The Importance of Low PIM Components. Author Tony Ramsden, President of Microlab

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1 The Importance of Low PIM Components Author Tony Ramsden, President of Microlab

2 Why are Low PIM Components Important What is PIM, and what causes it? What is the effect of PIM? What can be done to control it?

3 What is Intermodulation? Intended Intermodulation Interaction of 2 or more signals to produce new signals, such as in a mixer which is designed to be a non-linear device. Signals at frequencies A and B mix to produce new signals at frequencies (A+B) and (A-B). If harmonics are also present at 2A and 2B, we ll also see signals at 2A+B, 2A-B, A+2B and A-2B.

4 What is PIM (Passive Intermodulation)? PIM is simply Intermodulation caused by passive components such as: Coaxial Cable and Jumpers Filters, Power Dividers, Couplers, etc. Any RF signal path discontinuity, especially connectors and connections In fact, whenever the RF signal sees a non-linearity, Intermodulation will be produced.

5 Why should PIM be important? The spurious produced by a passive source must be so low level, so why does it matter? The problem occurs in wireless systems because Tx and Rx signals frequently share the same signal path. This means that 2 large Tx signals can mix and produce a spurious in the Rx band where even a very, very small Tx PIM signal can look like an Rx signal.

6 Primary Effect of PIM Unfortunately, the receiver, looking for the true Rx signal sees the spurious as real. If the spurious signal is stronger than the true, then the receiver desensitizes and the call is dropped. As Dropped Calls increase, revenue falls, and Customer Churn increases.!

7 Controlling Passive Intermodulation Starts by having Low PIM components whenever signal levels are large, say >3W Connectors and cables need to be low PIM Signal Combiners should be Low PIM Hybrid Couplers/Matrices or Diplexers Cavity Filters for narrow band Duplexer functions All Attenuators and Terminations must be Low PIM Controlled Installation Torque wrenches! Available in-service signal monitoring and alarms, particularly of dropped calls

8 Critical PIM Areas Signal Combining Systems Neutral Host Combiners Broadband Antenna Signal Combiners High Power Distribution Initial Signal Splitters for In-Building Surge Protection Components High Power Attenuation/Termination Prevent PIM being reflected back

9 So where does Microlab Fit In? Microlab has developed the know-how to design and produce low PIM products In design Choosing the right materials Using PIM friendly interfaces, connectors Minimizing all metal-to-metal contact In manufacture Following processes explicitly, no short cuts! Testing 100% for PIM performance

10 Low PIM Products from Microlab Splitters, Couplers & Tappers Reactive styles using air dielectric are the low PIM choice Stripline, if designed properly, can be low PIM Wilkinson designs are inherently poor PIM, as they include carbon resistor elements Low PIM Attenuators and Terminations Terminator/Attenuator Powers from 10 to 100W Portable Loads for troubleshooting PIM problems

11 Low PIM Signal Combining Products Broadband Diplexers Combine Wireless Bands without appreciable loss Hybrid Derivatives 2 x 2, 3 x 3 and 4 x 4 Hybrid Couplers Simultaneously combine and split signal with minimal loss Neutral Host Combining Systems Assemblies of Diplexers and Hybrids

12 Diplexers to Join Wireless Bands Planar or Cavity? Planar are broadband, low PIM friendly Broadband = Common Off-the- Shelf Designs for Tetra/P25, Cellular, PCS, UMTS, LTE, WiFi including 5.8 GHz Cavity are suited to narrowband needs Narrowband = Usually task specific Difficult to achieve low PIM

13 New Diplexer / MHz Ultra Wideband for Combining Band Extremities BK-12N

14 Diplexer adds Tetra/LMR to Wideband Adds MHz to MHz Low loss, <0.3/0.5 db low band/high band High Isolation, >50 db Low PIM

15 LTE-2600 Low PIM Diplexer Filters Combine to MHz Add to MHz Add to MHz Inject LTE-2600 to existing bands 50 db Isolation 80W 250W/input power Minimal Path Loss PIM <-150 dbc; -160 dbc typ. Small, lightweight

