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Presented by Roberto Diana
Gennaio 2014
Understanding PIM and its effects
on network performance
Fundamentals of antenna andcable analysis
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Agenda I
Understanding PIM
Fundamentals and root causes of Passive Intermodulation (PIM)
Intermodulation possibilities in real world scenarios
Active versus Passive Intermodulation
Non-Linear Diode effect at solid state materials
Non-Linear Diode effect at ferromagnetic materials
Intermodulation mathematicsPIM and its dependence on used modulation scheme
PIM calculator
Why is PIM nowadays a problem
What is the goal of PIM fixing
How is PIM measured
PIM impact on other wireless services
PIM root causes
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Agenda II
Understanding PIM
How does PIM look like under real field conditions
Field Examples
Self made PIM sources
PIM indicators in cellular networks
PIM of connector assemblies
PIM Sources within RF interconnections
PIM in Distributed Antenna Systems (DAS)
What is the correct frequency to test PIM?
PIM measurements
PIM versus time
Distance To PIM (DTP)Swept PIM
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Agenda III
Understanding PIM
Guidelines and recommendations
Line Sweep Test (RL, DTF) versus DTP
PIM Master product concept
General function principle of PIM measurements
General function principle of PIM Master MW82119A
Summary
PIM measurements in Distributed Antenna Systems (DAS)
Practical demonstration of PIM measurements
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Intermodulation Possibilities
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Intermodulation
Root Causes for Intermodulation
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Intermodulation
Intermodulation is caused when 2
or more RF carriers are mixed in
an active system and form
unwanted signals
When passive components
containing non-linear elementsthose are the source of this
interference
we refer it in this case as
Passive InterModulation (PIM)
Active versus Passive Intermodulation
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Intermodulation
Non-Linear Diode Effectat passive ferromagnetic metals
How does it work in
passive components ?
A low signal operating in a
linear region and a large signal
operating in the non-linear
region of a ferromagnetic metalis creating additional spectral
components in the output
signal.
B [T]
H [Am-
1]
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Intermodulation
Intermodulation mathematics
Order Frequencies Tone 1 Tone 2
1st Order f 1
f2
100 MHz 101 MHz
2nd Order f 1+f2 f2+f1 201 MHz 1 MHz
3rd Order 2f 1-f
22f
2-f
199 MHz 102 MHz
2f1+f
22f
2+f
1301 MHz 302 MHz
4th Order 2f 2+2f
12f
2-2f
1402 MHz 2 MHz
5th Order 3f 1-2f
23f
2-2f
198 MHZ 103 MHz
3f1+2f2 3f2+2f1 502 MHz 503 MHz
7th Order 4f 1-3f
24f
2-3f
197 MHz 104 MHz
4f1+3f
24f
2+3f
1
9th Order 5f 1-4f2 5f2-4f1 96 MHz 105 MHz
5f1+4f
24f
2+3f
1
e.t.c.
Order Frequencies Tone 1 Tone 2
1st Order f 1
f2
100 MHz 101 MHz
2nd Order f 1+f2 f2+f1 201 MHz 1 MHz
3rd Order 2f 1-f
22f
2-f
199 MHz 102 MHz
2f1+f
22f
2+f
1301 MHz 302 MHz
4th Order 2f 2+2f
12f
2-2f
1402 MHz 2 MHz
5th Order 3f 1-2f
23f
2-2f
198 MHZ 103 MHz
3f1+2f2 3f2+2f1 502 MHz 503 MHz
7th Order 4f 1-3f
24f
2-3f
197 MHz 104 MHz
4f1+3f
24f
2+3f
1
9th Order 5f 1-4f2 5f2-4f1 96 MHz 105 MHz
5f1+4f
24f
2+3f
1
e.t.c.
This is why PIM IMD is so
critical!
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Intermodulation
PIM is a result of signal mixing at nonlinearities
In theory IM3 PIM non-linearity increases at a ratio of 3:1 (PIM tosignal)
1 dB increase in carrier power correlates to a theoretical
increase of 3 dB in PIM signal power.
