Flexible Leaky-Wave Antenna Array Asymmetry for Broadside Gain
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Leaky-Wave Antennas (LWAs) suffer from gain degradation at the broadside due to open stopband (OSB) conditions, which hinders seamless transitions from backward to forward radiation.
Innovation Solution
The implementation of a conformal and flexible bent-stub folded combline LWA structure on a thin PET substrate with optimized longitudinal and transverse asymmetries, incorporating a folded feed-line and bent stub pairs to suppress OSB, ensuring consistent antenna gain across the radiation bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional LWA structure is used, then broadside radiation is achieved, but gain degradation occurs due to open stopband conditions
Solution Approach 1:
The patent applies asymmetry by introducing longitudinal asymmetry through different stub lengths (l1 ≠ l2) and transverse asymmetry through offset positioning of stubs relative to the feedline. This asymmetric configuration transforms the open stopband condition into a closed stopband, enabling seamless radiation pattern transitions and consistent gain across the bandwidth while maintaining broadside radiation capability.
2Adaptability or versatility
If multiple LWAs are placed in array configuration, then angular coverage is increased, but mutual coupling between antennas increases
Solution Approach 1:
The asymmetric stub configuration (different lengths l1 and l2, offset positioning) reduces mutual coupling between adjacent antennas in the array. This asymmetry disrupts the coupling paths between elements, allowing the array to achieve enhanced angular coverage through frequency scanning while maintaining low mutual coupling levels.
3Ease of operation
If frequency scanning is implemented, then beam direction is controlled, but gain degradation occurs at broadside frequency
Solution Approach 1:
The asymmetric stub design with different lengths and offset positioning enables frequency scanning for beam steering while simultaneously closing the stopband at broadside frequency. This resolves the gain degradation issue by transforming the OSB condition into a CSB condition, allowing seamless transitions and consistent gain across the entire frequency range including broadside.
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 enhances radiation performance by reducing mutual coupling and increasing angular coverage, achieving a seamless transition from backward to forward radiation while maintaining high gain and broadside frequency scanning.
Implementation Method 1
A Leaky-Wave Antennas (LWA) is a beam-forming antenna that uses a traveling wave on a guiding structure as main radiating mechanism. The antenna can radiate from nearly resonant stubs to ensure a small leakage constant and a high directivity. For example, a guided wave leaks out of the guiding structure as the guided wave propagates.
Implementation Method 2
The antenna can radiate from nearly resonant stubs to ensure a small leakage constant and a high directivity.
Data Source
AI summary
Methods and systems are disclosed for an antenna system capable of optimal broadside radiation. In certain embodiments, a system may include a flexible and thin polyethylene terephthalate (PET) substrate stack having a predetermined length. The system may include a printed circuit board (PCB) fabrication of one or more Leaky-Wave Antenna (LWA) structures on the PET substrate stack. The one or more LWA structures have a bent-stub folded LWA configuration have longitudinal asymmetry and transverse asymmetry for a broadside frequency. The bent-stub folded LWA configuration comprises a plurality of conductively unit cells having a unit cell period. Each unit cell of the plurality of conductively unit cells has a folded main feed-line and a bent stub pair with two angularly bent radiating stubs. Embodiments are structured to increase radiation per-unit length and suppress open stopband (OSB).