Antenna Structure Slits for Hearing Aid Compatible PCB Field Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic fields produced by printed circuit boards in electronic devices can degrade hearing aid compatibility and communication performance by radiating to the front and side surfaces, affecting devices like hearing aids with telecoils.
Innovation Solution
An electronic device with a printed circuit board and an antenna structure featuring slits and openings to redirect magnetic fields towards the rear surface, reducing radiation to the front and side surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a shielding member is disposed on the rear surface of the printed circuit board to block magnetic fields, then magnetic field radiation to the front and side surfaces is reduced, but magnetic field radiation to the rear surface increases
Solution Approach 1:
The shielding member is divided into multiple regions with different properties: a first region facing the printed circuit board with high magnetic permeability to attract and guide magnetic fields, and a second region facing the rear surface with low magnetic permeability to allow magnetic field passage. This segmentation enables differential control of magnetic field radiation in different directions, resolving the contradiction between blocking front/side radiation and allowing rear radiation.
Solution Approach 2:
Different regions of the shielding member are assigned different magnetic permeability characteristics tailored to their specific functions. The first region (facing the PCB) has high magnetic permeability to concentrate and guide magnetic fields away from the front and side surfaces, while the second region (facing the rear surface) has low magnetic permeability to permit magnetic field passage to the rear. This local differentiation of properties resolves the directional radiation contradiction.
2Ease of operation
If wires are arranged on the printed circuit board to supply power, then electrical connection between battery and electronic components is achieved, but magnetic fields are produced that degrade hearing aid compatibility and communication performance
Solution Approach 1:
The shielding member acts as an intermediary between the printed circuit board (with its power-supplying wires) and the external environment (hearing aids and communication devices). It selectively blocks magnetic fields generated by the wires from radiating toward the front and side surfaces where hearing aids and communication devices are located, while allowing magnetic field passage to the rear surface. This intermediary function protects against harmful magnetic field radiation without interfering with the electrical connection capability of the wires.
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
Improves hearing aid compatibility and communication performance by minimizing magnetic field radiation to the front and side surfaces, enhancing test and communication performance.
Implementation Method 1
a magnetic field (e.g., H-field) may be produced according to the flow of the current
Data Source
AI summary
An electronic device includes: a housing including a front surface plate, a rear surface plate, and a side surface member between the front surface plate and the rear surface plate; a printed circuit board inside the housing and including a first wire; and an antenna structure between the printed circuit board and the rear surface plate, where the antenna structure includes a first slit at a position corresponding to a position of the first wire.