8
4.0 Measurement Correction Factors ....................................................................... 9
4.1 Antenna Factors............................................................................................................ 10
4.2 Preamplifier Gain Factors ............................................................................................ 11
4.3 Insertion Loss Factors..................................................................................................... 11
4.3.1 Insertion Loss Measurement ........................................................................................ 12
4.3.1.1 Insertion Loss Measurement Procedure ............................................................ 12
Figure 3 – Setup for Reference Measurements (R) ............................................................................... 12
Figure 4 – Setup for Insertion Loss Measurements (I) ............................................................................12
5.0 Antenna Configurations (Modes of Operation) ............................................... 13
Figure 5 – Antenna Configurations (Modes of Operation) ................................................................. 13
5.1 AH-8055 as a Transmitting Antenna ........................................................................... 14
Figure 6 – AH-8055 as a Transmitting Antenna ...................................................................................... 14
Figure 7 – Typical Equipment Arrangement for Transmitting Applications ...................................... 14
5.1.1 Field Strength Calculations.......................................................................................... 15
Figure 8 – Calculated Field Strength with 450W input power............................................................. 15
Figure 9 – Power requirements for various fields strengths/distances ............................................... 15
5.2 AH-8055 as a Receiving Antenna .............................................................................. 16
Figure 10 – AH-8055 as a Receiving Antenna ....................................................................................... 16
5.2.1 Field Strength Measurements and Example Calculations ..................................... 17
Figure 11 – Typical Equipment Arrangement for Receiving Applications........................................ 17
5.2.2 Avoiding Preamplifier Saturation................................................................................ 18
6.0 Calibration and Re-Calibration ......................................................................... 19
7.0 Warranty............................................................................................................... 20

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INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
8.0 Typical Performance Data ................................................................................. 21
Figure 12 – Typical Antenna Factors and Isotropic Gain Values ....................................................... 21
Figure 13 – Typical VSWR/Return Loss ..................................................................................................... 22
Figure 14 – Typical 3 dB Beamwidth........................................................................................................ 22

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INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
1.0 Introduction
This manual includes product specifications, safety precautions, warranty information,
guidelines and usage instructions for the AH-8055 for different applications.
Information contained in this manual is the property of Com-Power Corporation. It is
issued with the understanding that the material may not be reproduced or copied
without the express written permission of Com-Power.

Page 5 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
AntennasAntennaKits AbsorbingClamps Coupling/Decoupling
Networks(CDN)
CombGeneratorsCurrentProbes EmissionsTest
Systems
ConductedImmunity
TestSystems
ImpedanceStabilization
Networks(ISN)
LineImpedanceStabilization
Networks(LISN)
AntennaMasts Near‐Fiel
d

ProbeSets
PreamplifiersPowerAmplifiers
S
pectrumAnalyzers ProductSafetyTest
Equipment
TransientLimitersTurntables AntennaTripods TelecomTest
Systems
2.0 Products Available from Com-Power
www.com-power.com

Page 6 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
3.0 Product Information
3.1 Incoming Inspection
Please check the contents of the shipment against the package inventory in
section 3.2 to ensure that you have received all applicable items.
If shipping damage to the product or any of the accessories is suspected, or if the
package contents are not complete, contact Com-Power or your Com-Power
distributor.
3.2 Package Inventory
9AH-8055 High Gain Horn Antenna
9Calibration Certificate and Data

Page 7 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
3.3 Product Connections
Figure 1 – Product Connections
Antenna Port (input/output)
Antenna port is a precision, female N-type connector. When used as a receiving
antenna, this port is the antenna output port. Conversely, when used as a
transmitting antenna, it is the antenna input port.
Mounting Hole for Horizontal Polarization
This is a ¼” x 20 threads mounting hole for the horizontal antenna polarization.
Mounting Hole for Vertical Polarization
This is a ¼” x 20 threads mounting hole for the vertical antenna polarization.
1
2
3
1
3
2

