True-Time Delay Lens for Beam Collimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Frequency selective surfaces (FSS) face challenges in providing flexible frequency filtering and efficient electromagnetic wave manipulation due to their fixed structural features, which restrict their ability to effectively handle varying electromagnetic frequencies.
Innovation Solution
A lens structure composed of a multi-layered frequency selective surface with a 2-D grid of capacitive patches and dielectric sheets, forming time delay circuits to re-radiate spherical radio waves as planar waves, allowing for beam collimation and flexible frequency handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a frequency selective surface uses fixed structural features, then the structure can be simplified and manufactured easily, but the ability to handle varying electromagnetic frequencies is restricted
Solution Approach 1:
The FSS is divided into multiple layers with different functional characteristics. Each layer contains specific patch patterns (e.g., rectangular patches, triangular patches, circular patches) that can be independently designed for different frequency responses. This segmentation allows the overall structure to handle a broader frequency range while maintaining manufacturing simplicity for each individual layer.
Solution Approach 2:
The patent employs composite FSS structures combining multiple types of conductive patches (rectangular, triangular, circular) on different layers with specific ground patterns. These composite structures create multiple resonance frequencies and impedance characteristics, enabling the surface to effectively interact with varying electromagnetic frequencies while using standard manufacturing techniques for each component.
2Adaptability or versatility
If the FSS structure is made more complex to handle varying frequencies, then frequency filtering flexibility is improved, but the structural complexity and manufacturing difficulty increase
Solution Approach 1:
Instead of creating a single complex FSS structure, the patent segments the frequency filtering function across multiple layers, each with relatively simple patch patterns. This allows frequency filtering flexibility to be achieved through layer combination rather than within-layer complexity, reducing individual manufacturing difficulties.
Solution Approach 2:
The FSS layers are designed with universal characteristics that allow them to serve multiple functions: some layers provide primary frequency selection, others provide impedance matching, and certain patterns serve both as radiating elements and ground structures. This multi-functionality reduces the need for additional specialized components, thereby reducing overall structural complexity.
3Ease of manufacture
If standard impedance boundaries are used in FSS design, then the design process is simplified, but spatial coherence over varying frequencies cannot be achieved
Solution Approach 1:
The patent implements local impedance variations within the FSS structure by using different patch patterns and ground configurations in different regions and layers. For example, certain areas use dense patch patterns for high impedance while other areas use sparse patterns for low impedance. This local quality variation enables spatial coherence to be maintained across varying frequencies without requiring a complete redesign of the entire structure.
Solution Approach 2:
The design employs parameter variations in patch dimensions, spacing, and patterns across different layers to achieve frequency-independent spatial coherence. By carefully controlling parameters such as patch width, length, separation distance, and ground pattern geometry, the FSS maintains consistent electromagnetic performance across a broad frequency range while retaining relatively simple design procedures.
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 efficient beam collimation and flexible frequency filtering by re-radiating spherical radio waves as planar waves, ensuring spatial coherence over a desired frequency range, thereby enhancing the performance of transmitters and receivers.
Implementation Method 1
The first 2-D grid of capacitive patches is aligned with the second 2-D grid of capacitive patches to form a time delay circuit at each grid position of the aligned 2-D grids
Implementation Method 2
The electromagnetic wave feed element is configured to receive a signal, and in response, to radiate a spherical radio wave toward the first 2-D grid of capacitive patches. The time delay circuit at each grid position of the aligned 2-D grids is selected to re-radiate the spherical radio wave in the form of a second radio wave
Implementation Method 3
The first sheet layer includes a dielectric sheet and a second 2-D grid of capacitive patches. The dielectric sheet has a front surface and a back surface.
Data Source
AI summary
A lens is provided. The lens includes a first two-dimensional (2-D) grid of capacitive patches and a first sheet layer. The first sheet layer includes a dielectric sheet and a second 2-D grid of capacitive patches. The dielectric sheet has a front surface and a back surface. The first 2-D grid of capacitive patches is mounted directly on the back surface of the dielectric sheet, and the second 2-D grid of capacitive patches is mounted directly on the front surface of the dielectric sheet. The first 2-D grid of capacitive patches is aligned with the second 2-D grid of capacitive patches to form a time delay circuit at each grid position of the aligned 2-D grids.