In practice, the actual effect is closer to 2,3-2,5 dB as the thermal noise
constant -174 dBm/ Hz becomes an error contributor.
f1: 3 2 1 0 1 2 3
f2: 4 3 2 1 0 1 2
IM-Order: 7 5 3 1 1 3 5
3rd Order5th Order7th Order 3rd Order 5th Order 7th Order
f2f122.5
MHz
f1 f2
22.5
MHz
22.5
MHz
22.5
MHz
22.5
MHz
22.5
MHz
22.5
MHz
869
MHz
(Main)
891.5
MHz
(Main)846.5MHz
(PIM)824
MHz
(PIM)801.5
MHz
(PIM)
914MHz
(PIM)936.5
MHz
(PIM)959
MHz
(PIM)
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Intermodulation
PIM multiplies bandwidth
If bandwidth of f1 and f2 is 1 MHz then
BWIM3 = 3 MHz
BWIM5 = 5 MHz
BWIM7 = 7 MHz
PIM are clogging up complete RF bands
f1
f2
fIM7
fIM5
fIM3
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Intermodulation
PIM are clogging up complete RF bands
f1 f2
IM 3IM 5IM 7IM 9 IM 3 IM 5 IM 7 IM 9
200 kHz200 kHz
600 kHz
1 MHz
1.4 MHz
1.8 MHz
600 kHz
1 MHz
1.4 MHz
1.8 MHz
PIM bandwidth increases as carrier bandwidth increases
PIM bandwidth increase with PIM order
IM3 bandwidth = 3
200 kHz = 600 kHzIM5 bandwidth = 5 200 kHz = 1000 kHz = 1 MHz
IM3 bandwidth = 7 200 kHz = 1400 kHz = 1.4 MHz
IM3 bandwidth = 9 200 kHz = 1800 kHz = 1.8 MHz
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PIM Root Causes
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Current increases linearly with
applied voltage
High pressure, metal-to-metal
contacts
Welded or soldered
connections
Current
Voltage
Current
Voltage
Current does not increase
linearly with voltage.
Low pressure, metal-to-metal
contacts
Oxide layers on metal surfacesArcing across small air gaps or
cracks
Linear junctions
Non-Linear junctions
What is a non-linear junction?
PIM root causes
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PIM root causes
Contact Non-Linearities caused by
The contact surface between two conductors are on a micro
scale level concave-convex, for instance only some small
bulges connect to each other. This causes non-uniform surface
currents whereby the contact resistance changes
The conductor surface covers a thin oxidized layer whichcauses the diode effect. When surface voltage reaches a
certain level, the tunnel effect is activated
The non-uniformity rust distribution on surfaces is causing a
non-uniform surface current density
Soldering contamination and oxide on connection surface etc.
PIM Causes - Contect Non-Linearities
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Loose metal-to-metal contacts
Poorly terminated RF connectors
Metal flakes inside connectors
Loose RF connectors
Metal flashing on rooftops
Loose rivets, screws, etc.Rusty / corroded surfaces
Non-linear materials
Nickel / Steel
Ferrite
What is a non-linear at cell sites?
PIM root causes
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PIM root causes
Loose and / or inconsistent
metal to metal contactsNot enough contact pressure.
Cracked solder joints
Cold solder joints
Scratches or dents at
mating interfacesBurrs
Metal flakes, chips, dust
Improperly formed or sized
parts
Misaligned parts
Rough mating surfaces (saw
cut)
Loose metal to metal contactsLoose or rusty bolts
Ferromagnetic materials
(steel, nickel, etc.)
ContaminationTrapped between mating
surfaces
Trapped between plating
layers
Solder splatters
Dirt or debrisSurface Oxides
Insufficient thickness of plated
metal causing RF heating
Too much or too little torque at
connections
Root Causes of PIM in a real RF environment
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Why is PIM nowadays a problem?
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Simple antennas
Single Polarization
Single Band
Fixed Electrical Tilt
Single bands per feeder
Tx and Rx on separate feeders
Tx/Rx isolation >50-60 dB!
Why is PIM now a problem?
RX 1
TX
RX 2
PIM
-60 dB -60 dB
In the good old days
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Why is PIM a problem today?
More complex antennasDual Polarization
Dual Band
Remote Electrical Tilt (RET)
More RF connections
Multiple bands per feeder
Tx and Rx combined on each feeder
PIM 60 dB ( 1 million times) worse!
PIM
Tx/Rx
900/1800Tx/Rx
900/1800
Today
PIM is not related to Return Loss,
VSWR or insertion loss!!!
It cannot be detected by Line Sweeps
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What is the goal of PIM problem fixing
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Why do we measure IM3?
A A
f1 f2
IM 3
IM3 is the highest magnitude / most accurate to measure
IM3 characterizes the linearity of the system
Reducing IM3 reduces all PIM products
IM 5IM 7IM 9IM 11
IM 3
IM 5 IM 7
BTS Uplink (Rx) BTS Downlink (Tx)
Decrease IM3
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How is PIM measured
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How is PIM measured?
