Passive Harmonic Test System for PIM Measurement

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Solution Overview

Problem

Existing radio transmission systems face challenges in identifying and reducing passive intermodulation (PIM) interference, which is caused by nonlinearities in passive components, leading to radio signal interference at different frequencies, affecting system performance and requiring complex testing equipment.

Innovation Solution

A harmonic test system with a single frequency test channel is developed, allowing for a handheld, portable unit capable of in-field testing, using a signal generator, antenna system, filter, and analysis unit to measure and determine passive intermodulation magnitude, offering a higher dynamic range and reduced electronic complexity compared to conventional systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a multicarrier NM testing equipment is used, then measurement precision for passive intermodulation can be achieved, but device complexity increases

Engineering Contradiction:

Improvepassive intermodulation measurement precisionVSAvoidtesting equipment complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential function of passive intermodulation measurement from complex multicarrier testing equipment and implements it using a simplified single-carrier system with a signal generator, antenna, and spectrum analyzer, removing unnecessary complexity while maintaining measurement capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a simplified copy of the measurement function by using a single carrier frequency instead of multiple carriers, replicating the essential measurement capability through a different, simpler technical approach that avoids the complexity of multicarrier systems

Inventive Principle:

Principle #26Copying

2Measurement precision

If fixed-location anechoic chamber testing is used, then measurement precision for harmonic sources can be achieved, but ease of operation deteriorates due to portability constraints

Engineering Contradiction:

Improveharmonic source detection precisionVSAvoidportability

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent extracts the harmonic measurement capability from the fixed anechoic chamber environment and implements it in a portable handheld device that can perform measurements in field conditions without requiring controlled chamber environments

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/physical infrastructure of fixed anechoic chambers with an electronic/portable measurement system that uses signal processing and spectral analysis to achieve harmonic detection in practical field conditions

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If conventional testing systems are used, then comprehensive testing capability is maintained, but productivity decreases due to higher electronic complexity

Engineering Contradiction:

Improvetesting capabilityVSAvoidtesting efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent extracts the core testing function from complex conventional systems and implements it in a streamlined handheld device that maintains essential testing capability while eliminating excess electronic complexity that reduces productivity

Inventive Principle:

Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system enables efficient and sensitive detection of harmonic sources, allowing for in-field testing of components and structures without the need for fixed-location anechoic chambers, providing a more efficient and portable solution for PIM testing.

Implementation Method 1

a signal generator (402) configured to generate a test signal (302) having a frequency (f1)

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

a filter (424) configured to remove signals, from a representation of the harmonic source signal, over a bandwidth

Methodology Applied

Scientific EffectFrequency filtering: Filter (electronic)

Implementation Method 3

an analysis unit (408) configured to measure a power level of a second frequency (304) contained in the representation of the signal from the harmonic source

Methodology Applied

Scientific EffectPower measurement:

Data Source

PatentUS11303366B2Passive harmonic test system and method

Publication Date: 2022.04.12 THE BOEING CO

AI summary

Methods and systems for harmonic intermodulation testing are presently disclosed. The test system includes a signal generator configured to generate a test signal having a first frequency. The test system also includes an antenna system configured to transmit a representation of the test signal and receive a harmonic intermodulation signal. The test system also includes a filter configured to remove signals, from a representation of the harmonic intermodulation signal, over a bandwidth that includes the first frequency. The test system also includes an analysis unit configured to measure a power level of a second frequency contained in the representation of the harmonic intermodulation signal. The analysis unit is also configured to determine a passive intermodulation magnitude at any order based on the power level of second frequency.