Thermophotovoltaic Antenna Power Aperture Linearization

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Solution Overview

Problem

Existing array antennas face limitations in increasing signal-to-noise ratio due to the non-linear relationship between aperture size and power consumption, particularly in airborne applications where mass and weight restrictions are stringent, leading to a reversal in the power aperture curve as aperture size increases.

Innovation Solution

The implementation of thermophotovoltaic cells to convert waste heat from antenna transmitters into electricity, combined with high-temperature solid-state power amplifiers and monolithic microwave integrated circuits, allows for the efficient recycling of waste heat and reduction in power consumption, thereby maintaining a downward trend in power consumption as aperture size increases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If aperture size is increased to improve signal-to-noise ratio, then radar performance is improved, but power consumption increases non-linearly and eventually reverses the benefit

Engineering Contradiction:

Improvesignal-to-noise ratioVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent converts the waste heat generated by transmit amplifiers into useful electrical power through thermophotovoltaic cells. This transforms a harmful byproduct (waste heat) into a beneficial resource (electrical power) that can offset the power consumption of the antenna system, thereby enabling increased aperture size without proportional increases in net power consumption.

Inventive Principle:

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

Solution Approach 2:

The patent changes the operating temperature parameter of the amplifiers by using high-temperature solid-state amplifiers that can operate efficiently at elevated temperatures. This allows the system to tolerate and utilize higher temperature conditions, which are then converted to useful power through the thermophotovoltaic effect, fundamentally altering the thermal management approach from passive cooling to active power generation.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If aperture size is increased to improve radar performance, then signal-to-noise ratio is improved, but mass of cooling equipment increases

Engineering Contradiction:

Improvesignal-to-noise ratioVSAvoidmass of cooling equipment

Core Design Contradiction:

Measurement precisionVSWeight of moving object

Solution Approach 1:

Instead of treating waste heat as a problem requiring mass-intensive cooling equipment, the patent converts it into useful electrical power through thermophotovoltaic cells. This eliminates the need for traditional cooling systems and their associated mass, while simultaneously generating power to offset system consumption.

Inventive Principle:

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

Solution Approach 2:

The patent extracts useful electrical power from the waste heat generated by the transmit amplifiers using thermophotovoltaic cells. By extracting this energy resource from the thermal waste stream, the system eliminates the need for separate cooling equipment and its associated mass burden.

Inventive Principle:

Principle #2Taking out (Extraction)

3Device complexity

If receiver power per antenna element is kept constant as aperture increases, then system simplicity is maintained, but overall power consumption increases non-linearly

Engineering Contradiction:

Improvesystem simplicityVSAvoidoverall power consumption

Core Design Contradiction:

Device complexityVSUse of energy by moving object

Solution Approach 1:

The patent merges the waste heat management function with the power generation function by using thermophotovoltaic cells to convert waste heat into electrical power. This combined approach allows the system to maintain constant receiver power per element while the generated power offsets the increasing transmit power requirements, breaking the non-linear power consumption trend.

Inventive Principle:

Principle #5Merging (Combining)

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 approach enables a substantial and potentially indefinite increase in aperture size while reducing power consumption, significantly improving the radar signal-to-noise ratio without increasing mass, applicable to large array antennas on airships, ground, or in space.

Implementation Method 1

a heat harvester including a thermophotovoltaic (TPV) material configured to receive waste heat form the transmit module and convert the waste heat to electricity

Methodology Applied

Scientific EffectThermophotovoltaic effect: Photovoltaic Effect

Data Source

PatentUS8654019B2Power aperture linearization

Publication Date: 2014.02.18 LOCKHEED MARTIN CORP

AI summary

Antennas systems are disclosed providing for the use of heat harvesters such as thermophotovoltaic cell materials for converting waste heat from antenna transmitters into useful electricity. A further aspect of the present disclosure provides for transmitters that include high-temperature solid-state power amplifiers for operation at relatively high temperatures, reducing or eliminating the need for thermal heat spreaders or heat sinks. Quantum-effect thermophotovoltaic cells, including quantum-dot based thermophotovoltaic cells are described. Field-coupling is described to extract energy from a quantum-dot based TPV. Novel solar cells are also disclosed.