PIM is measuredacc. to IEC 62037-1 Ed. 1 25.05.2012
Passive RF and microwave devices,
intermodulation level measurement -
Part 1: General requirements and
measuring methods
acc. to IEC 62037-2 Ed. 1 07.11.2012Passive RF and microwave devices,
intermodulation level measurement -
Part 2: Measurement of passive
intermodulation in coaxial cable
assemblies
Standard specifies the use of two 20
watt carriers ( 2 x +43 dBm)
Standard and norms
Typ. min. antenna IM3 PIM Spec. < -150
dBc = < -107 dBm
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How is PIM measured?
How is PIM expressed in measurement results
PIM level is often expressed in dBc, therefore carrier power c must be
provided
0 dBm
IM 3
f1 f2
IM 3-143 dBc
Carrier Power
dBc dBm
0 dBcf1 f2
-100 dBm
+43 dBm
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How is PIM measured?
PIM level relative to measurement power (heuristic approach)
IEC 62037 defines PIM measurement for passive components
(outdoor use)
In-Building components are often not specified for such high power
levels.
They may be damaged when measured with >20 W.
Each dB reduction in carrier power reduces PIM measurementresults approximately by 2.5 dB.
Example:
A spec of -140 dBc measured with 2 x 43 dBm
is equivalent
to -107.5 dBc at 2 x 30 dBm measurements.
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How is PIM measured?
PIM level relative to measurement power (heuristic approach)
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PIM impact on other services
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PIM impacts several services
PIM order versus RF band
Potential high risk to interfere with other
services
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PIM impacts UL-bands of other services
A real example GSM 900 and DCS 1800 networks
By changing TX frequencies you can avoid interference on used RXchannels
Hard to get realized in densely congested spectrum
Example
f1 = 930 MHz, 200 kHz GSM TX
f2 = 958 MHz, 200 kHz GSM TX
fIM3 = 902 MHz (within RX-band)
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PIM impacts UL-bands of other servicesWhy is PIM crucial for GSM service
GSM system is a noise limited systemwhich link budget is based on Eb/N0 in RXEb = Bit Energy, it represents the amount
of energy per bit.
N0 = Noise Spectral Density, unit is
Watts/Hz (or mWatts/Hz)
Eb/N0 = Bit Energy on the Spectral Noise
Density, unit dB
Assuming RX Noise Figure = 5 dB,
RX Sensitivity = -112 dBm in order to
achieve an Eb/N0 = 6-8 dB
(full rate speech coder)
Any PIM Noise generated has to be
significantly lower than -110 dBm in
order not to degrade receiver sensitivity
Required PIM Noise
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PIM impacts UL-bands of other services
Eb/E0 dependency on process gain
After despreading, the baseband (own) signal needs to be typically afew dB above the interference and noise power.
This required signal power density above the noise power density
after despreading is designated as Eb/No.
This quantity is of capital importance because the quality targets are
always expressed as a function of Eb/No as can be seen in the
analysis presented in where the Bit Error Rate probability is derivedin terms of this figure.
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PIM impacts UL-bands of other services
The principle of process gain
As a rule of thumb you can count of the following figures:
Node B: -121 dBm
Mobile: -117 dBm
For example Ericsson receiver sensitivities:
NodeB CS 12,2 -124 dBm
PS-64 -119 dBm
PS-128 -115 dBm
PS-384 -115 dBm
UE CS 12,2 -119 dBm
PS-64 -112 dBm
PS-128 -110 dBm
PS-384 -105 dBm
HSPDA -95 dBm
http://de.slideshare.net/syedus
ama7/umts-interview-qa
BER of 10-3
Required PIM Noise
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PIM impacts UL-bands of other services
Why is PIM crucial for LTE service
LTE system link budget is based on Resource Block (RB)
One RB = 180 kHz
(12 Sub Carriers x 15 kHz each)
Thermal Noise of one RB = -121 dBm
Assuming eNode B receiver Noise Figure = 2 dB,RX Sensitivity = -119 dBm
Any PIM Noise generated has to be significantly lower than -119
dBm in order not to degrade receiver sensitivity
Required PIM Noise
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How does PIM look like under real field
conditions
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Broadband interference Narrow band spikes
What does PIM look like at the site?
What does PIM look like to the operator?
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What does PIM look like to the operator?
High average
noise level
Lower average
noise level
QUIET
BUSY
QUIET
BUSY
PIM Repair
Number of lost or dropped calls or enhanced data speed is
converted immediately to money
A good way of churn management
PIM service is a good way of churn management
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What does PIM look like to the operator?
Typical cell- and service layout in Stuttgart area
GSM 900
GSM 1800
UMTS 2100
10564
10588
10612
LTE 800
LTE 2600
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What does PIM look like to the operator?
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A real example PIM within GSM 900 band
PIM
What does PIM look like to the operator?
