Low-Sidelobe Plate Array Antenna Design
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Solution Overview
Problem
Existing waveguide slot array antennas face challenges with high sidelobe levels, narrow frequency bandwidth, complex assembly structures, and increased costs due to multiple radiation layers and polarization layers, which hinder their application in modern radar and communication systems requiring low sidelobes and wide frequency coverage.
Innovation Solution
A low-sidelobe plate array antenna design featuring a radiation layer and a feed layer with a superimposed structure, where the radiation layer consists of 4*n2 TE10 mode signals and radiation units arranged in a specific configuration to optimize energy distribution and reduce sidelobes, while maintaining a compact and cost-effective structure suitable for mass production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional waveguide slot array antennas use power distribution control to reduce sidelobe, then sidelobe level is reduced, but main lobe becomes wider and gain decreases
Solution Approach 1:
The patent introduces a polarization layer that operates in a different dimensional space (polarization domain) rather than manipulating power distribution in the spatial domain. This polarization layer transforms the electric field polarization direction to achieve sidelobe reduction without affecting the main lobe width or gain, thereby resolving the contradiction between sidelobe level and gain.
Solution Approach 2:
The polarization layer acts as an intermediary component between the radiation layer and free space. It modifies the polarization state of radiated waves to suppress sidelobes while leaving the main beam characteristics unchanged, thus mediating between the conflicting requirements of low sidelobe and high gain.
2Reliability
If waveguide slot standing wave array antennas are designed for narrow bandwidth, then resonance performance is optimized, but frequency band is limited
Solution Approach 1:
The patent employs a traveling wave mechanism instead of a static resonance structure. The traveling wave allows the antenna to operate dynamically across a wide frequency range by continuously propagating energy along the waveguide, eliminating the narrow bandwidth limitation of resonance-based standing wave structures while maintaining reliable performance.
Solution Approach 2:
The invention changes the operating parameter from resonance frequency (fixed) to traveling wave propagation (variable). This parameter change enables the antenna to adapt to different frequencies within a wide bandwidth while maintaining consistent performance characteristics, resolving the contradiction between resonance optimization and bandwidth expansion.
3Object-generated harmful factors
If multiple radiation layers and polarization layers are added to reduce sidelobe, then sidelobe level is reduced, but device complexity and cost increase
Solution Approach 1:
The patent combines the polarization function with the radiation function in a single integrated polarization layer, rather than using separate radiation layers and polarization layers. This merging reduces structural complexity and assembly difficulty while achieving the same sidelobe reduction effect, thereby resolving the contradiction between sidelobe performance and device complexity.
4Adaptability or versatility
If waveguide slot array antennas use traveling wave structure, then bandwidth is expanded, but beam direction varies with frequency
Solution Approach 1:
The polarization layer serves as an intermediary that compensates for the frequency-dependent beam direction variation inherent in traveling wave structures. By adjusting the polarization state, it stabilizes the beam direction across different frequencies, thus resolving the contradiction between bandwidth expansion and beam direction consistency.
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 design achieves a low sidelobe level, wide frequency bandwidth, and high efficiency with simplified assembly, reducing cross-polarization and enhancing gain and aperture efficiency, making it suitable for mass production and modern electronic applications.
Implementation Method 1
part of the current across the surface of the inner wall of the waveguide bypasses the slots, the other part of the current flows across the slots in the original direction in a form of displacement current, and radiation is realized by power lines at the openings of the slots
Implementation Method 2
radiation is realized by power lines at the openings of the slots
Implementation Method 3
a polarization layer is arranged on the radiation layer to reduce the sidelobe; the polarization layer can change the polarization direction of an electric field of the radiation layer
Data Source
AI summary
A low-sidelobe plate array antenna includes a radiation layer and a feed layer. The radiation layer is superimposed on the feed layer and includes a first plate and a radiation array disposed on the first plate. The radiation array is formed by n2 radiation units which are distributed in 2(k-1) rows and 2(k-1) columns. Each radiation unit in the radiation layer is constituted by two first radiation assemblies and two second radiation assemblies. Each first radiation assembly comprises a first rectangular bar, a first rectangular cavity, a second rectangular cavity and a third rectangular cavity. The first rectangular cavity, the second rectangular cavity and the third rectangular cavity in the first radiation assembly are stacked in presence of an azimuth deviation to form a three-layer coupled structure, and the first rectangular bar located in the first rectangular cavity can better restrain cross polarization and reduce the sidelobe.