Page 8 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
3.4 Product Specifications
Technical
Frequency Range 800 MHz to 5 GHz (useable up to 6.5 GHz)
Polarization Linear
Nominal Impedance 50Ω
Power Handling 450 Watts (continuous)
Antenna Factors 13.8 to 24.2 (average: 19.7)dB/m
Isotropic Gain 10.6 to 23.1 dBi
VSWR (antenna port) 1.17 to 2.88 (average 1.69):1
Return Loss (antenna port) 6.3 to 22 (average: 13) dB
RF Connector
Antenna Port Connector Precision N-type (female)
Mechanical
Dimensions (H)x(W)x(D) 17.2” x 18” x 27.2” (43.7 x 45.7 x 69.1 cm)
Weight 20.5 lbs (9.3 kg)
Figure 2 – Product Dimensions
(W)
18” (45.7 cm)
(H)
17.2” (43.7 cm)
(D)
27.2”
(69.1 cm)

Page 9 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
4.0 Measurement Correction Factors
Anyone familiar with EMI radiated emissions measurements understands that
‘uncorrected’ values measured on your spectrum analyzer or EMI receiver are essentially
meaningless without the appropriate ‘correction’ factors for the individual components
of your measurement system.
A typical radiated emissions measurement system can include any combination of the
following components, all of which have a quantifiable effect value on the measured
voltage; and therefore must be accounted for to accurately ‘correct’ your reading:
•Receiving antenna(s)
•Preamplifier(s)
•Coaxial measurement cable(s)
•Attenuation Pad(s)
•Connecting Adapter(s)
•Low-Pass, High-Pass or Notch Filter(s)
•DC Block(s)
•Other similar measurement components
We can separate the factors associated with the above components into three basic
categories:
1) Antenna (or transducer) Factors,
2) Gain Factors (for preamplifiers); and,
the cables, attenuators, adapters, filters, etc., can all be lumped into one general
category…
3) Insertion Loss Factors
These three categories of correction factors are discussed in the following sections.
Most of today’s spectrum analyzers and EMI receivers allow entry of these factors directly
into the instrument. You can then group the factors into factor sets, so that the
appropriate cables factors are used with the correct antennas, preamplifiers, etc. This
makes things very convenient, and allows the instrument to display/output test results as
the corrected values, with no further correction necessary. These newer instruments will
also allow you to enter the specification limits, so that PASS/FAIL can be determined
instantaneously.
Older instruments, however, do not have this capability, so manual correction, or
correction through data acquisition PC software (or other means) is needed.
Whatever the case may be, applying the CORRECT correction factors is obviously key to
achieving accurate results. A simple typo when entering factors into your instrument or
PC software will give you incorrect data until such time that you notice the mistake, or
until you recalibrate and enter the new factors. It is a good idea to check your entries.

Page 10 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
4.1 Antenna Factors
Antennas used for EMI tests for frequencies above 30 MHz are typically provided
with electric field antenna factors (AFE). These factors are almost always
provided in logarithmic units in dB per meter (dB/m) or (dBm-1), and their values
tend to vary with respect to frequency.
Antenna factor is defined as the “ratio of the electric field in the polarization
direction of the antenna to the voltage induced across the load connected to
the antenna and expressed in decibel form (20 log (E/Vo)).”
Put more simplistically, the antenna factor represents the difference (in dB)
between:
A) the voltage present across the output port of the antenna (measured on
an instrument with a 50Ωinput impedance), and;
B) the electric field strength (V/m) present at the mid-point of the antenna’s
elements, or in the case of a horn antenna, at the front plane of its
aperture (opening).
As any antenna is less than 100% efficient (without amplification), the voltage
present across the antenna output port will always be less than that present in the
measured field, so the antenna factor can be considered a loss, and is added to
the measured value to obtain the field strength:
Antenna Factor (dB/m)
+
Measured Value (dBμV)
Field Strength (dBμV/m) =

