Scanning Antenna Beam Steering via Evanescent Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current scanning antennas face limitations in scanning accuracy and controllability, particularly in a single selected plane, such as the horizontal plane, which hinders their performance in applications like radar and communication systems.
Innovation Solution
The design incorporates a waveguide assembly with parallel conductive plates surrounding a transmission line, allowing evanescent coupling and confining the electromagnetic signal to a specific plane, and utilizing a selectively variable diffraction grating or edge geometry to control beam direction, with polarization ensuring the electric field is parallel to the plates, thereby enhancing beam-steering precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If evanescent coupling is used between transmission line and antenna element, then beam-steering capability is achieved, but signal leakage between plates and antenna element occurs
Solution Approach 1:
The patent introduces waveguide plates as an intermediary structure between the transmission line and antenna element. These plates create a controlled electromagnetic environment that mediates the coupling process, allowing beam-steering functionality while preventing signal leakage through proper geometric configuration and polarization control.
Solution Approach 2:
The patent utilizes polarization control as a parameter change mechanism. By controlling the polarization state of the electromagnetic signal and ensuring the electric field component is parallel to the plates, the system achieves both beam-steering capability and signal containment, transforming the coupling geometry to eliminate leakage.
2Adaptability or versatility
If coupling geometry is made selectively variable for beam-steering, then scanning functionality is achieved, but scanning accuracy and controllability in a single plane deteriorates
Solution Approach 1:
The patent segments the three-dimensional space by introducing parallel waveguide plates that confine the electromagnetic beam to a specific plane. This segmentation approach divides the scanning function into planar scanning within the confined space, thereby achieving both scanning versatility and improved scanning accuracy within the selected plane.
Solution Approach 2:
The patent uses the waveguide plates to add a dimensional constraint, transitioning from three-dimensional beam propagation to two-dimensional planar confinement. This dimensionality change enables precise control and accuracy within the confined plane while maintaining the overall scanning functionality.
3Measurement precision
If waveguide plates are added to confine beam to plane, then scanning accuracy is improved, but device complexity increases
Solution Approach 1:
The patent employs thin waveguide plates as flexible structural elements to confine the electromagnetic beam. These plates provide the necessary geometric constraint for improved scanning accuracy while maintaining a relatively simple and elegant structure that does not significantly increase overall device 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 configuration significantly improves scanning accuracy and controllability by confining the electromagnetic beam to a single plane, reducing signal leakage and allowing precise beam-shaping and steering within the desired plane, enhancing the antenna's functionality in communication and radar applications.
Implementation Method 1
the transmission line is located adjacent the evanescent coupling portion so as to permit evanescent coupling of an electromagnetic signal between the transmission line and the antenna element
Implementation Method 2
first and second substantially parallel conductive waveguide plates disposed on opposite sides of the transmission line... whereby the electromagnetic signal propagated as a result of the evanescent coupling forms a beam that is confined to the space defined between the plates
Implementation Method 3
The coupling portion may be a portion of the antenna element formed as controllably variable diffraction grating
Implementation Method 4
the shape and direction of the transmitted or received beam are determined by the coupling geometry of the coupling portion
Data Source
Figure 1
Figure 2~4
Figure 5~7
AI summary
A scanning antenna with an antenna element having an evanescent coupling portion includes a waveguide assembly including a transmission line, adjacent the coupling portion, through which an electromagnetic signal is transmitted, permitting evanescent coupling of the signal between the transmission line and the antenna element. First and second conductive waveguide plates, on opposite sides of the transmission line, define planes that are substantially parallel to the axis of the transmission line, each plate extending distally from a proximal end adjacent the antenna element, whereby the propagated signal forms a beam that is confined to the space between the plates and thus limited to a plane that is parallel to the planes defined by the plates. The signal coupled between the transmission line and the antenna element is preferably polarized so that its electric field component is in a plane parallel to the planes defined by the plates.