PIM (Passive Intermodulation) Testing Basics

This page covers PIM (Passive Intermodulation) testing basics. It mentions the PIM tester or PIM Analyzer used to conduct PIM tests of the Base Station Site. Anritsu PIM Analyzer is one of the popular PIM test equipment options. Benefits of PIM Analyzer are also mentioned.

As we know, intermodulation is a kind of distortion produced in the wireless system as a result of more than one frequency getting tapped into an amplifier, mixer, connector, or cable. Let’s understand an example of intermodulation with two frequencies as input. The nonlinear active or passive components generate second and third-order products of these two frequencies (i.e., f1 and f2).

There are two basic types of intermodulation (IM): active IM and Passive IM. The active IM results from mixing more than one frequency signal in the active components, such as RF mixers and RF amplifiers. The passive IM results from mixing frequency signals in the passive components or parts, such as loose contacts between cable and connector, broken connectors, broken cables, passive components with poor VSWR from different vendors in a system, etc.

Out of second and third Intermodulation, third-order distortion is the one that creates a problem in the normal functioning of the wireless system. It is measured by measuring the TOI (Third Order Intercept) Point or 1dB compression point. TOI is also known as IP3.

Anritsu PIM Analyzer Used as PIM Test Equipment

The test equipment used for PIM testing is known as a PIM analyzer. Anritsu Corporation has developed the MW82119A PIM Master, which can be used as PIM test equipment. As it is portable, it is very handy for cellular tower testing requirements.

Following are the features of this PIM analyzer:

• Battery powered (One-time charged battery can run for 2.5 Hrs.)
• Houses an 8.4-inch touchscreen display
• Supports testing of LTE, PCS, DCS, and GSM technologies
• Different models support different frequency bands (700 MHz, 1900 MHz) in the transmit and receive directions
• Allows the user to configure two input carrier frequencies (f1, f2), the order of intermodulation, output power level, duration of the test, upper limit, lower limit, etc.
• Provides PIM vs. time, distance to PIM, and swept PIM measurements

Other PIM Tester or PIM Analyzer Equipments

The following table mentions Other PIM analyzer equipment used as a PIM tester.

Benefits of PIM Analyzer

Following are some of the advantages of PIM analyzer as test and measurement equipment.

1. Identifies PIM sources in cables, connectors and antennas, ensuring optimal network performance.
2. Reduces signal interference, improving data rates, call quality and overall network efficiency.
3. Early detection of PIM issues helps in proactive maintenance, minimizing service disruptions.
4. Provides high precision analysis of PIM levels in dBm.
5. Compatible with different cellular bands (LTE, 5G, etc.).
6. Available in handheld and benchtop models.
7. Ensures Compliance with Industry Standards for PIM levels.

Conclusion

PIM analyzers or test equipment are essential tools for maintaining high performance wireless networks. They help detect, analyze and mitigate PIM related issues, ensuring better signal integrity, reduced interference, and improved customer experience. Investing in a quality PIM tester enhances network reliability, prevents costly downtime and supports seamless wireless communication.