Page 11 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
4.2 Preamplifier Gain Factors
Our second category of correction factors are gain factors for preamplifiers.
Preamplifiers are used to increase measurement sensitivity by increasing signal to
noise ratio. This is necessary when measuring low signal levels which would
otherwise be buried below the inherent noise floor of the measuring instrument,
typically a spectrum analyzer or EMI receiver. Ideally, input signals levels are
increased proportionate to the preamp’s gain, without significantly increasing the
overall system noise level.
Since the amplitude of the measured signal has been increased by the gain of
the preamplifier, the gain value must then be subtracted from the measured
value in order to obtain the ‘corrected’ value. Hence, our field strength formula
is modified as follows:
4.3 Insertion Loss Factors
As discussed previously, our third category of correction factors is insertion loss
factors. These factors can include the insertion loss values of coaxial cables,
band-pass or notch filters, attenuation pads, connecting adapters, etc. Basically,
it includes any measurement system component (cable, adapter, combiner,
divider or any other device) installed in-line with your measurement path having
inherent insertion loss over the frequency range of the measurements,
intentionally or unintentionally, beyond that which is considered to be negligible.
If the exact insertion loss factors (or values) are unknown for one or more
component(s) of your measurement system, refer to section 4.3.1.
Insertion loss factors (or values) must be added to the measured values in order to
obtain the ‘corrected’ values. So, we can update our field strength calculation
formula as follows:
Antenna Factor (dB/m)
+
Measured Value (dBμV)
Field Strength (dBμV/m) =
Preamp Gain Factor (dB)
-
Insertion Loss Factors (dB)
+
Antenna Factor (dB/m)
+
Measured Value (dBμV)
Field Strength (dBμV/m) =
Preamp Gain Factor (dB)
-

Page 12 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
4.3.1 Insertion Loss Measurement
Insertion Loss values for coaxial cables and most measurement system
components having a single coaxial input and output, such as
attenuators, filters, dc blocks, etc., can be easily determined through a
simple calibration process.
All that is typically needed is the following:
9(2) short coaxial cables and ‘barrel’ adapter to connect them together;
and,
either:
9a network analyzer or measuring instrument (spectrum analyzer or EMI
receiver) with tracking generator;
or:
9a measuring instrument (spectrum analyzer or EMI receiver); and,
9a stable signal source with the appropriate frequency capabilities, such as
a signal generator, function generator, or even a Com-Power Comb
Generator.
4.3.1.1 Insertion Loss Measurement Procedure
1) REFERENCE MEASUREMENTS (R) - With the equipment set up as
shown in Figure 3, measure and record the signal level (in dBμV)
at several frequencies over the frequency range to be
calibrated.
Figure 3 – Setup for Reference Measurements (R)
2) INSERTION LOSS MEASUREMENTS (I) – Without changing any
equipment settings, and with the equipment set up as shown in
Figure 4, measure and record the signal level (in dBμV) at the
same frequencies used in Step 1.
Figure 4 – Setup for Insertion Loss Measurements (I)
3) Calculate the insertion loss factor for each frequency using the
following formula:
Insertion Loss Factor =(R) minus (I)
Signal Source
Measuring
Instrument
coaxial cables
‘barrel’ adapter
Signal Source
Measuring
Instrument
coaxial cables
system component
to be calibrated
X

Page 13 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
5.0 Antenna Configurations (Modes of Operation)
The AH-8055 high gain horn antenna, while designed primarily for use as a transmitting
antenna, may also be used as a receiving antenna.
Figure 5a – Transmit Mode Figure 5d – Receive Mode
Figure 5 – Antenna Configurations (Modes of Operation)

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INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
5.1 AH-8055 as a Transmitting Antenna
Illustrated in Figure 6 is the AH-8055 High Gain Horn Antenna configured for use as
a transmitting antenna. Illustrated in Figure 7 is a typical system arrangement for
this antenna configuration, with the antenna port connected directly to the
output port of a power amplifier. In practice, a power amplifier may or may not
be used, depending on the desired magnitude of the generated field.
Figure 6 – AH-8055 as a Transmitting Antenna
In this configuration, the AH-8055 is used as a transmitting antenna. Some
examples of these applications are listed below:
oSite Validation tests, such as the reciprocal SVSWR procedure described in
CISPR 16-1-4
oRadiated RF Immunity (or susceptibility) testing, such as that described in
IEC 61000-4-3, MIL-STD 461x, DO-160, etc.
oAntenna Calibrations per ANSI C63.5, ARP 958, etc.
For applications such as those listed above, the isotropic gain factors have
importance, rather than the antenna factors, as described in section 5.1.1.
Figure 7 – Typical Equipment Arrangement for Transmitting Applications
RF SIGNAL
GENERATOR
RF POWER
AMPLIFIER

