Tunable Aperture Using Photoconductive Material for Multi-Spectrum Antennas
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Solution Overview
Problem
Photo-conductive antennas activated by laser pulses or continuous wave laser light are limited in their ability to accommodate different frequencies and are non-conductive when the laser source is turned off, making them inflexible for multi-spectrum operations and cumbersome due to the use of optical fibers.
Innovation Solution
A tunable RF antenna system using a photonic integrated circuit (PIC) with a photoconductive material that becomes conductive upon laser illumination, allowing frequency adjustment across a wide bandwidth (0.5 GHz to 18 GHz) while maintaining an integrated infrared channel, utilizing a focal plane array for infrared detection and a metallic center section for transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If photo-conductive antenna elements are used with laser activation, then the antenna can be non-conductive when laser is off providing security advantage, but the antenna cannot transmit or receive electromagnetic waves in non-conductive state
Solution Approach 1:
The patent applies dynamics by making the antenna elements switchable between conductive and non-conductive states through laser activation. The photo-conductive material allows the antenna to dynamically change its electrical properties based on laser illumination, enabling it to be non-conductive when laser is off (reducing radar cross section) and conductive when laser is on (enabling electromagnetic wave transmission).
Solution Approach 2:
The patent changes the electrical conductivity parameter of the antenna elements by using photo-conductive material that transitions between conductive and non-conductive states. This parameter change is controlled by laser activation, allowing the system to adapt between different operational modes (transmit/receive vs. stealth) and accommodate different frequencies of operation.
2Reliability
If optical fibers are used to feed light to photo-conductive antennas, then the antenna can be activated, but the system becomes cumbersome
Solution Approach 1:
The patent extracts the light source from external optical fibers and integrates it directly into the antenna structure. By incorporating laser diodes and waveguides within the antenna elements themselves, the system eliminates the need for external optical fiber arrays, thereby reducing device complexity while maintaining reliable antenna activation.
Solution Approach 2:
The patent nests the light source components (laser diodes and waveguides) within the antenna structure. The optical components are integrated into the antenna elements, with waveguides embedded in the substrate leading to photo-conductive regions, creating a compact nested structure that combines transmission and illumination functions.
3Adaptability or versatility
If antenna elements are made conductive for RF operation, then electromagnetic waves can be transmitted and received, but the antenna cannot accommodate different frequencies of operation
Solution Approach 1:
The patent achieves multi-functionality by integrating both RF antenna elements and IR sensors within the same aperture structure. The photo-conductive material serves dual purposes: as RF antenna elements when conductive and as an optical platform for IR sensors. This universal structure can operate across multiple frequency bands (RF and IR) without requiring separate dedicated structures, thereby reducing overall device complexity while enhancing adaptability.
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
Enables simultaneous operation in multiple spectrums with a compact size, weight, and power (SWAP) space, providing flexibility in frequency tuning and reduced radar cross-section, suitable for various applications including radars, satellites, and electronic intelligence systems.
Implementation Method 1
an antenna aperture comprising: an RF antenna having first and second portions, wherein the first portion comprises a photoconductor material having a conductive state and a non-conductive state
Implementation Method 2
the PIC comprises a laser to selectively illuminate the first portion of the RF antenna and select the conductive state
Implementation Method 3
an IR sensor to detect IR energy
Data Source
AI summary
Methods and apparatus for a tunable dual spectrum antenna aperture including a RF antenna having first and second portions, wherein the first portion comprises a photoconductor material having a conductive state and a non-conductive state, and an IR sensor to detect IR energy. The state of the first portion determines a size of the RF antenna.