Switchable Lens Antenna with Frequency Selective Structure
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Solution Overview
Problem
Current lens-based phased array antennas face directivity losses at steering angles near the normal direction and have limited steering angle ranges, which restrict their operational effectiveness in wireless communications.
Innovation Solution
A switchable lens antenna with a parallel-plate waveguide structure and frequency selective elements that can operate in two modes: disconnecting or connecting frequency selective elements based on the steering angle to minimize losses and enhance steering angle ranges, using a controller to manage the operational mode and introduce phase variance to the RF wave.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If lens-based phased array antennas are used to achieve wider steering angle ranges, then the steering angle range is improved, but directivity losses occur at steering angles near the normal direction
Solution Approach 1:
The patent implements dynamic switching between two operational modes using controllable switches. The first mode operates without frequency selective elements for wide steering angles, while the second mode activates frequency selective elements to correct directivity losses at small steering angles. This dynamic reconfiguration allows the antenna to adapt its characteristics based on the required steering angle, resolving the contradiction between wide steering range and maintained directivity.
Solution Approach 2:
The patent changes the electrical parameters of the antenna system by selectively connecting or disconnecting frequency selective elements. By modifying the effective electrical length and impedance characteristics through the switches, the antenna can optimize its performance for different steering angle ranges, eliminating directivity losses when needed while maintaining wide steering capability when required.
2Loss of energy
If frequency selective elements are connected to correct directivity losses at small steering angles, then directivity is improved, but the steering angle range is limited
Solution Approach 1:
The controllable switches enable dynamic reconfiguration of the antenna system. When small steering angles are required, the frequency selective elements are connected to correct directivity losses. When wide steering angles are needed, the switches disconnect these elements, allowing the full steering angle range to be utilized without performance degradation from the frequency selective structure.
3Adaptability or versatility
If a switchable configuration is implemented to resolve the contradiction between directivity and steering angle range, then operational flexibility is improved, but device complexity increases
Solution Approach 1:
The patent divides the antenna structure into distinct segments: the parallel-plate waveguide structure, the frequency selective elements, and the controllable switches. This segmentation allows each component to perform its specific function independently, making the overall system more manageable despite the added complexity. The modular approach enables precise control over when frequency selective elements are activated.
Solution Approach 2:
The frequency selective elements serve multiple functions: they correct directivity losses at small steering angles and can be selectively activated or deactivated based on operational requirements. The controllable switches provide universal control capability, allowing the same hardware structure to adapt to different operational modes, thereby justifying the added complexity through enhanced functionality.
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 switchable lens antenna reduces directivity losses at steering angles near the normal direction and provides wider steering angle ranges, improving angular coverage and polarization agility while maintaining directivity, thus enhancing wireless communication capabilities.
Implementation Method 1
Each frequency selective element comprises a stub, configured to introduce a phase variance to the RF wave when the stub is electrically connected to the parallel-plate waveguide structure
Implementation Method 2
The switchable element is configured to selectively electrically disconnect the stub from the parallel-plate waveguide structure when the antenna is in a first operational mode and to electrically connect the stub to the parallel-plate waveguide structure when the antenna is in a second operational mode
Implementation Method 3
excitation ports operable to radiate the RF wave into the parallel-plate waveguide structure
Data Source
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AI summary
The disclosed structures and methods are directed to antenna systems configured to transmit and receive a wireless signal in and from different directions. A switchable lens antenna has excitation ports radiating radio-frequency (RF) wave into a parallel-plate waveguide structure, and a frequency selective structure (FSS). The antenna presented herein is configured to operate in two modes depending on a steering angle of the RF wave propagating in the parallel-plate waveguide structure. When the steering angle is about or less than a threshold steering angle, FSS is OFF due to its stubs being electrically disconnected from the parallel-plate waveguide structure. When the steering angle is higher than the threshold, FSS is ON with stubs being electrically connected to the parallel-plate waveguide structure. When ON, FSS provides phase variance to the RF wave propagating in the parallel-plate waveguide structure and increases steering angle of the RF wave.