Trouble-free MSn
After switching on the
TRX, you can see an
increased noise increase
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Bad real world field examples
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Poor cable
preparation Dirt /
trash
PIM Field Examples
Field Examples
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PIM Field Examples
Field Examples
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PIM Field ExamplesField Examples
Plenum cable is hollow. Metal particles can fall inside and create PIM.
Hack saws and files MUST NOT be used! PVC pipe cutter provides aclean cut.
Clean cable ends during with isopropyl alcohol during cable prep
Cover unterminated cable ends with plastic caps or electrical tape
Bad flares, ragged cuts, plating damage can result in poor PIM
iBwavesin-buildingtalkswebinarseries07-2013
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PIM Field Examples
Defect main feeder connector
Poor connecter preparation found as PIM
source
Field Examples - Defect Connector
Before connector
replacement
After connector replacement
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PIM Field Examples
Field Example - Defect Connector and its immediate influence
after repair
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Self made PIM sources
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Self-made PIM sources
If you need a PIM source, then
Nut, Bolt & Washer:
On string in front of antenna
Moving in the wind
> 60 dB variation
Steel wool:
Resting on box in front
of antenna
Rocking slightly in the wind
> 9 dB variation
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PIM indicators in cellular networks
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PIM in a Cellular Network
Intermodulation products generated byTX signals can interfere in the RX band.
The common result is that these IMs
can over-power receive channels.
Calls are dropped or
Channels are believed to be occupied
and being used by the BTSLoss of Air Time and thus ARPU
Cell Coverage shrinks
Reduced battery life time
Data Transmission rate drops
RX control loop shows no problem
Antenna sweep detects no issue
RX Noise Level is high
Indicators
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PIM Summary
Macro BTS PIM is of particular concern when
PIM products fall in the RX band
Two or more transmitter channels
share a common antenna
TX signal levels are high
RX sensitivity is high
TX and RX are diplexed
Summary of the phenomenon
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PIM of connector assemblies
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PIM of connector assemblies
Example: PIM difference between hand-tightend and torque specified
900 MHz band signals with 25 MHz tone separation and each 10 W
carrier power
hand-tightened connector IM3 = -115,3 dB
25 Nm torque-tightened connector IM3 = -173.1 dB
PIM performance of DIN 7/16 connectors
The PIM level of a connector depends on
material, power and torque
DIN 7/16 coax cable connectors
typically PIM values of -140 to -168 dBc
recommended torque (IEC) 35 Nm, in practice often 25 -30 Nm
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Loose connector
PIM of connector assemblies
PIM of a connector cable assembly
Fastened connector
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PIM Sources within RF interconnections
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PIM sources within the RF interconnection
Co-Siting GSM 900 / GSM 1800 / UMTS
Copyright@Kathrein Corporation
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PIM sources within the RF interconnection
Co-Siting 3 Op GSM 900 / GSM 1800 and 4 Op UMTS
Copyright@Kathrein Corporation
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PIM sources within
Distributed Antenna Systems (DAS)
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PIM sources within the DAS RF
interconnectionDistributed Antenna Systems (DAS) easy on the first glance
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PIM sources within the RF interconnection
Distributed Antenna Systems (DAS) not easy on the first glance
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PIM sources within the DAS RF
interconnectionDistributed Antenna Systems in reality sometimes a real challenge
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PIM in DAS
Indoor Antenna Radiation Pattern
700 MHz
1900 MHz
Typical indoor antennas are electrically
small:
700 MHz: = 16 , Antenna < wavelength
1900 MHz: = 6, Antenna > 1 wavelength
Higher side & back radiation at lower
frequency
Sharper radiation pattern at high frequency
Will PIM accepted antenna produce PIM
in indoor environments?
How to reduce back radiation?
Will there be an improvement on installedPIM?
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PIM in DAS
There is another problem that has not been seen in the past
Indoor environments present a PIM
challenge.
PIM producing metal objects abound!
Light fixtures
Ductwork
Ceiling tile frames
Structural steel members
Rebar (in concrete)
PIM survey test to evaluate antenna location
Use antenna that will be installed
Use portable, low PIM mount
Move antenna to find optimum spot
Ongoing PIM survey investigations:Optimum test power to use?
Which frequency bands to use?
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PIM in DAS
PIM created by elevated ceilingsAmazingly high magnitude PIM sources can be found indoors
-80 dBm with 1 W test tones (2 x 30 dBm)
Equivalent to -41 dBm (-84 dBc) with 20 W test tones (2 x 43
dBm)
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PIM in DAS
1900 MHz
Small changes in antenna location can have large impact on PIMRF absorber behind antenna has proven beeing very effective to
reduce PIM
With Absorber, PIM reduced by 40 dB !!!
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What is the correct frequency to test PIM?
