Multi-band Antenna Using Tunable Inductor and Segmented Housing
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Solution Overview
Problem
The challenge is to design wireless communications circuitry for electronic devices that effectively incorporates conductive structures while maintaining satisfactory radio-frequency performance across multiple operating frequencies, particularly in compact form factors where conductive housing components can impact antenna performance.
Innovation Solution
The solution involves forming antennas using a resonating element and an antenna ground, where the resonating element has distinct portions for different frequency bands, and an adjustable inductor is used to tune the antenna, allowing the antenna to cover multiple communications bands by utilizing peripheral conductive housing structures and an extended antenna ground to create inverted-F antenna resonating elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conductive housing structures are used in compact electronic devices, then device structural integrity and aesthetic appearance are improved, but radio-frequency performance of antennas is degraded
Solution Approach 1:
The antenna resonating element is segmented into multiple portions (first portion, second portion, third portion) that can be independently configured. The conductive housing is divided into separate conductive structures (first conductive structure, second conductive structure) that are positioned at specific locations to minimize interference with antenna operation while maintaining structural integrity.
Solution Approach 2:
Different portions of the antenna resonating element have different electrical lengths and resonant frequencies. The first portion has a first electrical length for first band resonance, the second portion has a second electrical length for second band resonance, and the third portion has a third electrical length for third band resonance. Conductive structures are strategically positioned at specific locations (e.g., away from feed points or at null points) to minimize their harmful impact on RF performance while maintaining overall structural integrity.
2Device complexity
If a single antenna is designed to cover multiple frequency bands, then device complexity and number of components are reduced, but achieving satisfactory performance across all bands becomes more difficult
Solution Approach 1:
A single antenna structure serves multiple functions by covering three different communications bands (first band, second band, third band) through its different portions. The first portion resonates at first band frequencies, the second portion resonates at second band frequencies, and the third portion resonates at third band frequencies, allowing one antenna to replace what would traditionally require multiple separate antennas.
Solution Approach 2:
The antenna incorporates an adjustable component (tunable inductor) that can dynamically adjust the resonant frequencies of the antenna portions. This allows the antenna to be tuned to optimize performance across different bands and adapt to varying operational requirements, ensuring satisfactory performance across all three bands despite the challenging multi-band design.
3Reliability
If the antenna resonating element is made longer to cover lower frequency bands, then low band coverage is improved, but the antenna size and device form factor increase
Solution Approach 1:
The antenna structure utilizes three-dimensional space efficiently by arranging resonating elements in different spatial configurations. The inverted-F antenna portions and the positioning of conductive structures allow the antenna to achieve long electrical lengths for low band resonance without proportionally increasing the physical footprint, as the current paths are folded and arranged in multiple dimensions within the compact device 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 enables improved wireless communications by ensuring satisfactory performance across various frequency bands, allowing for compact and efficient wireless communications circuitry in electronic devices with conductive housing components.
Implementation Method 1
The antenna resonating element may have a longer portion that resonates at first communications band frequencies and a shorter portion that resonates at second communications band frequencies above the first communications band frequencies
Implementation Method 2
An adjustable component such as a tunable inductor may be coupled between the antenna resonating element and antenna ground for tuning the antenna
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. An extended portion of the antenna ground may form an inverted-F antenna resonating element portion of the antenna resonating element. The antenna resonating element may be formed from a peripheral conductive electronic device housing structure that is separated from the antenna ground by an opening. A first antenna feed may be coupled between the peripheral conductive electronic device housing structures and the antenna ground across the opening. A second antenna feed may be coupled to the inverted-F antenna resonating element portion of the antenna resonating element.