Planar Antenna Multi-Polarization Quarter-Perimeter Feed
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Solution Overview
Problem
Current antennas lack versatility in polarization capabilities, particularly for achieving linear, circular, dual linear, and dual circular polarizations in a compact and efficient planar form, limiting their application in various communication systems.
Innovation Solution
A planar, electrically conductive patch antenna with a geometric shape and spaced signal feedpoints along its perimeter, separated by a quarter of the perimeter, which allows for versatile polarization capabilities through phase input-driven feed structures, eliminating the need for a ground plane and enabling enhanced gain in a smaller size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional dipole turnstile antennas are used to achieve dual linear polarization, then polarization versatility is provided, but the antenna occupies larger area with reduced gain
Solution Approach 1:
The antenna is segmented into four distinct arms (first arm, second arm, third arm, fourth arm) arranged in a planar configuration, where each arm contributes to different polarization components. This segmentation allows the antenna to achieve dual linear and dual circular polarization capabilities while maintaining a compact planar structure, resolving the contradiction between polarization versatility and area occupation.
Solution Approach 2:
The invention transitions from traditional three-dimensional dipole structures to a two-dimensional planar configuration. The four arms are arranged in a plane with specific geometric relationships (90-degree angles between adjacent arms), enabling the antenna to achieve versatile polarization characteristics in a reduced area footprint by utilizing spatial arrangement within a plane rather than extending in three dimensions.
2Power
If full wave loop antennas are used to increase gain, then gain is improved to 3.6 dBi, but the antenna structure becomes more complex and less versatile in polarization
Solution Approach 1:
The four-arm planar antenna structure serves multiple functions simultaneously: it provides dual linear polarization, dual circular polarization, and can be configured for single polarization modes. The same physical structure (four arms in a plane) enables all these polarization modes by adjusting feed configurations and phase relationships, eliminating the need for separate antenna structures for different polarization requirements and thereby reducing overall system complexity.
Solution Approach 2:
The antenna employs asymmetric feeding configurations and phase relationships among the four arms to achieve different polarization modes. By introducing 90-degree phase differences between specific arm pairs and utilizing asymmetric current distributions, the antenna generates circular polarization, while symmetric feeding produces linear polarization. This asymmetric control mechanism enables polarization versatility without requiring complex structural modifications.
3Area of stationary object
If compact antenna structures are used to reduce size, then area is reduced, but gain and bandwidth performance deteriorate
Solution Approach 1:
The antenna incorporates curved or rounded transitions at the joints between arms and at the feed points, replacing sharp angular connections. This curvature optimizes current distribution and reduces impedance discontinuities, improving radiation efficiency and gain. The curved geometry also helps in achieving broader bandwidth by reducing resonant effects associated with sharp corners, thereby maintaining performance in a compact planar structure.
4Reliability
If ground plane is included in traditional antenna designs, then radiation pattern is improved, but the antenna becomes less suitable for conformal mounting and increases overall size
Solution Approach 1:
The invention extracts and eliminates the ground plane component from the antenna structure, relying instead on the four-arm planar configuration and strategic feed point placements to achieve the desired radiation characteristics. The four arms themselves, when properly fed with appropriate phase and amplitude relationships, provide the necessary current distributions to generate stable radiation patterns without requiring a ground plane, thereby enabling conformal mounting on various surfaces and reducing overall antenna size.
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 provides a compact, inexpensive antenna with enhanced gain and versatile polarization capabilities, suitable for various communication applications, including personal and satellite communications, with improved gain and bandwidth compared to traditional antennas.
Implementation Method 1
A feed structure may be coupled to the signal feedpoints to drive the planar, electrically conductive, patch antenna element with a phase input to provide at least one of linear, circular, dual linear and dual circular polarizations
Implementation Method 2
A pair of spaced apart signal feedpoints along the outer perimeter of the antenna element and separated by a distance of one quarter of the outer perimeter to impart a traveling wave current distribution
Data Source
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AI summary
The planar antenna apparatus may include a planar, electrically conductive, patch antenna element having a geometric shape defining an outer perimeter, and a pair of spaced apart signal feedpoints along the outer perimeter of the planar, electrically conductive, patch antenna element and separated by a distance of one quarter of the outer perimeter to impart a traveling wave current distribution. The outer perimeter of the planar, electrically conductive, patch antenna element may be equal to about one operating wavelength thereof. The apparatus may provide dual circular or dual linear polarization. The planar patch element may relate to a full wave loop antenna as a compliment.