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Yes, it does partially
Selective antennas
Tower Mounted Amplifiers (TMA)
Combiner, Duplexer, Filter
Lightning surge protectorsLine Sweep test to verify
Use correct PIM test set
By-pass frequency limiting devices
What is the correct frequency to test PIM?
Does it matter at what frequency I test at?
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Yes, it does partially in case of
Selective antennas
Tower Mounted Amplifiers (TMA)
Combiner, Duplexer, Filter
Lightning surge protectors
By-pass frequency limiting components
What is the correct frequency to test PIM?
Does it matter at what frequency I test at?
Yes, it does partially in case of
Line Sweep test to verifyUse correct PIM test set
No, it doesnt in case of
cable and connector measurements
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What is the correct frequency to test PIM?
Does the variation really matter?
Assuming 15 dB reduction in PIM per order (conservative)
Yes, if IM3 or IM5 falls in your RX band
Variation is significant
Measure using same band producing the IM3 or IM5 interference
No IF only higher order products fall in your RX band (IM7, IM9, etc.)
Variation is literally in the noise
Measure using any band that passes through the system
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PIM Measurements
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PIM versus Time
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PIM Measurements
PIM versus time is not static there is a dynamic behavior
PIM magnitude vs. time
Tapping on DUT reveals
real behavior
Excellent visual indication ofPIM stability
Peak PIM held for Pass/Fail
Tapping on RFconnections
Limit Line
Static Test
Tests the base PIM performance
of Cable and Connectors
Dynamic Test
Detect lose contacts in
connectors
Detects contamination in the
connection
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Distance-To-PIM Measurements
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PIM Measurements
DTP - Measure PIM level and location
Shows PIM along a cable
and in an antenna, readout meter
DTP can also measure PIM beyond
an antenna (such as a nearby rusty
cabinet)
Pinpoints bad spots like DTFSetup is very similar to DTF
Unlike PIM, DTP must be calibrated
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PIM Measurements
Measure PIM level and location in a DAS
PIM sources seen at:
0 m
45 m
86.6 m
PIM at test point
reduced by tightening
7/8 connector back nut
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PIM of Radiating Cables
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PIM of Leaky Cables
Radiating cable is sensitive to PIM sources close to the cable.
It doesnt help the fact cables are going to be installed in tunnels
and subway systems near many other metal objects
In this case Distance-to-PIM (DTP) technology
DTP can accurately locate PIM sources along a radiating cable
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PIM Measurements
Measure PIM level and location in Leaky Cable
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PIM Measurements
Finding of hidden and unknown PIM sources
Using Distance-to-Fault to Verify Antenna Location
Using Marker and Delta Marker to Identify Distance-to-PIM beyond
the Antenna
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DTP Measurements
Finding PIM sources beyond the antenna
No need to do this time-consuming and thus expensive job if you useAnritsu Distance-to-PIM (DTP)
Once you have verified the antenna position, use a Delta Marker to
Identify Distance-to-PIM beyond the Antenna
Antenna position? How?
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PIM Measurements
Finding PIM sources beyond the antenna
Concealment site
Antennas hidden inside roof
Possible PIM in front of the
antenna
HiddenAntennas
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PIM Measurements
DTF from VNA, BTS Master
DTP from PIM Master
Be sure to:
Set same start / stop distances
Set same propagation velocity
Calibrate both units at end of
test lead
Set DTF start / stop frequencies:
High bands: 698-896 or 791-960
Low bands: 1710-2170
Low PIM
Termination
PIM
Source
PIM
Source
DTF from VNA, BTS Master
DTP from PIM Master
Be sure to:
Set same start / stop distances
Set same propagation velocity
Calibrate both units
Set DTF start / stopfrequencies:
High bands: 698-896 or 791-960
Low bands: 1710-2170
If possible, sweep as broad as
possible
DTF vs. DTP Overlay with Line Sweep Tools (LST)
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PIM Measurements
DTF vs. DTP Overlay with LST
overlay previous DTF with actual DTP measurement and reveal veryprecise any kind of potential PIM source
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PIM Measurements
DTF vs. DTP Overlay with LST
overlay previous DTF with actual DTP measurement and reveal veryprecise any kind of potential PIM source (1710 2170 MHz)
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PIM Measurements
DTF vs. DTP Overlay with LST
overlay previous DTF with actual DTP measurement and reveal veryprecise any kind of potential PIM source
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PIM Measurements
DTP in different RF bands
the more sweep bandwidth the higher the resolution
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PIM Measurements
DTP in different RF bands
Resolution = ability to resolve closelyspaced PIM sources
Resolution = (150 * vp) / Sweep
Bandwidth
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PIM Measurements
DTP in different RF bands
Too many variables impactaccuracy
Propagation velocity errors
Signal magnitude
Resolution confusion
Electrically long devices (TMA, filters)
Big PIM sources can mask smaller
PIM sources
Remove largest PIM source & repeat
3,5 m
VF = .80
VF = .88
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PIM Measurements
DTP with enhanced resolution
2 x improvement in resolution!
