A.H. Systems SAS-542 User manual

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
1
SAS-542
Biconical Antenna
Operation Manual

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
2
TABLE OF CONTENTS
INTRODUCTION
Introduction ................................................................................................................ 3
Optional Equipment ....................................................................................................4
Intended Purposes......................................................................................................5
OPERATING INSTRUCTIONS
Assembly Instructions ................................................................................................6
Mounting Instructions.................................................................................................. 6
SPECIFICATIONS
Specifications ............................................................................................................. 8
Typical Data................................................................................................................9
Calculations ..............................................................................................................10
Convertion Factors.................................................................................................... 11
MAINTENANCE
Maintenance Procedures .........................................................................................12
Annual Calibration..................................................................................................... 12
Warranty....................................................................................................................13

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
3
INTRODUCTION
The A.H. Systems SAS-542 Folding Biconical antenna operates efficiently over the
frequency range of 20 MHz to 330 MHz. Compact in size, this BiconicalAntenna is an ideal
for use in a shielded room or anechoic chamber. The antenna balun is designed using as
unbalanced to balanced transformer for improved linearity response and is the standard
workhorse of any EMC compliance test house.

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
4
OPTIONAL EQUIPMENT
The following is a recommend accessory list for the SAS-542 Biconical
Antenna:
CONNECTING ACCESSORIES:
SAC-213 –RF cable
Standard 3 meter N(m) to N(m) RF cable made with RG-58/U. Other cable
types available upon request.
PAM-0202 - Preamplifier
With at least 28 dB of gain, this preamplifier is great at improving system
sensitivity for frequencies from 20 MHz to 2GHz
Adapters
Need an Adapter? We stock those as well.
MOUNTING ACCESSORIES:
AEH-510 –Azimuth and Elevation Head
Azimuth and elevation head to assist the test engineer in orientating biconical
antenna at the device under test.
ATU-510 –Wooden Antenna Tripod
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.
ATU-514 –Non-metallic Antenna Tripod
This collapsible tripod is built with all non-metallic materials that will not
influence your antenna measurements. TheATU-514 is a no-nonsense antenna
tripod that offers up to 50lbs. (22.6Kg) load capacity and has telescoping legs
with an adjustable center mast to achieve heights up to 2 meters.

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
5
INTENDED PURPOSES
The Biconical 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.

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
6
OPERATING INSTRUCTIONS
ASSEMBLY INSTRUCTIONS
The SAS-542 BiconicalAntenna is shipped with the elements detached from
the balun. Attach each element to the Biconical balun tee assembly.
MOUNTING INSTRUCTIONS
The SAS-542 biconical antenna is supplied with an ABC-B Balun mounting
clamp. TheABC-B has a 1/4-20 mounting holes on the base of the clamp.
Attach the antenna to the ABC-B mounting clamp, 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.
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 biconical antenna is approximately 60 degrees
and it should be pointed or aimed in the direction that the received signal is
coming from.

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
7
OPERATING INSTRUCTIONS
Once the antenna is mounted to a mast or tripod, connect an N-type coaxial
cable from the antenna to a receiver. The cable should be matched to 50 ohms,
relatively low loss and adequately shielded against leakage such as RG-214/U
or better.
The BiconicalAntenna 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.

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
8
SPECIFICATIONS
ELECTRICAL SPECIFICATIONS
Frequency Range .........................................................................20 MHz –330 MHz
Antenna Factor ......................................................................................8.5 to 21 dB/m
Antenna Gain...........................................................................................-22 to 2.8 dBi
Impedance (nominal)............................................................................................. 50
Average VSWR.............................................................................................. 2.0:1 typ.
Maximum Continuous Power..............................................................................1 Watt
Connector ........................................................................................... N-Type (female)
Mounting ...............................................................................................1/4-20 (female)
PHYSICAL SPECIFICATIONS
Weight ...............................................................................................................4.3 lbs.
(1.95 kg)
Size (W x H)...............................................................................................52.75" x 29"
(134cm x 73.7cm)

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
9
TYPICAL DATA

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
10
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

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
11
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)

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
12
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.

A.H. Systems SAS-542 BiconicalAntenna
©A.H. Systems inc. –REV C
13
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.