Frequency Diverse Phased-Array Antenna With 3D Ground Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional phased-array antennas face challenges in achieving compact and economical frequency diversity with minimized grating lobes, especially when operating at multiple frequencies, due to limited aperture size and difficulty in obtaining good isolation between antenna elements separated by sub-wavelength distances.
Innovation Solution
A frequency diverse phased-array antenna design utilizing a multi-layer substrate with a checkerboard of antenna elements and three-dimensional ground planes and walls, where conductive vias or metal mesh provide signal isolation and optimize operation across multiple frequencies, allowing for simultaneous operation in two bands with orthogonal polarization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If antenna elements are placed close together to reduce aperture size, then device compactness is improved, but signal isolation between elements deteriorates
Solution Approach 1:
The patent transitions from a two-dimensional planar array to a three-dimensional volumetric array by stacking multiple layers of antenna elements separated by dielectric substrates. This vertical dimensionality change allows elements to be closely spaced in the horizontal plane while maintaining isolation through vertical separation, thus reducing aperture size without compromising signal isolation.
Solution Approach 2:
Dielectric substrates are introduced as intermediary materials between antenna elements to provide electrical isolation and control impedance. These substrates act as mediators that prevent direct signal coupling between closely spaced elements while allowing the elements to be positioned in a compact volumetric arrangement.
2Reliability
If substrate thickness is increased to optimize antenna performance at a given frequency, then antenna gain is improved, but device compactness deteriorates
Solution Approach 1:
Instead of increasing substrate thickness in a single layer, the patent distributes the required electrical path length across multiple thin layers stacked vertically. This allows achieving the necessary electrical performance through vertical stacking of thin substrates rather than using a single thick substrate, maintaining compactness while optimizing antenna performance.
Solution Approach 2:
The substrate structure is segmented into multiple thin dielectric layers, each contributing to the overall electrical performance. This segmentation allows the total effective electrical thickness to be achieved through stacking, providing the necessary performance without requiring any single layer to be excessively thick.
3Productivity
If element spacing is reduced to fit more elements in the array, then array density is improved, but grating lobe formation increases
Solution Approach 1:
The patent arranges antenna elements in a three-dimensional volumetric grid rather than a two-dimensional planar grid. This vertical dimensionality allows dense horizontal spacing without the grating lobe issues that plague planar arrays, as the vertical separation breaks the periodicity that causes grating lobes in conventional arrays.
Solution Approach 2:
The patent uses composite dielectric-substrate structures with specific permittivity values to control the effective wavelength and spacing relationships. By carefully selecting dielectric materials with appropriate electrical properties, the array can achieve dense element spacing while the dielectric properties help suppress grating lobe formation through impedance control and wavelength scaling.
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 enables efficient operation at multiple frequencies with reduced grating lobes and improved signal discrimination, supporting dual polarization and allowing for the placement of separate antennas in the same aperture with minimal separation, enhancing beam direction and polarization control.
Implementation Method 1
Phased-array elements are isolated by a conductive wall in a multi-layer substrate
Implementation Method 2
A frequency diverse phased-array antenna operates simultaneously in two bands. A checkerboard of antenna elements for a first wavelength is offset with a second checkerboard of second antenna elements
Data Source
AI summary
A frequency diverse phased-array antenna operates simultaneously in two bands. A checkerboard of antenna elements for a first wavelength is offset with a second checkerboard of second antenna elements. Within the substrate is a three dimensional checkerboard of ground planes and ground walls which provide signal isolation between the bands. Multiple ground planes optimize operation at the several frequencies. Phased-array elements are isolated by a conductive wall in a multi-layer substrate. Orthogonal polarization of antenna patches further improve signal discrimination. Below the surface layer, another conductive wall isolates each quadrature hybrid. The conductive wall can be realized by metal vias or metal mesh infused through a dielectric and surrounding a raised ground plane to isolate electrical fields at each frequency. A conductive wall also provides quadrature hybrid isolation.