Predictions clearly marked by
red bars on life trace
Location for each prediction
automatically displayed
Speeds DTP trace interpretation
Standard resolution
reports
one PIM source at 16.7 m
Enhanced resolution reports
two PIM sources, 15.7 m and
17.4 m
0m18 m16 m
load
2m16m
2 x PIM sources
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DTP with enhanced resolution
PIM sources 3 m separation
PIM sources 6 m separation
MW82119A-0700
MW82119A-0700
MW82119A-0900
PIM sources 5 m separation
MW82119A-0900
PIM sources 3 m separation
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Swept PIM Measurements
PIM M
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PIM Measurements
PIM levels for individual components combine to give a system PIMlevel.
Combination is similar to the case of system VSWR, except that
feeder and jumper losses provide more padding for far end
components because of the non-linear nature of PIM generation
(typically 2.5 dB variation per 1 dB of carrier variation for 3rdorder).
For example, a 2 dB feeder loss will improve the apparent antennareturn loss as seen on the ground by ~4 dB, but will improve the
apparent PIM by about 7 dB.
PIM contributions from the various components will usually
combine in random phase for a typical system level, which can be
calculated.
But there can be favorable or unfavorable phase combinations togive variations up to a worst case value.
System PIM Level a need for swept PIM measurements
PIM M t
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PIM Measurements
Swept PIM measurements
f1 fixed, f2 swept
f2 fixed, f1 swept
PIM magnitude vs. frequency
shows worst case PIM level
in this example ~13 dB
variation due to phasing!
Multiple PIM signals on combining inand out of phase
13 dB
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Guidelines and Recommondations
G id li & R d ti
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Guidelines & Recommondations
Guideline for PIM testing at the component and system level
Typical PASS / FAIL criteria
Recommendations based on Florida Network US
Test CaseAcceptable Range
@ 2 x 20 W (43 dBm)
Required RF System Maintenance
(coaxial, Antenna, etc,..)
RX Noise Impact
(dBm]
New site installation -140 > PIM > -159 dBcNothing
minimal impact-97 > N > -116 dBm
Existing (aged) site -123 > PIM > -139 dBcOptional
Capacity & Coverage
-80 > N > -96 dBm
Site shows poor performance -100 > PIM > -122 dBcMaintenance Request
Service is affected-57 > N > -79 dBm
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Is there a preferred test process?
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Line Sweep Test (RL, DTF) versus DTP
PIM Measurements
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PIM Measurements
What can you detect with a Sweeper and / or PIM Tester
RF System Problem Detection PIM RL RL (DTF/TD)
Open Circuit Maybe Yes Yes
Short Circuit Maybe Yes Yes
Deformed Coax Cable Probably Yes Yes
Loose connection Yes Probably Yes
Water ingress Probably Probably Yes
Corrosion Yes Probably Probably
Poor material / components Yes Probably Yes
Contaminations (fil ings, wi re edge, plating flecks) Yes No No
Poorly fitting coaxial cable and connector surface Yes No No
Spark marks in surface (from hot disconnects) Yes No No
Dielectric material between coax-cable & connector surface Yes No No
Split in flare due to over-tightening Yes No No
Cracked Solder Joint Yes No No
Internal antenna faults, loose screws, cracked joints Yes No Probably
Small cracks in coaxial cable Yes No No
Loose braid in jumper cable Yes No No
Cell ageing Yes No No
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PIM Master product concept
Anritsu PIM MasterTM
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Anritsu The Solution BoxAnritsu PIM MasterTM
The fastest way to pinpoint the source of PIM
Parameter Specification
Small size: 350 x 314 x 152 mm
Light weight: 9 kg to 12 kg
Batteryoperation: >3.0 hours
Wide power range: 25 dBm to 46 dBm
(0.3 W to 39.8 W)
Residual PIM: -117 dBm @2x 43dBm
-125 dBm typical
Distance-to-PIM: YES
PIM vs. Time: YES
Swept PIM: YES
Noise floor: YES
Remote Control: YES
GPS option: YES
Anritsu PIM MasterTM
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Anritsu The Solution BoxAnritsu PIM MasterTM
Available frequency models
Frequency Model Number F1 F2 IM
700MHz (L/U) MW82119A-0700 734.0 734.5 MHz 745.0 766.0 MHz698.0 716 MHz
779.5 804 MHz
800 MHz MW82119A-0800 791.0 795.0 MHz 811.5 821.0 MHz 832 862 MHz
850 MHz MW82119A-0850 869.0 871.5 MHz 881.5 894.0 MHz 824 849 MHz
900 MHz MW82119A-0900 925.0 937.5 MHz 951.5 960.0 MHz 880 915 MHz
