How can I fix Passive Intermodulation (PIM)

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Joined: Wed Feb 06, 2019 2:16 pm

How can I fix Passive Intermodulation (PIM)

Post by CraigM » Tue Feb 12, 2019 9:13 am

Hi Guys,

I have a mobile radio base station that has passive intermodulation (PIM).
How do I locate the hardware in the antenna system that is causing the PIM ?

Posts: 15
Joined: Thu Feb 07, 2019 9:10 am

Re: How can I fix Passive Intermodulation (PIM)

Post by Tharaka » Tue Feb 12, 2019 9:56 am

Hi CraigM,

I have years of experience assisting field engineers in location and rectify PIM.
Insightus has years of experience locating and rectifying PIM and is regularly and successfully used by vendors and their engineers to fix PIM others can't.

The ease of fixing passive intermodulation (PIM) can range from extremely easy to extremely hard.
The faulty hardware will be in the antenna system from transmitter/receiver all the way to the antennas and can be anything in that path, often more than 1 thing is causing PIM.
To fix you will need to monitor the RTWP/RSSI readings to see the PIM and when it is fixed.

To fault find: (This is simple as. I could write a whole document)
1. Analyse antenna system setup and technologies that do and don't have PIM to minimise potential area for PIM.
2. Insert loads in antenna path of potential area and moniter RTWP/RSSI.
3. Keep using "2" to divide and conquer and continuously reduce potential area of PIM until hardware located.
4. When hardware located then repair or replace.
5. Return to "2" until RTWP/RSSI is normal.

If you have loads at the antenna input connectors and RTWP/RSSI is normal then antenna fault or interferer.
Assumed full load testing to loads whilst monitoring RSSI/RTWP.

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