Two-Port PIM Analyzer for Internal and External Source Localization

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Solution Overview

Problem

Conventional methods for detecting and mitigating passive intermodulation (PIM) interference in wireless communication systems, particularly in MIMO and DAS, are inadequate in distinguishing between internal and external PIM sources, leading to inefficient mitigation strategies and network performance degradation.

Innovation Solution

A two-port PIM analyzer is used to inject test tones into a system, receive response signals, and identify PIM sources by comparing localized peaks to predefined thresholds, distinguishing between internal and external sources through Distance-to-PIM (DTP) measurements and analyzing test cases, enabling precise localization and mitigation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional PIM detection methods are used, then PIM interference can be detected, but the ability to distinguish between internal and external PIM sources is insufficient

Engineering Contradiction:
ImprovePIM source identification accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the PIM detection process into distinct one-port and two-port measurement modes. One-port measurements detect both internal and external PIM sources, while two-port measurements specifically identify external PIM sources. This segmentation allows the system to differentiate between internal and external sources by comparing results from both measurement types, thereby improving source identification accuracy without requiring a single overly complex device.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary classification process that takes raw PIM measurements and applies logical analysis to determine source origin. By using the two-port measurement as an intermediary step that specifically identifies external sources, the system can then subtract these from total PIM measurements to isolate internal sources, improving identification precision through this intermediate analytical layer.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If PIM sources are not accurately classified, then detection can proceed quickly, but mitigation strategies become inefficient

Engineering Contradiction:
Improvemitigation efficiencyVSAvoiddetection and classification time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent performs preliminary classification of PIM sources by executing both one-port and two-port measurements during the detection phase. By classifying sources as internal or external before implementing mitigation strategies, the system enables targeted remediation actions. This preliminary classification prevents wasted time on ineffective mitigation attempts and accelerates the overall productivity of the PIM management process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the measurement parameters by switching between one-port and two-port measurement modes. This parameter change allows the system to gather different types of data that, when combined, provide complete source classification information. The ability to rapidly switch between measurement modes enables efficient classification without significant time loss.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If two-port measurements are performed to identify external PIM sources, then source classification accuracy improves, but measurement complexity increases

Engineering Contradiction:
Improveexternal PIM source identification accuracyVSAvoidmeasurement procedure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent designs the PIM analyzer to perform both one-port and two-port measurement functions using the same hardware platform. This multi-functionality allows the device to execute different measurement procedures (one-port for total PIM, two-port for external PIM) without requiring separate specialized equipment. The universal device handles both measurement types, improving external source identification accuracy while avoiding the need for multiple complex devices.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent inverts the traditional approach by using two-port measurements not as the primary detection method but as a specialized tool for identifying external sources. Instead of starting with complex multi-port measurements and simplifying, the system uses simple one-port measurements for general detection and adds two-port measurements specifically for external source identification. This inverted approach maintains measurement precision for external sources while managing overall procedure complexity.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP4618448A1Two-port passive intermodulation analyzer to classify interference signals and identify likely sources
Publication Date: 2025.09.17 ECSITE INC
  • EP4618448A1 patent drawingFigure 1~3
  • EP4618448A1 patent drawingFigure 4
  • EP4618448A1 patent drawingFigure 5~6

AI summary

Systems and methods of passive intermodulation (PIM) detection in a radio frequency (RF) system including: injecting, from each port of a two-port PIM analyzer, two test tones or a wideband modulated carrier signal into the system one port at a time; receiving, at each port, a response signal from the system in response to the test tones or wideband modulated carrier signal; injecting, from two ports of the two-port PIM analyzer, test tones or a wideband modulated carrier signal into the system; receiving, at the two ports, a response signal from the system in response to the test tones or wideband modulated carrier signal; and identifying one or more PIM sources based on the response signals.