1800 MHz MW82119A-0180 18050. 1837.5 MHz 1857.5 1880.0 MHz 1710 1785 MHz
1900 MHz MW82119A-0190 1930.0 1932.5 MHz 1950.0 1990.0 MHz 1870 1910 MHz
1900/2100 MHz MW82119A-0192 1930.0 1935.0 MHz 2110.0 2155.0 MHz 1710 1755 MHz
2100 MHz MW82119A-0210 2110.0 2112.5 MHz 2130.0 2170.0 MHz1920 1980 MHz
2050 2090 MHz
2600 MHz MW82119A-0260 1930.0 1932.5 MHz 1950.0 1990.0 MHz 1870 1910 MHz
Anritsu PIM MasterTM
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2 to 3 hour Battery LifeReplaceable
Same as other Anritsu HHs
Production tested for reliability
50 hour burn-in
2 hour thermally cycled
Designed tested for reliability
HALT Test
Vibration Test
Shock Test
Drop Test
Designed and tested like all Anritsu Handhelds
Anritsu PIM MasterTM
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Optional Transit case
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Optional Transit case
Space for PIM Master inside
soft case
Storage boxes
Contents shown for
example only
Retractable handle
Foam padding to protect
contents
4x snap latch
Impact resistant, hard
case
Lifting handles
Weather seal760-259-R
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Optional Backpack Accessory Kit
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Optional Backpack Accessory Kit
2000-1746-R
ContentAnritsu Backpack (P/N 67135),
PIM Test Cable (P/N 2000-1626-R),
Low PIM Termination (P/N 2000-1724-R),
PIM Standard 1800 MHz (P/N 1091-390-R),
2 x Low PIM Adapters (P/N 1091-425-R),
2 x Low PIM Adapters (P/N 1091-426-R),
Low PIM Adapter (P/N 1091-427-R),
Cresent Wrench (P/N 01-510),
Torque Wrench (P/N 01-513-R),
Isopropyl Wipes (P/N 971-9-R),
Tapered double tip swabs (P/N 971-10-R)
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PIM Master Equipment Verification Process
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PIM Master Equipment Verification Process
Level compatibility between PIM Standard 900 MHz and 1800 MHz
PIM Master Equipment Verification Process
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PIM Master Equipment Verification Process
Level compatibility between PIM Standard 900 MHz and 1800 MHz
PIM Master What do you need?
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Batteries / charger
One battery comes with PIM
MasterTwo spares + external charger
enables continuous use
Transit caseWeather protection
Shock protection in
vehicle
Shipping container
Accessory kit
Anritsu kit is a PREMIUM kitCustomer may already have
this!
Okay to use existing kit
Recommended configuration
PIM Master What do you need?
PIM Master What do you get for free?
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Anritsu The Solution BoxLine Sweep Tools Documentation (LST)
Line Sweep Tools enable to
Collect traces from the
instruments
Verify that the traces are
correct using markers and
limit lines
Report results in industry
accepted PDF and/or DAT file
format
Line Sweep Tools features
Marker and limit line presets
Quick file name, trace name,
and sub-title renaming
Automated report generation
PIM analysis and reportingcapability
LMR Master and VNA Master
Field Mode compatibility
PIM Master What do you get for free?
PIM Master What do you get for free?
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Line Sweep Tools Documentation (LST)
Reporting after measurementhas been done in order to
secure service payments
Report Generation with
Line Sweep Tools
PIM Level versus time
Distance-To-PIM
Return Loss
Distance-to-Fault
Insertion Loss
PIM Master What do you get for free?
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General Function principle of PIM
measurements
General Function principle of PIM measurements
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General Function principle of PIM measurements
Prior conventional way to measure PIM during the good old days
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General Function principle of MW821xA
General Function principle of MW821xA
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General Function principle of MW821xA
F1 & F2 can be any frequency
power produced goes into load
Fans required to remove heat dissipated in load
IM RX
Duplexer
Load
Receiver
F1 (40W)
F2 (40W)
(2x 20W)
(2x 20W)
TX
Hybrid Combiner
How does MW821xA PIM test equipment work?
How does MW821xA PIM test equipment work?
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A hybrid combiner design utilizesa 3 dB quadrature hybrid coupler
to split the two input signals F1and F2 equally between the two
output ports of the coupler.
Advantages of this approach
include small size, low cost and
broad operating bandwidth.The disadvantage of a hybrid
combiner is power consumption.
