Improving wireless Networks Passive Intermodulation - PIM Workshop.pdf · FAIL No tapping Tapping...

Improving wireless

Networks

Passive Intermodulation

Improving Wireless Networks

© Kaelus 2012. All rights reserved.

CONFIDENTIAL AND PROPRITARY INFORMATION OF KAELUS

About Kaelus

• Kaelus designs and manufactures a wide range of innovative RF and

microwave solutions for the wireless telecommunications sector

• Within Smiths Group we rebranded as Kaelus, four existing Smiths trading

entities into a single operating unit in 2010, while preserving the technology

and management of our individual companies

• Kaelus’ experience and understanding of the radio environment enables us

to excel by developing technically differentiated offerings that improve

network performance – Kaelus is an operating unit of Smiths Interconnect Microwave, within Smiths Group, plc.

PIM Test Instruments RF Conditioning Products Site Services


Global Service & Support

Americas EMEA APAC


What is Passive Intermodulation (PIM)?


What is Passive Intermodulation (PIM) ?

PIM = Noise generated by the interaction between the multiple Tx signals and passive non-linear junctions in the RF path.

Increasing the received Noise floor thus reducing base station sites coverage and capacity.

f 1 f 2

f 1 +f 2 f 2 -f 1

2f 1 -f 2

2f 1 2f 2

2f 2 -f 1 3f 2 -2f 1

4f 2 -3f 1

3f 1 -2f 2 4f 1 -3f 2

Interference Interference

Desired

PIM generated products will affect received band (UL) by



For wireless operators

f 1 f 2

f 2 -f 1

2f1 –f2 3f 1 -2f 2

4f 1 -3f 2

Interference

GSM, UMTS, LTE, CDMA, WCDMA

DL - Downlink UL - Uplink

TX frequencies



f 1 f 2

f 2 -f 1

2f1 –f2 3f 1 -2f 2

4f 1 -3f 2

Interference

PIM depends on:

•Number of possible frequency combinations (more frequencies more possible combinations)

•The frequencies TX power ( + 1dBm Tx Power = + 2.5 to 3 dBm on PIM)


TX frequencies


PIM is getting more complex with

f 1 f 2

2f1 –f2 3f 1 -2f 2

4f 1 -3f 2

RX operator 1

By changing the TX frequencies the IM products change


TX operator 1

f 1 f 2

2f1 –f2 3f 1 -2f 2

4f 1 -3f 2

RX operator 1


TX operator 1

GSM900 Example



But now you have GSM900 with UMTS900 or LTE1800

f 1 f 2

2f1 –f2 3f 1 -2f 2

4f 1 -3f 2

RX operator 1


TX operator 1

Not a lot of space to change TX frequencies, a UMTS carrier that normally is 5 MHz or LTE 10 MHz carrier and more combination possibilities

UMTS Or LTE Carrier



Networks evolution towards:

• Indoor or outdoor complex DAS systems (shared by several operators)

• Site sharing with multiple transmit carriers (same RF infrastructure for multiple operators)

• Multi-technology sites (GSM 900 MHz, GSM 1800 MHz, UMTS 2100, UMTS 900 MHz, CDMA 450, LTE800, LTE2600…)

Combining Unit

GSM 900GSM 1800WCDMA

OP

1

BT

S

OP

2

BT

S

OP

3

BT

S

OP

1

BT

S

OP

2

BT

S

OP

3

BT

S

OP

1

No

de

B

OP

2

No

de

B

OP

3

No

de

B

Lo

ad

180

0/W

CD

MA

900/1

800

Triplexer

RF Output ports

PSPS

PSPS

PSPS

PSPS

Outdoor

area

AntAnt

AntAnt

AntAnt

PSPS

AntAnt

AntAnt

Ant

PSPS

PSPS

AntAnt

PSPS

AntAnt

AntAnt

AntAnt

PSPSAntAnt

PSPSAntAnt

PSPSAntAnt

PSPS

AntAnt

Indoor

Area 1

Indoor

Area 2

Indoor

Area 3

Indoor

Area 4

Indoor

Area 5


PIM Sources

Non-linear metal-to-metal contacts:

• Loose RF connectors.

