Rotating Electronic Device Antenna with Parasitic Element
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Solution Overview
Problem
It is challenging to design electronic device antenna structures that achieve desired performance levels, especially in compact devices with conductive housing structures, as these can interfere with antenna operation and affect wireless communication efficiency across multiple frequency bands.
Innovation Solution
The electronic device incorporates a metal housing with a dielectric substrate-mounted antenna resonating element between conductive walls, featuring a parasitic element to redirect radio-frequency signals and ensure efficient operation across 2.4 GHz and 5 GHz frequency bands, regardless of the device's lid position, by optimizing the cavity depth and slot configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the antenna resonating element is mounted entirely within the lower housing between conductive walls, then antenna performance is improved by reducing interference from conductive housing structures, but device size increases and compactness is reduced
Solution Approach 1:
The antenna resonating element is nested within the lower housing between the first and second conductive walls, with the dielectric substrate recessed into the lower housing. This nesting arrangement allows the antenna to be fully contained within the existing housing structure, minimizing the increase in device volume while improving antenna performance by isolating it from interfering conductive structures.
2Object-affected harmful factors
If the lower slot width is reduced to improve device aesthetics and minimize foreign object interference, then antenna efficiency in the 5 GHz band is maintained, but antenna efficiency in the 2.4 GHz band deteriorates
Solution Approach 1:
A parasitic antenna resonating element is introduced as an intermediary component mounted to the first conductive wall. This parasitic element specifically addresses the 2.4 GHz band by redirecting radio-frequency signals from the lower slot towards and through the upper slot, thereby maintaining antenna efficiency in the 2.4 GHz band even when the lower slot width is reduced to minimize foreign object interference and improve aesthetics.
3Reliability
If the cavity depth is optimized to improve antenna efficiency in the 2.4 GHz band, then antenna performance is improved, but device complexity increases
Solution Approach 1:
The cavity depth between the antenna resonating element and the conductive structures is optimized to a specific range (between one-sixteenth and one-quarter of a wavelength at 2.4 GHz) to improve antenna efficiency. Additionally, a protruding portion is added to the second conductive wall to extend beyond the dielectric substrate edge, further refining the cavity configuration. These parameter optimizations enhance antenna performance while maintaining a relatively simple overall structure that can be integrated into the housing.
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
This configuration enhances antenna efficiency across multiple frequency bands, maintaining satisfactory performance in both closed and open positions while minimizing the risk of foreign object interference and optimizing device aesthetics.
Implementation Method 1
The antenna may convey radio-frequency signals in a 5 GHz frequency band through the lower slot when the upper housing is in the closed position and through the upper and lower slots when the upper housing is in the open position
Implementation Method 2
The parasitic antenna resonating element may be configured to resonate in the 2.4 GHz frequency band. The parasitic antenna resonating element may redirect radio-frequency signals in the 2.4 GHz frequency band from the lower slot towards and through the upper slot
Implementation Method 3
Conductive structures such as a sheet metal member may be formed in the lower housing and may short the first conductive wall to the second conductive wall. The conductive structures may form a cavity back for the antenna resonating element
Data Source
AI summary
An electronic device may have an upper housing with a display and a lower housing with a keyboard. The upper housing may rotate between open and closed positions. The lower housing may include a first conductive wall separated from the upper housing by an upper slot and a second conductive wall separated from the upper housing by a lower slot. An antenna resonating element may be mounted within the lower housing and may convey signals in low and high frequency bands through the lower slot when the upper housing closed. The resonating element may be grounded to the second conductive wall and may be separated from a conductive cavity wall by at least one-sixteenth of a wavelength in the low frequency band. A parasitic element may be used to redirect signals in the low frequency band towards and through the upper slot when the upper housing open.