Coupled Annular Circular Antenna for Compact Wearable Positioning
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Solution Overview
Problem
Smart wearable devices face challenges in implementing circularly polarized antennas due to size constraints, leading to poor satellite positioning performance and multipath interference, with existing designs being complex and limited to specific radiator sizes.
Innovation Solution
A circularly polarized antenna design for wearable devices featuring a coupling excitation unit with a coupling branch and tuning elements, allowing electromagnetic coupling without direct electrical connections, enabling flexible frequency tuning for radiators of varying sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If linearly polarized antennas are used in wearable devices due to size constraints, then device size is reduced, but satellite positioning performance deteriorates
Solution Approach 1:
The patent changes the polarization parameter from linear to circular, which fundamentally alters the antenna's electromagnetic field characteristics. This enables the antenna to receive signals from satellites with any polarization orientation, thereby improving positioning performance while maintaining the compact wearable device form factor
Solution Approach 2:
The patent employs a coupling excitation unit with adjustable coupling coefficients that can dynamically optimize the excitation of orthogonal modes in the annular radiator. This dynamic adjustment capability allows the antenna to maintain optimal circular polarization performance across different operating conditions and device configurations
2Reliability
If circularly polarized antennas are implemented in wearable devices, then satellite signal reception intensity is improved, but device complexity increases
Solution Approach 1:
The patent merges the feeding network and grounding structure into a unified coupling excitation unit that directly couples to the annular radiator. This integration eliminates the need for separate feeding antennas and complex impedance matching networks, reducing overall device complexity while achieving circular polarization
Solution Approach 2:
The annular radiator serves multiple functions: it acts as the radiating element, the resonant structure for circular polarization, and the grounding reference. This multi-functionality reduces the number of separate components needed, thereby simplifying the overall antenna structure
3Reliability
If existing coupling structure designs are used for annular radiators, then circular polarization is achieved, but adaptability to different radiator sizes is limited
Solution Approach 1:
The patent employs a coupling excitation unit with adjustable coupling coefficients that can dynamically optimize the excitation of orthogonal modes in the annular radiator. This dynamic adjustment capability allows the antenna to maintain optimal circular polarization performance across different operating conditions and device configurations
Solution Approach 2:
The patent provides multiple embodiments with different coupling structure configurations (direct coupling, capacitive coupling, inductive coupling) that can be selected based on the specific radiator size and operating frequency, enabling broad adaptability across different wearable device form factors
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
Enhances satellite signal reception intensity and reduces multipath interference, providing accurate positioning and improved design flexibility for wearable devices.
Implementation Method 1
a coupling excitation unit arranged in proximity to the annular radiator and electromagnetically coupled to the annular radiator
Implementation Method 2
the first tuning element being configured for tuning a resonant frequency of the circularly polarized antenna
Data Source
Figure 1A~2
Figure 3~4
Figure 5~6
AI summary
The present disclosure relates to the technical field of electronic devices and provides a circularly polarized antenna and a wearable device. The circularly polarized antenna includes a circuit board (10), an annular radiator (20) arranged at a distance from the circuit board (10), and a coupling excitation unit, where the coupling excitation unit is positioned close to the annular radiator (20) and electromagnetically coupled therewith, and the coupling excitation unit includes a first coupling branch (30) and a first tuning element, a first end of the first coupling branch (30) being electrically connected to a feeding portion of the circuit board (10), and a second end of the first coupling branch (30) being electrically connected to a reference ground of the circuit board (10) via the first tuning element. An annular current loop is formed between the coupling excitation unit and the circuit board (10). In the embodiments of this disclosure, since there is no direct electrical connection between the annular radiator and other electrical components, and the first coupling branch is grounded via the first tuning element, the antenna design provides improved practicality and flexibility.