RF Lens Photonic Crystal Apodizing Mask Side-Lobe Suppression
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Solution Overview
Problem
Radio frequency (RF) transmission systems face challenges in suppressing side-lobe energy, which is critical for reducing the detectability and vulnerability to jamming and eavesdropping.
Innovation Solution
A radio frequency lens with a photonic crystal structure, comprising a series of holes within a parent material, is designed to refract RF beams into a diffraction-limited profile, using impedance matching layers and an apodizing mask with a photonic crystal structure to create a continuous energy profile and control phase errors, thereby reducing side-lobe energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a dish antenna is used to transmit RF signals, then the beam can be reflected and transmitted, but side-lobe energy is substantially transmitted which increases detectability and vulnerability to jamming
Solution Approach 1:
The patent applies local quality by creating a non-uniform aperture illumination profile across the lens surface. The apodizing mask and photonic crystal structure vary the energy distribution from the center to the edges of the aperture, with reduced energy at the edges. This localized variation in energy distribution suppresses side-lobe formation while maintaining main beam integrity, directly addressing the harmful side-lobe energy transmission.
Solution Approach 2:
The patent changes the energy distribution parameter across the aperture by introducing continuous derivatives of the energy distribution function. The photonic crystal structure and apodizing mask modify the amplitude and phase parameters of the RF beam across different regions of the aperture, creating a smooth energy profile that eliminates abrupt transitions and reduces side-lobe energy.
2Weight of moving object
If a photonic crystal structure with holes is used to create the lens, then the lens becomes lightweight and structurally intact at rim portions, but manufacturing precision is required to maintain diffraction-limited wavefront qualities
Solution Approach 1:
The patent employs a photonic crystal structure consisting of a periodic array of holes within the lens material. This porous structure reduces the overall weight of the lens while maintaining its optical functionality. The holes are strategically positioned and sized to control the phase and amplitude of the RF beam, achieving diffraction-limited wavefront qualities despite the reduced material density.
Solution Approach 2:
The lens is constructed as a composite structure combining the photonic crystal material with an apodizing mask layer. This composite approach allows the lightweight photonic crystal structure to provide structural integrity and weight reduction, while the apodizing mask layer contributes the necessary energy distribution control. The combination achieves both weight reduction and precise beam control.
3Object-affected harmful factors
If impedance matching layers and apodizing mask are applied to control energy profile, then side-lobe energy is reduced, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into integrated components. The apodizing mask is combined with the photonic crystal structure, and impedance matching layers are integrated into the lens design. This merging reduces the number of separate components and simplifies the overall device architecture while maintaining the side-lobe suppression functionality. The combined structure achieves energy profile control without requiring separate, complex subsystems.
Solution Approach 2:
The photonic crystal structure serves multiple functions simultaneously: it provides mechanical support, creates the aperture illumination profile, controls phase distribution, and enables beam steering. The apodizing mask likewise performs multiple roles including energy distribution control and side-lobe suppression. This multi-functionality reduces device complexity by eliminating the need for separate components for each function.
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 lens achieves a substantial reduction in side-lobe energy, enabling tighter beam control, greater structural integrity, and simpler manufacturing, while maintaining lightweight construction, effectively reducing the detectability and jamming susceptibility of RF beams.
Implementation Method 1
The lens is constructed of a lightweight mechanical arrangement of two or more materials, where the materials are arranged to form a photonic crystal structure
Implementation Method 2
collimates an RF beam by refracting the beam into a beam profile that is diffraction-limited
Implementation Method 3
The photonic crystal structure of the present invention embodiments provides several advantages. In particular, the lens structure provides for precise control of the phase error across the aperture (or phase taper at the aperture) simply by changing the spacing and size of the hole patterns
Implementation Method 4
an absorptive or apodizing mask is applied to the lens to create a specific energy profile across the lens
Implementation Method 5
The lens includes impedance matching layers
Data Source
AI summary
An RF lens according to the present invention embodiments collimates an RF beam by refracting the beam into a beam profile that is diffraction-limited. The lens is constructed of a lightweight mechanical arrangement of two or more materials, where the materials are arranged to form a photonic crystal structure (e.g., a series of holes defined within a parent material). The lens includes impedance matching layers, while an absorptive or apodizing mask is applied to the lens to create a specific energy profile across the lens. The impedance matching layers and apodizing mask similarly include a photonic crystal structure. The energy profile function across the lens aperture is continuous, while the derivatives of the energy distribution function are similarly continuous. This lens arrangement produces a substantial reduction in the amount of energy that is transmitted in the side-lobes of an RF system.