2D Electronic Steering Antenna Using Tunable Impedance Surface
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing artificially steerable impedance surface antennas (AISAs) are costly and complex, limiting their ability to provide two-dimensional electronic steering, which is necessary for various applications, and often require mechanical steering or vias that reduce operation bandwidth.
Innovation Solution
A low-cost, 2D electronically steerable artificial impedance surface antenna design that uses a tunable artificial impedance surface with a periodic array of metallic strips and varactors, allowing for independent control of theta and phi direction steering through phase shifting and impedance modulation, respectively, without the need for complex voltage control networks or mechanical steering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If phased array antennas are used to provide two-dimensional electronic steering, then steering capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent segments the steering control into two independent dimensions: one dimension uses a phased array feed network for electronic beam steering, while the other dimension uses mechanical rotation of the entire antenna assembly. This segmentation allows 2D steering capability without requiring a fully complex 2D electronically steered array, reducing overall system complexity and cost.
2Adaptability or versatility
If mechanically steering a 1D electronically steered antenna is used to provide two-dimensional steering, then steering capability is improved, but reliability decreases due to mechanical components
Solution Approach 1:
The patent merges a 1D electronically steered AISA with a phased array feed network in a hybrid configuration. The phased array provides electronic steering in one dimension while the AISA provides coverage in the orthogonal dimension through its inherent radiation pattern, creating a combined system that achieves 2D steering with reduced mechanical components and improved reliability.
3Ease of operation
If vias are used to provide voltage control to varactors in AISAs, then impedance control is improved, but operation bandwidth is reduced
Solution Approach 1:
The patent extracts the voltage control function from traditional via-based implementations and implements it through a phased array feed network that provides electronic control without requiring penetrating vias through the AISA structure. This extraction maintains impedance control capability while preserving the full operational bandwidth of the AISA by eliminating the bandwidth-limiting via structures.
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 cost-effective, two-dimensional electronic steering of the antenna's primary gain lobe, expanding the operational bandwidth and reducing the complexity of the antenna system while maintaining efficient beam steering capabilities.
Implementation Method 1
a second set of voltages is applied to a second set of varactors to modulate an impedance of the artificial impedance surface in the second dimension
Implementation Method 2
Artificial impedance surface antennas (AISAS) are realized by launching a surface wave across an artificial impedance surface (AIS)
Implementation Method 3
whose impedance is spatially modulated across the AIS according a function, that matches the phase fronts between the surface wave on the AIS and the desired far-field radiation pattern
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A steerable artificial impedance surface antenna steerable in phi and theta angles including a dielectric substrate, a plurality of metallic strips on a first surface of the dielectric substrate, the metallic strips spaced apart across a length of the dielectric substrate and each metallic strip extending along a width of the dielectric substrate, and surface wave feeds spaced apart along the width of the dielectric substrate near an edge of the dielectric substrate, wherein the dielectric substrate is substantially in an X-Y plane defined by an X axis and a Y axis, wherein the phi angle is an angle in the X-Y plane relative to the X axis, and wherein the theta angle is an angle relative to a Z axis orthogonal to the X-Y plane.