A.H. Systems SAS-521-4 User manual

A.H. Systems SAS-521-4 Bilogical Antenna
©A.H. Systems inc. –May 2014
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SAS-521-4
Bilogical Antenna
Operation Manual

A.H. Systems SAS-521-4 Bilogical Antenna
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TABLE OF CONTENTS
INTRODUCTION
Introduction ................................................................................................................ 3
Intended Purposes......................................................................................................4
Optional Equipment ....................................................................................................5
OPERATING INSTRUCTIONS
Assembly Instructions ................................................................................................6
Mounting Instructions.................................................................................................. 6
Operating Instructions.................................................................................................8
SPECIFICATIONS
Specifications ............................................................................................................. 9
Typical Data..............................................................................................................10
Calculations ..............................................................................................................12
Convertion Factors.................................................................................................... 13
MAINTENANCE
Maintenance Procedures .........................................................................................14
Annual Calibration..................................................................................................... 14
Warranty....................................................................................................................15

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INTRODUCTION
The SAS-521-4 Bilogical Antenna (also known as a hybrid log periodic, biconical antenna)
is a lightweight antenna that has been designed to ensure medium gain, low VSWR and
high-power handling capabilities. Constructed of lightweight aluminum, the SAS-521-4
Bilogical Antenna has been manufactured to operate over a very wide bandwidth. With its
high input power capabilities, the SAS-521-4 is ideal for applications requiring the
generation of field strengths. The reduced size of the antenna is preferred to minimize
chamber wallcoupling and increasing the half power beamwidthto a more acceptable angle
that will cover the whole device under test.

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INTENDED PURPOSES
The bilogical antenna is intended for general laboratory use in a wide variety of
industrial and scientific applications and has been designed to be used in the
process of generating, controlling and measuring high levels of electromagnetic
Radio Frequency (RF) energy. It is the responsibility of the user to assure that
the device is operated in a location which will control the radiated energy such
that it will not cause injury and will not violate regulatory levels of
electromagnetic interference.

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OPTIONAL EQUIPMENT
The following is a recommend accessory list for the SAS-521-4 Bilogical
Antenna:
CONNECTING ACCESSORIES:
PAM-0204
This preamplifier has a broad frequency range and at least 22 dB of gain.An
ideal solution for improving overall system sensitivity for various emissions
testing requirements.
SAC-211-0.5
Standard N(m) to N(m) RF cable made with RG-214/U and optional ferrite
loading that can be made to your specified length. Other cable types available
upon request.
Adapters
Need an Adapter? We stock those as well.
MOUNTING ACCESSORIES:
AEH-510
Azimuth and elevation head to assist the test engineer in orientating biconical
antenna at the device under test.
ATU-510
Each tripod leg is independently adjustable in angle and length to facilitate
antenna height setting. The tripod legs have a rubber tip on one end for indoor
or hard surface use, and a metal spike on the other end for outdoor soft surface
(such as dirt) use.
BTE-510
Bilog Tripod Extension is a mounting rod the extends the antenna off of the
tripod to enable both horizontal and vertical testing.

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OPERATING INSTRUCTIONS
ASSEMBLY INSTRUCTIONS
The SAS-521-4 Bilogical Antenna is shipped with the triangle and window
elements removed from the boom; this allows for easy transportation. The
Bilogical Antenna also comes with the LPM-510 tripod mounting adapter that is
already assembled onto the antenna.
Remove the triangular elements and the 3-sided pieces from the case. Attach
the 3-sided pieces to the triangular pieces with the captive screws installed in
the triangular fittings.
Attach the element assemblies (with the 3-sided pieces towards the short log
periodic end) to the Bilogical boom in front of the black balun housing with the
pre-installed captive screws.
MOUNTING INSTRUCTIONS
The model SAS-521-X antennas have a mid-mount adapter supplied with the
antenna to allow mounting at the CG of the antenna. Mounting the antenna to
the extension rod enables the antenna to be used in either horizontal or vertical
polarization.
1. Mount the BTE-510 tripod extension rod to the ATU-510 tripod with the ¼-
20 mounting screw.
2. Mount the assembled antenna to the other end of the BTE-510 extension
rod with the supplied ¼-20 captive mounting screw.
Attach the antenna to the azimuth and elevation head (AEH-510) through the
screw hole in the antenna base. The azimuth and elevation head (AEH-510)
mounts to the tripod (ATU-510) top and allows the antennas to be rotated 360
degrees and tilted between horizontal and vertical polarization. Each tripod leg
is independently adjustable in angle and length to facilitate antenna height
setting. The tripod legs have a rubber tip on one end for indoor or hard surface
use, and a metal spike on the other end for outdoor soft surface (such as dirt)
use.