Page 15 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
5.1.1 Field Strength Calculations
The graph shown in Figure 8 shows the calculated maximum field strengths
(based on typical gain factors) able to be achieved using the AH-8055
High Gain Horn Antenna with 450 watts input power at both one and
three meter distances, as well as the formula used for the calculations.
Figure 8 – Calculated Field Strength with 450W input power
The graph shown in Figure 9 shows the calculated power requirements
(based on typical factors) for various field strength levels at various test
distances, as well as the formula used for the calculations.
Figure 9 – Power requirements for various fields strengths/distances
10
100
1,000
10,000
0.5 1.5 2.5 3.5 4.5 5.5 6.5
Frequency (GHz)
Field Strength (V/m)
Ant. Input (W) * 30 * [numeric] Gain
Test Distance (m)
Field Strength (V/m) =
1 meter
3 meters
0.01
0.1
1
10
100
1000
0.5 1.5 2.5 3.5 4.5 5.5 6.5
Frequency (GHz)
Forward Power (Watts)
150 V/m @ 1m
200 V/m @ 1m
3 V/m @ 3m
10 V/m @ 3m
Field Strength (V/m)
2
* Test Distance (m)
2
30 * [numeric] Isotropic Antenna Gain
Fwd. Power (Watts) =

Page 16 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
5.2 AH-8055 as a Receiving Antenna
Illustrated in Figure 10 is the AH-8055 High Gain Horn Antenna configured for use
as a receiving antenna. Illustrated in Figure 11 is a typical system arrangement for
this antenna configuration, with the antenna port connected to the input of a
preamplifier, and the preamplifier connected to the input of a spectrum analyzer.
In practice, a preamplifier may or may not be used, depending on the
magnitude of the signals(s) being measured.
Figure 10 – AH-8055 as a Receiving Antenna

Page 17 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
5.2.1 Field Strength Measurements and Example Calculations
As discussed in section 4, the measured values must be corrected for
antenna factor, preamplifier gain and any losses incurred along the
measurement path.
Figure 11 – Typical Equipment Arrangement for Receiving Applications
EXAMPLE:
Using measurement system shown in Figure 11, a signal at 2 GHz is
observed using the spectrum analyzer, and its [uncorrected] amplitude is
exactly 60 dBμV. The field strength limit at this frequency is assumed to be
500 μV/m (54 dBμV/m).
For the system shown above, there are four (4) correction factors needed:
1) The AH-8055 Antenna Factor
2) The Insertion Loss Factor for the cable connecting the AH-8055 to
the preamplifier (Cable #1)
3) The Insertion Loss Factor for the cable connecting the preamplifier
to the spectrum analyzer (Cable #2)
4) The gain of the RF preamplifier.
We’ll assume that the insertion loss of the Cables #1 & #2 at 2 GHz is 8 dB
and 2 dB, respectively. The preamplifier gain is 40 dB; and, by referring to
the typical antenna factor tables in Section 8, we see that the Antenna
Factor for the AH-8055 at 2 GHz is 20.82 dB/m (in practice, you will use your
actual calibrated factors rather than the typical factors). So our
calculation will be as follows:
Measured amplitude @ 2 GHz,
with a 3-meter separation distance = 60 dBμV
AH-8055 Antenna Factor @ 2 GHz = 20.82 dB/m
Insertion Loss of Cable #1 @ 2 GHz = 8 dB
Insertion Loss of Cable #2 @ 2 GHz = 2 dB
Preamplifier Gain @ 2 GHz = 40 dB
= 50.82 dBμV/m
FCC Part 15 Field Strength Limit @ 3 meters = 54 dBμV/m
Limit Δ(margin) = -3.18 dB
Antenna Factor (dB/m)
+
Measured Value (dBμV)
Field Strength (dBμV/m) =
Preamp Gain Factor (dB)
-
Insertion Loss Factors (dB)
+
RF
PREAMPLIFIER

