Wearable Frame Antenna Layout for Low-Band Matching
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Solution Overview
Problem
Miniaturization of wearable devices limits the lowest frequency band that metal frame antennas can reach, as adjusting the length of one part of the antenna affects the matching of the other part, restricting flexibility and performance.
Innovation Solution
Incorporating a grounding member within a conducting frame with separate parts, allowing the extension of the antenna length without altering the device's size, and adjusting the impedance matching by modifying the grounding member's length to achieve better frequency band matching and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the antenna length is extended to reach lower frequency bands, then the antenna matching is improved, but the device size increases
Solution Approach 1:
The grounding member extends the antenna grounding path in the vertical dimension (through the circuit board thickness) rather than only in the horizontal plane. This allows the first antenna to achieve sufficient electrical length for lower frequency operation without increasing the device's footprint area, effectively resolving the contradiction between antenna performance and device size.
2Adaptability or versatility
If the length of one part of the antenna is adjusted, then the frequency band is extended, but the antenna matching of other parts is affected
Solution Approach 1:
The antenna system is segmented into multiple independent antennas (first antenna with first part and grounding member, second antenna with second part), each with its own feeding terminal and grounding terminal. This segmentation allows each antenna to be independently optimized for different frequency bands without affecting the matching of other antennas, resolving the contradiction between frequency adaptability and matching reliability.
3Adaptability or versatility
If the antenna length is increased to improve low frequency performance, then the operating frequency band is extended, but the device appearance is compromised
Solution Approach 1:
The grounding member is nested within the device structure, utilizing the internal space between the conducting frame and the circuit board. This nested configuration allows the antenna grounding path to be extended for lower frequency operation without altering the external dimensions or appearance of the wearable device, effectively resolving the contradiction between frequency band adaptability and appearance maintenance.
Data Source
AI summary
A wearable device includes a conducting frame, a circuit board, and a grounding member. The conducting frame includes a first part and a second part that are separated. The circuit board has a system grounding surface and is disposed inside the conducting frame. The grounding member is disposed inside the conducting frame and connected to the first part. The first part and the grounding member are formed as a first antenna. The first part has a first feeding terminal. The grounding member has a first grounding terminal, and the first grounding terminal is connected to the system grounding surface of the circuit board. The second part is formed as a second antenna. The second antenna has a second feeding terminal, a second grounding terminal, and a third grounding terminal. The second and the third grounding terminals are connected to the system grounding surface of the circuit board.