Since the hybrid coupler splits
one half of each signal between
the two output ports of the
device, it requires two times the
input power to achieve a given
output level.
How does MW821xA PIM test equipment work?
Hybrid Combiner
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General Function principle of MW82119A
General Function principle of MW82119A
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p p
IM RX
Duplexer
Receiver
F1
F2 TX
Inject two test tones into a system
Tightly controlled frequencies
High power (2 x 20 W typical)
Measure & report the magnitude of the IM produced
Tx combiner
Load
DUT
Must be
low PIM !
PIM
How does MW821xA PIM test equipment work?
How does MW82119A PIM test equipment
ork?
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A filter combiner design utilizes
cavity band-pass filters toefficiently combine signals from
two neighboring frequency bands
onto a common output port.
Advantage very low insertion
loss
Disadvantage - is size, weight,cost and frequency bandwidth.
Filter combiners do not allow all
frequencies in the downlink band
to be selected for PIM testing.
Rather, a space or guard band is
required to achieve isolation
between neighboring frequencybands
work?Filter Combiner
How does MW82119A PIM test equipment work?
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The MW82119A is designed tomaximize the range of IM3
frequencies that can be generated in
the uplink band using F1 and F2 test
signals from the downlink band of
that system.
Placing F1and F
2at the farthest
allowable spacing will identify the far
limit of the IM3 range.
Lowest possible IM3 frequency
q p
TX test tone range setting
How does MW82119A PIM test equipment
work?
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The MW82119A is designed tomaximize the range of IM3
frequencies that can be generated
in the uplink band using F1 and F2test signals from the downlink band
of that system.
Placing F1 and F2 at the farthest
allowable spacing will identify the
far limit of the IM3 range.
The near limit to the IM3 range
coincides with the near limit of the
uplink band itself.
Highest possible IM3 frequency
work?TX test tone range setting
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Summary
Passive Intermodulation Measurements
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PIM = reduces site performance
PIM sources can be eliminated / minimized through:
Careful construction techniques
Use of low PIM components.
Careful site design.
PIM testing should be dynamic (not static)
PIM testing AND Line Sweep testing (VSWR) are
needed to
verify system performance.
EDUCATE and TRAIN installation personal on PIM
and PIM Prevention
Summary Statement
Passive Intermodulation Measurements
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1 dB improvement in receiver sensitivity canmean as much as 11% fewer radio base stations
All the time a question of CAPEX and OPEX
Source: Harri Holma and Antii Toskala, WCDMA & UTMS Nokia
Finland 2004. publisher John Wiley and Son USA
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Practical PIM measurements
Practical demonstration
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Lab demonstration I
To be measured
Uplink spectrum
RL / DTF
PIM level versus time
DTP
Swept PIM
(eventually)
DTF versus DTPoverlay10 m
6 m
6 m
Further on
Is there a differencebetween hand tight
and torch wrench?
Where is my antenna?
Do I have PIM in front
of the antenna?
RG214 cable
Practical demonstration
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Lab demonstration II
To be
measuredSame as
before
(50 LOAD)
10 m
6 m
6 m
Further on
What is the impactof the TMD?
TMD 900/1800
K 80010667
VPol Panel 872960 907.5dBi
Practical measurement demonstration
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M1 PIM vs Time Complete antenne lineM2 PIM vs Time Antenna removed and feeder line with PIM Load
terminated
M3 DTP of M2
M4 DTP enhanced of M2
M5 PIM Source at 16 m removed
M6 TMD exchanged against a new one, result: less PIM
next removed, because TMD input port is creating PIM
M7 Antenna reconnected
M8 Antenna with steel wool on radome
M9 Antenna swapped against another type (Kathrein)
M10 Antenna with close by located clotheshorse with attached steelwool
Practical demonstration
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Residual PIM level measurement
Practical demonstration
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Uplink noise floor measurement
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Practical demonstration
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Distance-to-PIM parameter settings
Practical demonstration
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PIM vs Time of entire feeder line including antenna
Practical demonstration
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Antenna removed and feeder line terminated with PIM Load
Practical demonstration
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DTP
Practical demonstration
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Enhanced DTP
Practical demonstration
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PIM source at 16 m removed
Practical demonstration
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TMD first swapped and then removed
Practical demonstration
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Antenna reconnected
Practical demonstration
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Antenna with steel wool on radome
Practical demonstration
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Antenna swapped against a Kathrein type
Practical demonstration
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Antenna swapped against a Kathrein type
Practical demonstration
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Antenna with close by clotheshorse and attached steel wool
A l l h h d h d l l
Practical demonstration
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Antenna close to clotheshorse and attached steel wool