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Mount the antenna such that the elements are parallel to the ground for
horizontal polarization testing, or perpendicular to the ground for vertical testing.
The horizontal beamwidth of the Bilogical is approximately 45 degrees and it
should be pointed or aimed in the direction that the received signal is coming
from.

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EMISSIONS TESTING MEASUREMENT POINT:
For 3 and 10 meter testing, the measurement is made from the center of the
antenna radiating elements and is annotated by a measurement point sticker (per
ANSI C63.5).
IMMUNITY TESTING MEASUREMENT POINT:
Measurement is made from the tip of the antenna and typically preformed at a 1
meter distance. (3 meters per IEC 61000-4-3)

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OPERATING INSTRUCTIONS
Once the antenna is mounted to a mast or tripod, connect an N-type coaxial
cable from the antenna to a receiver or RF generator. The cable should be
matched to 50 ohms, relatively low loss and adequately shielded against
leakage such as RG-214 or better. For certain applications where an increased
dynamic range is required, an optional preamplifier (PAM-0204) may be used to
increase the total system sensitivity.
The Bilogical Antenna is in the horizontal polarization when the antenna
elements are parallel to the ground, and vertical polarization when the elements
are perpendicular to the ground.
To minimize impedance mismatch errors, it is recommended that high-quality in-
line attenuators be used to reduce reflections. Connect the attenuator at the
antenna end of the transmitting cable, or when receiving connect the attenuator
at the measuring instrument or preamplifier input.
Dress the cables straight back from the antenna connector at least 1 meter
before being dressed vertically down to the ground plane. Signal cables that
are dressed orthogonal to the antenna elements will have minimal coupling to
the antenna field, but the cable shields may carry external currents caused by
impedance imperfections. Also, portions of the cables that are not straight down
or straight back will couple to the antenna fields.

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SPECIFICATIONS
ELECTRICAL SPECIFICATIONS
Frequency Range ............................................................................. 25 MHz –4 GHz
Antenna Factor .........................................................................................7 to 37 dB/m
Antenna Gain (Ave) ....................................................................................-28 to 7 dBi
Maximum Continuous Power........................................................................400 Watts
Impedance (nominal)............................................................................................. 50
Average VSWR.............................................................................................. 1.6:1 typ.
Maximum Radiated Field.................................................................................100 V/m
Connector ........................................................................................... N-Type (female)
Mounting ...............................................................................................1/4-20 (female)
PHYSICAL SPECIFICATIONS
Weight ...............................................................................................................4.5 lbs.
(2 kg)
Size (L x W x H)............................................................................38.3" x 38.5" x 22.2"
(97.3cm x 98cm x 57cm)

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TYPICAL DATA

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CALCULATIONS
EMISSIONS TESTING
Individual calibration data for the log periodic antenna is supplied at appropriate
distances (3, and 10 meter) to comply with various emissions test requirements.
For emissions measurements, add antenna factor plus cable loss to receiver
reading in dBV to convert to field strength in dBV/meter.
Field Strength(dBuV/m) = SA(dBuV) + AF(dB/m) + cable loss (dB)
SA = Spectrum Analyzer or Receiver voltage reading
AF = Antenna Correction Factor
CL = Cable Loss in dB
IMMUNITY TESTING
For Immunity measurements, the generated electric field strength can be
calculated by:
FS = Approximate Field Strength in (V/m)
P = Power in watts
g = Numeric Gain
d = Distance in meters

