Elliptical Loop Antenna With Internal Short-Circuit Sections
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Solution Overview
Problem
Conventional loop antennas are difficult to reduce in size while maintaining performance, especially when integrated with other antennas in limited spaces such as automobiles, and they struggle to operate effectively in both MHz and GHz frequency ranges.
Innovation Solution
A loop antenna design featuring an elliptical shape with short-circuit sections inside the ellipse, allowing for impedance matching and resonance frequency adjustment, enabling compact size without compromising performance, and the inclusion of passive elements to enhance reception and reduce return loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional loop antenna is designed to operate at a specific frequency with appropriate length, then the antenna performance is maintained, but the antenna size cannot be reduced
Solution Approach 1:
The short-circuit section is nested inside the elliptical antenna element, placing one structural component within the space already occupied by another. This allows the short-circuiting function to be implemented without increasing the overall antenna footprint, resolving the contradiction between maintaining performance (through proper short-circuiting) and reducing size (by eliminating external extensions).
Solution Approach 2:
The invention changes the geometric parameters of the antenna from a conventional circular or linear shape to an elliptical shape with specific dimensional ratios. By optimizing the ellipse's major and minor axes and positioning the short-circuit section at specific points along the perimeter, the antenna achieves resonant frequencies that allow size reduction while maintaining operational performance across multiple bands.
2Reliability
If multiple separate antenna devices are used for different frequency bands, then each antenna operates effectively, but the number of attachment points increases and design is spoiled
Solution Approach 1:
The elliptical loop antenna with strategically placed short-circuit sections is designed to operate across multiple frequency bands (FM/AM broadcast, terrestrial digital broadcasting, GPS, VICS, ETC) simultaneously. By adjusting the ellipse geometry and short-circuit positioning, a single antenna structure achieves multi-band functionality, eliminating the need for separate whip antennas, film antennas, and other dedicated devices for each service.
Solution Approach 2:
The invention merges multiple antenna functions into a single integrated structure. The elliptical loop with its configurable short-circuit sections combines the capabilities of what would traditionally require separate GPS antennas, broadcast antennas, and communication antennas into one unified device, reducing complexity and eliminating the need for multiple attachment points on the vehicle.
3Volume of moving object
If antenna elements are disposed to overlap to reduce size, then the integrated device size is reduced, but antenna characteristics are impaired
Solution Approach 1:
The short-circuit section is nested within the elliptical antenna element's perimeter, allowing the antenna to achieve size reduction through internal configuration rather than external expansion. This nested arrangement maintains the electrical characteristics needed for proper operation while minimizing the overall footprint, enabling the antenna to be compact without requiring separation from other components.
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 allows for a significant reduction in size while maintaining desired performance, enabling effective operation in both MHz and GHz frequency ranges, even when overlapping with other antennas, and when mounted on metal surfaces.
Implementation Method 1
a short-circuit section provided inside the ellipse, the short-circuit section causing two points on the antenna element to be short-circuited
Data Source
Figure 1~2
Figure 3(a)~3(b)
Figure 4(a)~4(b)
AI summary
A loop antenna (3) in accordance with the present invention includes (i) an antenna element (31) having a shape that traces an ellipse and (ii) short-circuit sections (32a, 32b) provided inside the ellipse, each of the short-circuit sections (32a, 32b) causing two points on the antenna element to be short-circuited.