Circularly Polarized Antenna Single-Fed Bandwidth
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Solution Overview
Problem
Existing circularly polarized antennas face challenges with narrow operating bandwidth, impedance matching difficulties, and bulky size, particularly in single-fed designs, while dual-fed antennas offer wide bandwidth but are cumbersome.
Innovation Solution
A compact circularly polarized antenna design incorporating a dielectric substrate with a closed-loop radiating element, micro-strip radiating element, feeding element, and grounding element, which divides input signal power into 90-degree out-of-phase components to achieve circular polarization, utilizing an FR-4 substrate with specific dimensions and configurations for the radiating and feeding elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-fed circularly polarized antenna is used, then the device complexity is reduced, but the operating bandwidth becomes narrow and impedance matching becomes difficult
Solution Approach 1:
The radiating element is divided into two separate arms (first radiating arm and second radiating arm) with different geometries. The first arm includes a rectangular resonant structure while the second arm includes a triangular resonant structure. This segmentation allows each arm to contribute differently to the overall radiation pattern and impedance characteristics, enabling wider bandwidth operation with a single feed structure.
2Adaptability or versatility
If a dual-fed circularly polarized antenna is used, then the operating bandwidth and circular polarization characteristic are improved, but the device becomes bulky and heavy
Solution Approach 1:
The patent combines the functions of two separate feed structures into a single integrated feeding element. The feeding element includes a feed line with specific impedance that directly connects to both radiating arms through a shared ground structure. This merging eliminates the need for two separate feed networks, reducing overall antenna weight and complexity while maintaining the bandwidth and circular polarization performance typically associated with dual-fed designs.
3Adaptability or versatility
If a dual-fed circularly polarized antenna is used, then the operating bandwidth and circular polarization characteristic are improved, but the device size increases
Solution Approach 1:
The radiating arms are arranged in a nested configuration where the triangular resonant structure of the second arm is positioned within or adjacent to the rectangular resonant structure of the first arm. Both arms share a common ground structure and are fed from a single feed line. This nesting arrangement allows the antenna to achieve wide bandwidth performance typically requiring larger, dual-fed structures while maintaining a compact overall volume.
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 wide impedance bandwidth of 413 MHz, maintains a high axial ratio bandwidth of 116 MHz, and provides a peak gain ranging from 4.5 dBi to 6.2 dBi, while being more compact compared to traditional dual-fed antennas.
Implementation Method 1
a closed-loop radiating element (13), a micro-strip radiating element (14), a feeding element (15), and a grounding element (12)... The feeding element (15) is formed on the first surface of the dielectric substrate, is surrounded by the closed-loop radiating element (13), is coupled to the first ends of the first and second segments (141, 142) of the micro-strip radiating element (14), and is operable so as to receive an input signal, and so as to divide a power of the input signal into first and second components that are ninety-degree out-of-phase
Data Source
AI summary
A circularly polarized antenna includes a dielectric substrate, a closed-loop radiating element, a micro-strip radiating element, a feeding element, and a grounding element. The closed-loop radiating element is formed on a first surface of the dielectric substrate. The micro-strip radiating element is formed on the first surface of the dielectric substrate, is surrounded by the closed-loop radiating element, and is coupled to the closed-loop radiating element. The feeding element is formed on the first surface of the dielectric substrate, is surrounded by the closed-loop radiating element, and is coupled to the micro-strip radiating element. The grounding element is formed on a second surface of the dielectric substrate.