Power-Combining Circuit with Integrated Filters for Spurious Component Suppression

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Solution Overview

Problem

Conventional power combining circuits for high frequency bands, such as VHF and UHF, suffer from signal waveform distortion and generation of harmonics and spurious components due to amplifier non-linearity, leading to potential amplifier failure when these components are reflected back from filters.

Innovation Solution

Incorporating filters with impedance transformation functions at strategic positions in the power combining circuit to remove spurious components without reflecting them back to the amplifiers, using 3dB-hybrid circuits and terminators to manage signal phases and impedances effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If filters are added to remove spurious components, then signal purity is improved, but device complexity increases

Engineering Contradiction:
Improvesignal purityVSAvoidcircuit complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent embeds filter circuits within the hybrid circuit structure itself, where the hybrid circuit serves dual functions as both a power combining device and a filtering structure. The filter elements are integrated into the existing signal path rather than being added as separate external components, thus achieving signal purification without proportionally increasing overall device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The hybrid circuit is designed to perform multiple functions simultaneously: it acts as a power combining circuit for amplifiers while also functioning as a filter to remove spurious components. This multi-functionality eliminates the need for separate dedicated filter circuits, thereby improving signal purity without adding proportional complexity to the device.

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

2Manufacturing precision

If filters are placed to remove spurious components, then signal purity is improved, but amplifier reliability deteriorates due to reflection

Engineering Contradiction:
Improvesignal purityVSAvoidamplifier reliability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent introduces an isolator as an intermediary component positioned between the amplifier and the filter/hybrid circuit. This isolator acts as a mediator that allows the filter to effectively remove spurious components while preventing reflected signals from reaching the amplifier, thus maintaining both signal purity and amplifier reliability through the protective intermediary function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The isolator is positioned to preemptively block reflected spurious components before they can return to and interfere with the amplifier operation. By establishing this protective barrier in advance, the system prevents potential amplifier failure caused by reflected signals while maintaining the filtering function for signal purification.

Inventive Principle:
Principle #9Preliminary anti-action

3Power

If amplifiers operate in parallel to increase power, then output power is improved, but harmful factors increase due to non-linearity

Engineering Contradiction:
Improveoutput powerVSAvoidspurious components
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes spurious components generated by parallel amplifier operation through integrated filter circuits within the hybrid structure. By taking out these harmful frequency components (harmonics and intermodulation products) from the combined signal, the system maintains high output power while eliminating the harmful effects of amplifier non-linearity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the harmful spurious components generated by amplifier non-linearity into a manageable filtering task. The hybrid circuit's filtering function transforms the problem of unwanted harmonics and intermodulation products into an opportunity to demonstrate effective signal purification, where the very components that cause harm are identified and systematically removed by the integrated filter structure.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP2899801B1Power-combining circuit and power-combining method
Publication Date: 2017.10.04 NEC CORP
  • EP2899801B1 patent drawingFigure 1
  • EP2899801B1 patent drawingFigure 2
  • EP2899801B1 patent drawingFigure 3

AI summary

A power-combining circuit at least equipped with: a plurality of amps, named first and second through n-th amps (PA1, PA2-PAn), for amplifying inputted high-frequency power; a plurality of 3dB-hybrid circuits, named first and second through n-th hybrid circuits (HYB1, HYB2-HYBn), for distributing the outputs from each of the amps to two signals for which the phase difference is 90° in relation to one another; two couplers, named first and second couplers (C1, C2), for coupling the signals, among the two signals outputted from each 3dB-hybrid circuit, which are in phase with one another; two filters, named first and second filters (FILTER 1, FILTER 2), for removing a spurious component included in each of the two signals coupled by the couplers; and a back-end-positioned hybrid circuit, named the 0th hybrid circuit (HYBO), for power-combining the signals from the filters and outputting the same. As a result, the provided power-combining circuit is capable of suppressing and absorbing a spurious component produced during power amplification.