16 Diplexers for WiMAX/WiFi GHz Coming Soon / GHz >50 db Input Isolation Low PIM, <-150 dbc Average Power: >50W Low and >5W High Band / GHz >50 db Input Isolation Low PIM, <-150 dbc Average Power: >20W Low and High Bands

17 700/850 MHz LTE/Cellular Combiner Diplexer Combines MHz with MHz Triplexer adds MHz

18 Low PIM Hybrid Couplers Microlab is the World Leader in Hybrid Couplers for Wireless 2 x 2 is the standard, 4 x 4 is well appreciated 3 x 3 is now becoming known; Also 4:2, 3:1, etc. Hybrids are the Signal Combining Building Block Signals can be very close to each other and yet do not interfere with each other Hybrids do not have the negative aspects of filters Hybrids can be used to enhance filter systems Microlab Hybrids are all High Isolation and Low PIM Combined with low PIM Loads they are an effective way of adding signals which are close together

19 3dB Hybrid Couplers/Combiners Micro Base Stations System A System B Hybrid Coupler A+B 2 A+B 2 Hybrid Coupler allows sharing of antenna distribution network between signals/service providers

20 Basic 2 x 2 Multi-Band Hybrid Couplers Standard for Highest Isolation, 160W for MHz Ultra Broadband Now MHz 400W for MHz Hybrids with Exceptional Performance MHz with >30 db Isolation Narrow and Broad Bandwidths <-150 dbc PIM standard

21 Multi Casting Matrix: MCM 4 Hybrids become an MCM Then a 4 x 4 Matrix New 4 x 4 Hybrid series up to 30 db isolation Low Loss, Low PIM Cover MHz common connector spacing!

22 Wideband 3 x 3 Hybrid Matrices MHz 25 db Isolation Low Loss, Low PIM

23 The General Purpose Combiner Box 4 Low Band ( MHz) Inputs 4 High Band ( MHz) Inputs High Isolation (>22 db in-band; >55 db intra-band) 4 Combined Outputs, PIM <-142 dbc (+43 dbm x 2)

24 Broadband Combiner Box KM-90

25 Expanding the Capability with Tetra Adding Four MHz Inputs with no additional Loss

26 How do we do it?

27 We can even expand up and down! Adding Four MHz and Four LTE-2600 Inputs with No Additional Loss for 16 Channels

28 16 Inputs To Each Of Four Outputs

29 TETRA Combining Box Combines Public and 1 Private Tetra to All Mobile Channels, MHz Alternate could be: One Tetra One GSM-850 One UMTS-2100 One LTE-2600 feeding to two outputs

30 Low PIM Terminations Portable 50W Dual DIN model Hermetic Cable Loads at 10, 30 & 100W Exceptionally low PIM, <-160 dbc <1.1:1 VSWR (>27 db Return Loss)

31 Hybrid Combiners for Low Powers 2:1, 3:1 & 4:1 Hybrids MHz Band Integrated Loads from 3W to 25W Low PIM if required

32 Low PIM Hermetic Hybrid Combiners 80W Broadband Combiner 25 db Isolation Higher Powers and Isolations for narrower bands Single and dual versions, IP67

33 Low PIM Attenuators ( MHz) 30W 100W In-Out now on Opposite Faces New 1 & 1.8 db Attenuation Values N or 7-16 mm Hermetic Attenuators from 1 to 30 db Powers from 30 to 150W Exceptionally low PIM, <-160 dbc <1.2:1 VSWR (>21 db Return Loss)

34 So Why Do We Need Low PIM? Remember, the receiver, looks for the true Rx signal and sees the spurious as real. If the spurious is stronger than the true, then the receiver desensitizes and the call is dropped. As Dropped Calls increase, revenue falls, and Customer Churn increases. The Solution: Use Low PIM Components From Microlab, of course!

35 WTG Regional Technical Contacts for Additional Questions Mr. James Lim - JLim@wtcom.com Mr. Tony Lin - Shanghai, China - TLin@wtcom.com Mr. Steven Shaw - Manchester, UK - SShaw@wtcom.com Mr. Bob Muro - Parsippany, NJ - RMuro@wtcom.com