Parallel Amplifier Stage Isolation Without Load Resistors

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Solution Overview

Problem

Existing broadband amplifier devices are expensive due to the need for a load resistor to handle high powers in case of faulty amplifier stages, and they require separate cooling to prevent overheating, resulting in wasted energy conversion to heat.

Innovation Solution

The amplifier device operates with at least two parallel amplifier stages, featuring an error-monitoring unit that generates an error signal upon failure, which controls a switching unit with a stepping motor to galvanically separate the faulty stage from the rest of the device, eliminating the need for a load resistor and its associated cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a load resistor is used to handle high powers in case of faulty amplifier stages, then the amplifier device can maintain operation with a faulty stage, but the device becomes expensive and requires separate cooling systems

Engineering Contradiction:
Improveoperation continuity with faulty stageVSAvoidcooling system requirement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the load resistor and its associated cooling system from the amplifier device. Instead of using a load resistor to dissipate power from faulty amplifier stages, the invention completely eliminates this component and its cooling requirements, thereby reducing device complexity while maintaining reliability through alternative power handling methods

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs disposable fuses in parallel with each amplifier stage. When a stage fails, the fuse blows to isolate the faulty stage without requiring a robust load resistor or cooling system. This approach uses inexpensive, single-use components rather than expensive, complex cooling infrastructure

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Reliability

If a load resistor is used to convert power into heat in case of failure, then the faulty amplifier stage can be isolated, but energy is wasted and the load resistor becomes expensive

Engineering Contradiction:
Improvefaulty stage isolationVSAvoidenergy conversion to heat
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent converts the harmful effect of wasted energy into a beneficial isolation mechanism. Instead of dissipating power as waste heat through a load resistor, the invention uses fuses that convert the excessive current into a controlled interruption, isolating the faulty stage without energy waste. The harmful high power condition triggers the fuse to open, turning the energy problem into a reliable isolation solution

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

Solution Approach 2:

The patent removes the load resistor that causes energy waste entirely. By extracting this component and replacing it with fuse-based isolation, the system achieves faulty stage isolation without converting useful energy into wasted heat, thereby improving energy efficiency while maintaining reliability

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If a load resistor is used to handle high powers, then the amplifier device can operate with a faulty stage, but the manufacturing cost increases

Engineering Contradiction:
Improveoperation with faulty stageVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive load resistors and cooling systems with inexpensive disposable fuses. Each amplifier stage has a simple fuse that costs far less than a high-power load resistor with its associated cooling infrastructure. This substitution dramatically reduces manufacturing costs while maintaining the ability to operate with a faulty stage isolated

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent extracts and eliminates the expensive load resistor and cooling system components. By removing these high-cost elements and replacing them with simple fuse-based isolation, the manufacturing cost is significantly reduced while reliability is maintained through automatic faulty stage disconnection

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

This solution allows half of the total power to be directed to the connected device while preventing power loss to a load resistor, thus reducing costs and energy wastage, and enabling the amplifier device to operate without a load resistance or active cooling.

Implementation Method 1

a switching unit that comprises a stepping motor, and Separating the at least one faulty amplifier stage galvanically from the rest of the amplifier device by means of the stepping motor causing a movement

Methodology Applied
Scientific EffectStepping motor: Linear Motor

Data Source

PatentEP3742609B1Method of operating an amplifier device and amplifier device
Publication Date: 2025.02.12 ROHDE & SCHWARZ GMBH & CO KG
  • EP3742609B1 patent drawingFigure 1~3
  • EP3742609B1 patent drawingFigure 4~6
  • EP3742609B1 patent drawingFigure 7~8

AI summary

A method of operating an amplifier device (10) having at least two parallel amplifier stages (12) comprises the following steps: - Generating an error signal in case of failure of at least one amplifier stage (12), and - Separating the at least one faulty amplifier stage (12) galvanically from the rest of the amplifier device (10). Further, an amplifier device (10) is described.