PIM Master Anritsu Field Testing PIM Solution

Transcription

1 PIM Master Anritsu Field Testing PIM Solution Featuring Distance-to-PIM (DTP) The Fastest Way to Pinpoint the Source of PIM Slide 1

2 Learning about PIM and PIM testing What is PIM? Why do we care about PIM? Why has PIM become a problem? What are the sources of PIM? Where will PIM occur? Using the Anritsu PIM solution Slide 2

3 What Is Passive Intermodulation (PIM)? Passive intermodulation (PIM) antennas connectors cables TMAs diplexers duplexers occurs in passive devices subjected to high power tones The PIM product mixing at device nonlinearities junctions of dissimilar metals, metal-oxide, loose connectors The higher the signal amplitudes the more pronounced nonlinearities the more prominent intermodulations Source: Slide 3

4 Why do we care about PIM? PIM can occur in the Rx band PIM can knock a receiver off the air PIM indications are: 1. Rx Diversity alarms 2. Receiver desensitization (raised noise floor) 3. Excessive dropped/blocked calls 4. Cell site coverage shrinking 5. Complaints of interference from neighboring cell site owners Slide 4

5 Why is PIM becoming a bigger issue? Increasing RF power in the same band Fully loaded sites More RF channels Shared sites Multi-band antenna systems 700/ / / /2100 Wider bandwidth signals UMTS, LTE Aging antenna systems Slide 5

6 What are the sources for PIM? Improper connector care Poor terminations Contaminated connections Not properly torqued Corrosion (rust) in view of antenna can cause PIM Excessive bend radii on cables Poor PIM performance in devices External causes Corrosion/obstruction nearby Changing weather wet & dry Neighboring cell site Rusty rooftops and fences are prime sources of PIM Slide 6

7 At what frequency will PIM occur? Tx Rx PIM frequencies can be calculated F F IM n+m = n*f1 m*f2 (low side) Low Side High Side IM n+m = n*f2 m*f1 (high side) 3rd 3rd IM 3 product is the strongest 7th 5th 5th 7th PIM is a problem when: PIM occurs in Rx band IM >-100 dbm PIM Calculator Carriers F1 and F2 with IM 3 through IM 7 order products Slide 7

8 A closer look at the nature of PIM signals NA Bands Rx Tx EU Bands Rx Tx 700L (12) (20) U (13) U (14) F1 * 1930 F2 * (R/T) (8) Pub Sfty (3) (iden) (1) (5) (7) PCS (2) AWS (4) dbm Pass/Fail Limit 3rd 3rd Pass/Fail Limit -100 dbm 20 to 30 db 5th 20 to 30 db 7th PIM is broadband and always present When PIM is strong enough for the Receiver to detect is when the problems begin 20 to 30 db 5th 20 to 30 db 7th 7x 5x 3x 1x 1x 3x 5x 7x *Double-click graph to change the values of F1 and F2 Slide 8

9 Does it matter at what power I test at? PIM is power sensitive Passes PIM at 20 W Testing at 40 Watts Tests closer to real world powers Sees microscopic arcing connectors (plasma effects - local high fields causing corona) Spots problems 20 Watts can t see Fails PIM at 40 W Note the non-linearity nature of PIM 3 db input power difference (43 46 dbm) yields 7.3 db PIM difference ( dbm) Testing at 40 Watts finds more PIM Slide 9

10 Can you find PIM outside the Antenna System? DUT Cable assembly and antenna PIM sources located at: 2.8 m, 18.0 m, 25.6 m, 34.1 m Distance-to-PIM test results 3.5 m, 18.5 m, 26.4 m, 34.4 m Antenna at 28.7 m External PIM found at 34.1 m, the roof 28.7 m cable Slide 10

11 Can you find PIM outside the Antenna System? DUT Cable assembly and antenna One PIM source 5 m beyond antenna Distance-to-PIM test results PIM source at 8.18 m Antenna at 2.75 m External PIM found at 7.8 m, the cart 50% of PIM reported is external Slide 11

12 PIM Master MW8219A RF Power 2 x 20, 30, or 40 Watts Tx Band 1930 to 1990 MHz (PCS Band) 2110 to 2155 MHz (AWS Band) IMD Band 1710 to 1755 MHz 1850 to 1910 MHz IM Orders 3rd, 5th, or 7th orders PIM Master Top view with easy reference connection diagram Measurements PIM Noise Floor Distance-to-PIM (DTP) Slide 12

13 Troubleshooting with Distance-to-PIM at 1990 MHz Run PIM Test Is there a problem Yes! Measured Marker 1: m Marker 2: m Marker 3: m Run DTP Test Troubleshoot largest PIM source Amplitude Scale db DUT (26 m cable) PIM 3.1 m, 10.7 m, 25.9 m Slide 13

14 Troubleshooting with Distance-to-PIM at 1990 MHz Run PIM Test Is there a problem Yes! Measured Marker 1: m Marker 2: m Run DTP Test Troubleshoot largest PIM source Amplitude Scale db DUT (26 m cable) PIM 3.1 m, 25.9 m Slide 14

15 Troubleshooting with Distance-to-PIM at 1990 MHz Run PIM Test Is there a problem Yes! Measured Marker 1: m Run DTP Test Troubleshoot largest PIM source Amplitude Scale db DUT (26 m cable) PIM 3.1 m Slide 15

16 Troubleshooting with Distance-to-PIM at 1990 MHz Run PIM Test Is there a problem No! Measured Marker 1: m Run DTP Test Save & monitor over time Amplitude Scale db DUT (26 m cable) Potential PIM 10.7 m Slide 16

17 Troubleshooting with Distance-to-PIM at 900 MHz Run PIM Test Is there a problem No! Measured Marker 1: m Marker 2: m Marker 3: m Run DTP Test Save & monitor over time Amplitude Scale db DUT (26 m cable) Slide 17

18 PIM Analyzer Mode Controlled with Handheld PIM Analyzer Mode Listen to tone of PIM level Set Limit Lines for Pass/Fail GPS tag PIM measurements Save and Recall Set-ups Handhelds w/ PIM Analyzer Mode 40 W Residual PIM Measurement Trace view with GPS tagging and pass/fail limit line Site Master S332E, S362E Spectrum Master MS271xE, MS2721B, MS272xC Cell Master MT821xE BTS Master MT822xA/B Slide 18

19 PIM Master CE 인증 Aug 2011 Company Confidential Slide 19

20 If I do a PIM test do I still need to do Line Sweep? Sample report in black and white Both tests are required Two different tests One can pass and the other can fail Measurements PIM linearity Line Sweep impedance Troubleshoots PIM nonlinearities Line Sweep impedance mismatches Slide 20

21 Why PIM Master? 40 Watt testing capability Find PIM where 20 Watts cannot Distance-to-PIM Find the location and magnitude Internal and external PIM sources Controlled by Anritsu Handheld Same instrument for line sweeps GPS-tagging of measurements Complete line of accessories Robust load/termination Adaptors and cables Line Sweep Tools PIM and line sweeps together Common reporting format for both Certified Training Complete training by passing exam Slide 21

22 Slide 22