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TYPICAL CONVERSION FORMULAS
LOG -> LINEAR VOLTAGE
FIELD STRENGTH & POWER DENSITY
dBV to Volts
V = 10 ((dBV –120) / 20)
dBV/m to V/m
V/m = 10 (((dBV/m) -120) / 20)
Volts to dBV
dBV = 20 log(V) + 120
V/m to dBV/m
dBV/m = 20 log(V/m) + 120
dBV to Volts
V = 10 (dBV / 20)
dBV/m to dBmW/m2
dBmW/m2= dBV/m –115.8
Volts to dBV
dBV = 20log(V)
dBmW/m2to dBV/m
dBV/m = dBmW/m2+ 115.8
dBV to dBV
dBV = dBV +120
dBV/m to dBA/m
dBA/m = dBV/m –51.5
dBV to dBV
dBV = dBV - 120
dBA/m to dBV/m
dBV/m = dBA + 51.5
LOG -> LINEAR CURRENT
dBA/m to dBpT
DBpT = dBA/m + 2
dBA to uA
A = 10 (dBA / 20)
dBpT to dBA/m
dBA/m = dBpT –2
A to dBA
dBA = 20 log(A)
W/m2to V/m
V/m = SQRT(W/m2* 377)
dBA to A
A = 10 (dBA / 20)
V/m to W/m2
W/m2= (V/m)2/ 377
A to dBA
dBA = 20log(A)
T to A/m
A/m = T / 1.25
dBA to dBA
dBA = dBA + 120
A/m to T
T = 1.25 * A/m
dBA to dBA
dBA = dBA -120
E-FIELD ANTENNAS
LOG -> LINEAR POWER
Correction Factor
dBV/m = dBV + AF
dBm to Watts
W = 10((dBm –30)/10)
Field Strength
V/m = 30 * watts * Gain numeric
meters
Watts to dBm
dBm = 10log(W) + 30
Required Power
Watts = (V/m * meters)2
30 * Gain numeric
dBW to Watts
W = 10(dBW / 10)
LOOP ANTENNAS
Watts to dBW
dBW = 10log(W)
Correction Factors
dBA/m = dBV + AF
dBW to dBm
dBm = dBW + 30
Assumed E-field for
shielded loops
dBV/m = dBA/m + 51.5
dBm to dBW
dBW = dBm - 30
dBpT = dBV + dBpT/V
TERM CONVERSIONS
dBm to dBV
dBV = dBm + 107 (50)
dB  V = dBm + 10log(Z) + 90
CURRENT PROBES
dBV to dBm
dBm = dBV –107 (50)
dBm = dB  V –10log(Z) –90
Correction Factor
dBA = dBV –dB(ohm)
dBm to dBA
dBA = dBm –73 (50)
dB  A = dBm –10log(Z) + 90
Power needed for injection probe given voltage(V) into
50load and Probe Insertion Loss (IL)
dBA to dBm
dBm = dBA + 73 (50)
dBm = dB  A + 10log(Z) –90
Watts = 10 ((IL+ 10log(V2/50))/10)
dBA to dBV
dBV = dBA + 34 (50)
dB  V = dB  A + 20log(Z)
dBV to dBA
dBA = dBV –34 (50)
dB  A = dB  V –20log(Z)

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MAINTENANCE
MAINTENANCE PROCEDURES
Proper antenna maintenance should include:
•Visual inspection of RF connectors
•Check for bent and loose elements
•Check for loose or missing hardware
•Corrosion near the element joints
At least once a month it is a good idea to wipe down the antenna with a damp
rag.
ANNUAL CALIBRATION
To ensure reliable and repeatable long-term performance, annual re-calibration
of your antennas, preamplifiers and current probes by A.H. Systems
experienced technicians is recommended. Our staff can calibrate almost any
type or brand of antenna.
It is always up to the user to determine the appropriate interval for calibration
certification based on the requirements of the end users specific
test/application. The calibration of EMC antennas is important for those
conforming to compatibility standard. Radiated emissions testing for
electromagnetic compatibility (EMC) requires the measurement of electric field
(E-field) strength, which is compared with a limit level. The output voltage of an
antenna is converted to E-field strength via its antenna factor, the measurement
of which must include the uncertainty components related to that particular
antenna, taking into consideration the environment in which the antenna is to be
used for the testing. Most standards will specify the appropriate interval for re-
calibration of your EMC antenna.
In some cases these antennas are used for a manufacturers pre-compliance
testing, field monitoring, surveillance and/or other applications where the exact
field intensity of the received signal is not of importance. For those customers a
yearly re-calibration is not necessary, however it is recommended that an
interval for maintenance be performed.
For more information about our calibration services or to place an order for
antenna calibration visit our website at http://www.AHSystems.com
or call 1(818) 998-0223.

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WARRANTY INFORMATION
A.H. Systems Inc., warrants that our Antennas, Sensors and Probes will be free from
defects in materials and workmanship for a period of three (3) years. All other products
delivered under contract will be warranted for a period of two (2) years. Damage caused
by excessive signals at the product's input is not covered under the warranty. A.H.
Systems' obligation under this warranty shall be limited to repairing or replacing, F.O.B.
Chatsworth, California, each part of the product which is defective, provided that the
buyer gives A.H. Systems notice of such defect within the warranty period commencing
with the delivery of the product by A.H. Systems.
The remedy set forth herein shall be the only remedy available to the buyer, and in no
event shall A.H. Systems be liable for direct, indirect, incidental or consequential
damages.
This warranty shall not apply to any part of the product which, without fault of A.H.
Systems has been subject to alteration, failure caused by a part not supplied by A.H.
Systems, accident, fire or other casualty, negligence, misuse or normal wear of
materials.
Except for the warranty set forth above, there are no other warranties, expressed or
implied, with respect to the condition of the product or it's suitability for the use intended
for them by the buyer.
For prompt service, please contact our service department for a Return Material
Authorization Number before shipping equipment back to us.