Reconfigurable Conical Beam Antenna with Ferroelectric Substrate
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Solution Overview
Problem
Conventional cross-dipole quadrifilar helix antennas have high profile characteristics, making them unsuitable for mobile terminals, and their radiation pattern performance degrades when the elevation angle changes, affecting link characteristics in mobile wireless communication systems.
Innovation Solution
A reconfigurable high-order mode conical beam antenna device with a micro-strip radiator, multiple feeding points, and a mode reconfigurable switching unit, allowing for control of antenna beam patterns through voltage-dependent permittivity in a ferro-electric substrate, providing high gain in the elevation direction and non-directional circular polarization in the azimuth direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a cross-dipole quadrifilar helix antenna is used to achieve non-directional circular polarization characteristics in the azimuth direction, then circular polarization characteristics are improved, but the profile height increases making it unsuitable for mobile terminals
Solution Approach 1:
The antenna is divided into multiple feeding points (at least three) positioned at different azimuth angles, with each feeding point independently controlled through switching units. This segmentation allows the antenna to achieve non-directional circular polarization characteristics without requiring the high profile structure of conventional quadrifilar helix antennas, thereby resolving the contradiction between polarization performance and compact size.
Solution Approach 2:
The antenna employs a reconfigurable feeding mechanism where the feeding point is dynamically switched among multiple positions based on the desired beam direction. This dynamic switching capability enables the antenna to adapt its radiation pattern while maintaining a low profile structure suitable for mobile terminals, resolving the contradiction between structural compactness and polarization performance.
2Adaptability or versatility
If the elevation angle changes due to mobile terminal movement on roads or latitude changes, then the antenna must maintain radiation pattern performance, but conventional antennas experience degradation in radiation pattern performance
Solution Approach 1:
The antenna system dynamically adjusts the feeding point selection based on the desired beam direction and elevation angle requirements. By switching between different feeding points positioned at various azimuth angles, the antenna maintains optimal radiation pattern performance across changing elevation angles, thereby resolving the contradiction between elevation angle adaptability and radiation pattern reliability.
Solution Approach 2:
The antenna changes its operational parameters by selecting different feeding points to excite different high-order modes, which alters the radiation pattern characteristics. This parameter change capability enables the antenna to maintain consistent performance across varying elevation angles, resolving the contradiction between adaptability and reliability.
3Adaptability or versatility
If multiple feeding points are used to enable beam pattern reconfiguration, then elevation angle control capability is improved, but the device complexity increases
Solution Approach 1:
The antenna feeds system is segmented into multiple independent feeding points, each capable of being independently activated through switching units. This segmentation enables flexible beam pattern reconfiguration for elevation angle control while keeping each individual feeding point simple, thereby resolving the contradiction between adaptability and 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
The solution enables improved radiation pattern symmetry and cross-polarization characteristics, allowing for elevation angle adjustments via electrical control, and facilitates a low-profile, cost-effective mobile satellite terminal antenna.
Implementation Method 1
the micro-strip radiator is formed on a first dielectric substrate whose relative permittivity value is changed depending on a voltage applied thereto. the first dielectric substrate is made of a ferro-electric material whose permittivity is changed depending on the applied voltage.
Implementation Method 2
A reconfigurable high-order mode conical beam antenna device with a micro-strip radiator, multiple feeding points, and a mode reconfigurable switching unit, allowing for control of antenna beam patterns through voltage-dependent permittivity in a ferro-electric substrate
Data Source
AI summary
An antenna device for generating a reconfigurable high-order mode conical beam, includes a micro-strip radiator having multiple feeding points, wherein one of the feeding points is a fixed feeding point, and a feeding unit for providing two signals having a same amplitude and a preset phase difference, wherein one of the two signals is fed through the fixed feeding point and the other is fed through any one of remaining feeding points. A mode reconfigurable switching unit, connected to the feeding unit, performs a switching operation to select any one of the remaining feeding points so that the other signal is feed through the selected feeding point in accordance with mode control data.