Reflectarray Patches With Comb-Shaped Capacitors For Phase Control
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Solution Overview
Problem
Conventional reflectarrays face challenges in directing radio waves to desired directions with small incident angles due to limited phase shift range and radiation losses, particularly when using stubs or varying patch sizes, which also affect radiation patterns.
Innovation Solution
A reflectarray design featuring patches with a comb-shaped fringe capacitor structure, where the length and width of fingers can be varied to adjust the load impedance and phase shift without changing the size of the array elements, achieving a wider phase range of the reflection coefficient.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the size of array elements is varied to produce phase shift, then the phase shift is achieved, but the radiation characteristics are affected and element sizes become inconsistent
Solution Approach 1:
The array element is segmented into multiple patches arranged in a grid pattern. By controlling the number of patches activated in each element rather than varying the physical size of elements, the phase shift is achieved while maintaining consistent element boundaries and radiation characteristics.
Solution Approach 2:
Instead of changing the physical dimensions of array elements, the invention changes the electrical parameters by varying the number of patches excited in each element. This parameter change approach achieves phase shift control without affecting the radiation characteristics determined by element geometry.
2Ease of operation
If stubs are used to achieve phase shift, then the phase shift is produced, but loss and unnecessary radiation occur
Solution Approach 1:
The invention extracts and removes the stub component from the array element design. By eliminating the stub structure, the source of loss and unnecessary radiation is removed, while phase shift functionality is maintained through the patch number control mechanism.
Solution Approach 2:
The invention converts the potential harm of stub-induced loss and radiation into a benefit by completely eliminating the stub structure. The phase shift function is achieved through a cleaner approach using patch excitation control, transforming the problematic stub-based method into a superior patch-based method.
3Ease of operation
If the reflector is inclined toward the ground to increase incident and reflection angles, then the beam direction is improved, but safety concerns arise due to placement on high places
Solution Approach 1:
The invention changes the operational parameters of the reflectarray by controlling the phase of reflected waves from each element. This allows electronic beam steering to achieve desired direction control without physically inclining the reflector structure, thereby eliminating safety risks associated with groundward inclination at high placements.
4Device complexity
If conventional reflectarray methods are used, then the structure is simple, but the phase range of reflection coefficient is limited to less than 360 degrees
Solution Approach 1:
The array element is divided into multiple patches that can be independently controlled. By varying the number of patches excited in each element, the invention achieves a reflection coefficient phase range exceeding 360 degrees while maintaining the overall simplicity of the reflectarray structure.
Solution Approach 2:
The patch-based control mechanism provides multi-functionality, enabling the reflectarray to achieve wide phase range (over 360 degrees) while maintaining structural simplicity. The same patch configuration can serve multiple phase requirements, enhancing adaptability without increasing complexity.
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 design allows for a phase shift range of over 1000 degrees, enabling effective beam direction control and reducing radiation losses, while maintaining consistent array element sizes to prevent characteristic deterioration.
Implementation Method 1
The reflectarray can be designed by arranging phase shifts of reflected waves such that a beam is directed to a desired direction
Implementation Method 2
A reflectarray design featuring patches with a comb-shaped fringe capacitor structure, where the length and width of fingers can be varied to adjust the load impedance and phase shift
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A reflectarray, including: a substrate; and a plurality of patches formed on each of areas into which a principal surface of the substrate is divided, wherein the plurality of patches are formed by including a gap.