• Poorly prepared RF cable terminations

• Improperly mated / misaligned parts

• Cracked / cold solder joints

• Loose mechanical fasteners (screws, rivets)

Traditional sweep (RL or DTF) testing many times does not identify these problems.


First edition of IEC 62037 was published on 9/16/1999. (>12 years ago!)

Purpose:

To establish a standard test method for measuring Passive Intermodulation (PIM)

Provide a method to compare the PIM performance of different devices

Key recommendations of the specification:

Third Order IM products typically represent the worst case condition of unwanted signals; therefore measuring IM3 characterizes the DUT

PIM comparisons should be done at the same power level. (2x 20 W recommended for mobile communications systems)

Devices should be subjected to an “impact” or “movement” while PIM testing

PIM test specification IEC 62037


IEC 62037 requires that devices be subjected to an “impact” or “movement” while PIM testing. Referred as “Dynamic” testing

Loose mechanical contacts in the field may not generate PIM until subjected to a future environmental stress (thermal cycling, ice loading, wind loading, etc.)

PIM level must stay below the specified maximum at all times during a dynamic test

FAIL

No tapping Tapping

PASS

Poor RF Connection

PIM tests must be dynamic


PIM test process at cell site:


KAELUS PPIM Solutions


Summitek Instruments has been producing “bench top” PIM test systems for more than a decade

Summitek has delivered more than 800 BPIM systems worldwide

These systems have been used by RF equipment manufacturers to reduce PIM in their component designs

PIM testing is not new!


What is relatively new is Portable PIM test equipment.

“Portable” PIM test equipment enables system level testing to be conducted at the cell site.

On site PIM testing reveals:

Installation workmanship issues

Component damaged during installation

Component damaged in transit


• High Power – Premium

• Adjustable power (2 – 20W)

• Adjustable frequencies

• Rugged construction

• Integrated transit case

• Panel PC with touch screen interface, on-board reporting

PIM Test Equipment: iQA Series

CONFIDENTIAL AND PROPRITARY INFORMATION OF KAELUS -19-

• Reduces the time required to troubleshoot and repair a site

– Identifies the location of PIM sources that are present without dynamic testing

– Fix those first, then carry out dynamic testing

Benefits of RTF


• Adjustable power (+0.1 to 20W)

• Highly portable and ruggedized design – ideal for top-of-tower testing

• Includes iPad Mini for safe, hands-free dynamic testing at the top of a tower

• Battery powered

• On board, touch screen interface available for local control

• Includes the Kaelus industry leading report generator

PIM Test Equipment: iPA Series


iPA Passive Intermodulation Analyzer

• Highly portable and ruggedized design – ideal for top-of-tower testing

• Includes iPad Mini for safe, hands-free dynamic testing at the top of a tower

• IEC Specified Test Power: 2 x 20W

• Battery powered

• On board, touch screen interface available for local control

• Includes the Kaelus industry leading report generator


Configurable and Ruggedized for Field Testing

• Designed for indoor, outdoor & tower top testing

• Lifting lugs at either end for hoisting and multiple

hanging and mounting orientations

• Rotating handles for any orientation

• Webbing straps on both sides for comfortable

hand carrying


Wireless Remote Control

• Any Wi-Fi device with a web browser can connect and control the iPA – iPad Mini included with every unit

• Multiple devices can view data while testing as “viewers” or “master controllers”

• Safety master control functionality avoiding inadvertent RF transmission

• Field engineer at the base of a tower can control the unit while tower climber dynamically tests

• View multiple screens on the remote device, e.g. time trace and standard PIM

• iPA acts as an access point providing a secure wireless network utilizing WPA/WPA2 security


-24-

© 2012 Kaelus Inc. All Rights Reserved

www.kaelus.com

Contact Us: Americas +1.303.768.8080

Asia Pacific, Africa +61.(0).7.3907.1200

China +86.21.6084.2200

Europe, Middle East, India +44.(0).1383.437920

Follow @KaelusRF:

Thank you!

Date post:	29-Oct-2020
Category:	Documents
Upload:	others
View:	1 times
Download:	0 times

Improving wireless Networks Passive Intermodulation - PIM Workshop.pdf · FAIL No tapping Tapping...

Documents