Tunable Parasitic Antenna Element for RF Housing
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Solution Overview
Problem
The challenge is to design wireless communications circuitry for electronic devices that effectively integrates antennas with conductive structures while maintaining satisfactory radio-frequency performance across a range of operating frequencies, particularly in compact form factors.
Innovation Solution
The solution involves forming antennas using a peripheral conductive housing structure with adjustable inductors that allow tuning for both high and low communications bands, utilizing a parasitic monopole or loop antenna resonating element located in openings within the conductive housing, and coupling these elements to an antenna ground for optimal frequency response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conductive structures are incorporated into electronic device housing, then device strength and shielding are improved, but radio-frequency performance of antennas is degraded
Solution Approach 1:
The antenna system is segmented into multiple independent resonating elements (first resonating element for low band, second resonating element for high band) that can be independently tuned. This segmentation allows each element to be optimized for specific frequency ranges, maintaining RF performance while coexisting with conductive housing structures.
Solution Approach 2:
Adjustable inductors are introduced as intermediary components between the resonating elements and the conductive housing ground. These inductors act as mediators that allow precise control of the electromagnetic coupling, enabling the antenna to achieve desired resonance frequencies despite the presence of conductive housing structures.
2Volume of moving object
If antenna structures are made compact to satisfy small form factor requirements, then device size is reduced, but frequency coverage and performance are degraded
Solution Approach 1:
The antenna system achieves multi-functionality by integrating both low band and high band resonating elements within a single compact antenna structure. The first resonating element handles low band frequencies while the second resonating element handles high band frequencies, allowing one antenna system to perform multiple frequency coverage functions that would traditionally require separate antenna structures.
Solution Approach 2:
The antenna incorporates adjustable inductors that enable dynamic tuning of resonance frequencies. This dynamic capability allows the compact antenna structure to adapt its electrical characteristics to achieve proper resonance at different frequency bands, compensating for the size constraints that would otherwise limit frequency coverage.
3Device complexity
If fixed antenna structures are used, then device complexity is reduced, but adaptability to different frequency bands is limited
Solution Approach 1:
The antenna structure incorporates adjustable inductors that provide dynamic tuning capability. These inductors can be adjusted to change the electrical length and resonance characteristics of the resonating elements, enabling the antenna to adapt to different frequency bands without requiring complex reconfigurable structures or multiple fixed antenna designs.
Solution Approach 2:
The antenna achieves frequency band adaptability by changing electrical parameters (inductance values) rather than changing the physical structure. By adjusting the inductance of the adjustable inductors, the resonance frequencies of both low band and high band elements can be tuned, providing versatile frequency coverage while maintaining a relatively simple fixed physical structure.
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 approach enables electronic devices to achieve improved wireless communications performance by ensuring reliable coverage of multiple frequency bands without compromising on device size or conductive structure interference, allowing for real-time adjustments to maintain effective antenna performance.
Implementation Method 1
Antenna tuning in the higher communications band may be implemented using an adjustable inductor in the parasitic element
Implementation Method 2
Antenna tuning in the lower communications band may be implemented using an adjustable inductor that couples the antenna resonating element to the antenna ground
Implementation Method 3
The antenna resonating element arm may have a shorter portion that resonates at higher communications band frequencies and a longer portion that resonates at lower communications band frequencies
Data Source
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AI summary
Electronic devices may be provided that include radio-frequency transceiver circuitry and antennas. An antenna may be formed from an antenna resonating element and an antenna ground. The antenna resonating element may have a shorter portion that resonates at higher communications band frequencies and a longer portion that resonates at lower communications band frequencies. The resonating element may be formed from a peripheral conductive electronic device housing structure that is separated from the antenna ground by an opening. A parasitic monopole antenna resonating element or parasitic loop antenna resonating element may be located in the opening. Antenna tuning in the higher communications band may be implemented using an adjustable inductor in the parasitic element. Antenna tuning in the lower communications band may be implemented using an adjustable inductor that couples the antenna resonating element to the antenna ground.