Page 18 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
5.2.2 Avoiding Preamplifier Saturation
When testing in the presence of high amplitude signals, whether they are
generated by the device under test, or from external sources such as
radio towers, cellular repeaters or otherwise, it is always advisable to
check for overload of your preamplifier, in order to avoid inaccurate test
results.
The following procedure will usually be sufficient to detect an overload
condition of your preamplifier:
1) Tune your measuring instrument to the frequency of the offending
(or possibly offending) signal. Adjust the frequency span to be wide
enough to view the entire envelope of the waveform. Maximize the
emission level by rotating your turntable and scanning the antenna
height, as needed, so that the maximum level is shown on the
display. Note the height of the antenna for the maximum level.
2) Use the max-hold/view trace functions to store the outline of the
signal on the analyzer screen, or simply note the signal amplitude
level.
3) Disconnect the cable connecting the antenna to your preamplifier.
Connect an appropriately rated coaxial attenuator (at least 10 dB)
to the preamplifier input port, and connect the antenna cable to
the attenuator input. Reposition (if necessary) the antenna to the
height noted in Step 1.
4) Re-measure the amplitude of the signal, and compare it to the
amplitude determined in Step 1. The amplitude reduction should be
equal to the attenuator value. If the amplitude reduction of the
signal is not equal to the attenuator value, then it is likely that the
amplifier is saturated. If this is the case, refer to section 5.2.
In situations where there are high signal levels which are saturating the input to
the preamplifier an attenuation pad or RF filter is installed in order to avoid
preamplifier saturation.
Attenuation pad(s) are often used temporarily for saturation checks, as discussed
in section previously.
Attenuation pad(s) may also be used for tests performed in high ambient
conditions. Using attenuators for this purpose will sacrifice system sensitivity and
signal to noise to noise ratio performance, which is obviously not desirable.
Custom Low-Pass, High-Pass or Notch Filters are commonly used for tests
performed on intentional radiators. The filter attenuates a specific frequency
range to suppress the amplitude of the fundamental emission in order to avoid
saturation. Outside of the cutoff band, these filters usually have very low insertion
loss factors, so that the overall sensitivity and signal to noise ratio of the
measurement system is not compromised.
The insertion loss value of the attenuation pad and/or filter must be considered
when correcting your measured values (see section 4.3).

Page 19 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
6.0 Calibration and Re-Calibration
Your AH-8055 High Gain Horn Antenna has been individually calibrated and the data has
been provided.
Periodic re-calibration of your AH-8055 is recommended when it is used as a receiving
antenna. Calibration intervals is left to your discretion, but should be chosen based on
the frequency with which it is used, and/or as allowed for by your internal quality control
system (if applicable). Com-Power does offer NIST traceable calibration services
For transmitting applications, re-calibration of the antenna is not typically necessary, as
the field generated by the antenna is typically measured using a calibrated field probe.

Page 20 of 22
INSTRUCTION MANUAL
AH-8055 HIGH GAIN HORN ANTENNA

19121 El Toro Rd ●Silverado, California 92676 ●[phone] ●com-power.com
REV051517
7.0 Warranty
Com-Power warrants to its Customers that the products it manufactures will be free from
defects in materials and workmanship for a period of three (3) years. This warranty shall
not apply to:
•Transport damages during shipment from your plant.
•Damages due to poor packaging.
•Products operated outside their specifications.
•Products Improperly maintained or modified.
•Consumable items such as fuses, power cords, cables, etc.
•Normal wear
•Calibration
•Products transported outside the United States without the prior
knowledge of Com-Power.
In addition, Com-Power shall not be obliged to provide service under this warranty to
repair damage resulting from attempts to install, repair, service or modify the instrument
by personnel other than Com-Power service representatives.
Under no circumstances does Com-Power recognize or assume liability for any loss,
damage or expense arising, either directly or indirectly, from the use or handling of this
product, or any inability to use this product separately or in combination with any other
equipment.
When requesting warranty services, it is recommended that the original packaging
material be used for shipping. Damage due to improper packaging will void warranty.
In the case of repair or complaint, Please visit our website www.com-power.com
and fill out the RMA form (http://com-power.com/repairservicereq.asp). Our
technical assistance personnel will contact you with RMA number. The RMA
number should be displayed in a prominent location on the packaging and on
the product, along with a description of the problem, and your contact
information.