Multi-Antenna System Isolation via Orthogonal PIFA Arrangement
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Solution Overview
Problem
Existing multiple-antenna systems for mobile terminals face challenges in achieving high isolation between multiple frequency bands due to limited space and complex electromagnetic environments, which is crucial for advanced mobile communication functions.
Innovation Solution
A multiple-antenna system design utilizing two types of planar inverted-F antennas (PIFAs) with specific geometric configurations, including perpendicular orientation, U-shaped grooves, L-shaped slots, and L-shaped folded metallic ground planes, to achieve high isolation between antennas and frequency bands while minimizing space occupancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple PIFAs are used in a mobile terminal, then the mobile terminal can support multi-input multi-output (MIMO) technology and multiple frequency bands, but the isolation between multiple frequency bands cannot be met due to limited space and complex electromagnetic environment
Solution Approach 1:
The patent employs three-dimensional orthogonal arrangement of multiple PIFA antennas, where antennas are positioned along different spatial axes (x, y, z dimensions) to achieve maximum separation. This spatial dimensionality approach allows multiple antennas to coexist in limited mobile terminal space while maintaining required isolation between frequency bands, resolving the contradiction between multi-band support and frequency band isolation.
Solution Approach 2:
The patent implements nested arrangement of PIFA antennas within the mobile terminal housing, where antennas are positioned in a hierarchical structure with different mounting layers and depths. This nesting strategy enables compact packaging of multiple antennas while maintaining electromagnetic isolation through strategic positioning, thus supporting multi-frequency bands without compromising band isolation requirements.
2Productivity
If multiple PIFAs are arranged in limited space, then the mobile terminal can support MIMO technology, but the electromagnetic environment becomes complex and isolation between antennas deteriorates
Solution Approach 1:
The patent utilizes three-dimensional orthogonal positioning of MIMO antennas, arranging them along different spatial axes to maximize separation in all directions. This multi-dimensional arrangement reduces electromagnetic coupling and interference between antennas while maintaining compact form factor, enabling MIMO functionality without generating harmful electromagnetic interference.
Solution Approach 2:
The patent applies localized electromagnetic shielding structures and grounding arrangements around each PIFA antenna to control and contain electromagnetic fields. By optimizing the local electromagnetic environment around each antenna through targeted shielding and grounding, the patent minimizes mutual interference between antennas while maintaining overall system compactness for MIMO operation.
3Volume of moving object
If the size of PIFAs is reduced to fit mobile terminal, then the mobile terminal can accommodate multiple antennas, but the isolation between multiple frequency bands becomes difficult to achieve
Solution Approach 1:
The patent compensates for reduced antenna size by transitioning from two-dimensional planar arrangement to three-dimensional orthogonal configuration. This spatial dimensionality allows compact PIFA antennas to maintain adequate isolation distances through vertical and diagonal separation, achieving both miniaturization and frequency band isolation in mobile terminals.
Solution Approach 2:
The patent implements nested positioning of miniaturized PIFA antennas at different depths and layers within the terminal housing. This nested arrangement allows small antennas to be packed efficiently while maintaining electromagnetic isolation through strategic spatial separation, achieving both compact size and frequency band isolation requirements.
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
The design effectively provides high isolation between antennas and frequency bands, enabling efficient operation in multiple frequency bands while maintaining a compact size, suitable for next-generation mobile communication systems.
Implementation Method 1
power of the small-sized mobile terminal is transmitted to the base station in a form of an electromagnetic wave by using the antenna
Implementation Method 2
The PIFA has a resonant length that is only one fourth of an operating wavelength of an antenna
Data Source
Figure 1~2
Figure 3
Figure 4a
AI summary
The present invention provides a multiple-antenna system and a mobile terminal. The multiple-antenna system includes: a planar inverted-F antenna PIFA (10) of a first type, including a metallic ground plane (11), a dielectric plate (12), a radiation patch (13), a probe-type feeding unit (15), and a metallic shorting pin (16), where the radiation patch is located on an upper surface of the dielectric plate and is connected to the metallic ground plane by using the probe-type feeding unit and the metallic shorting pin; a PIFA (30) of a second type, perpendicular to the PIFA (10) of the first type, including a metallic ground plane (31), a radiation patch (33), a feeding unit (36), and a metallic shorted patch (34), where the radiation patch is connected to the metallic ground plane by using the feeding unit and the metallic shorted patch; and an isolation stub (2), located on an edge of a side, close to the PIFA of the second type, of the upper surface of the dielectric plate of the PIFA of the first type. In this way, isolation in the multiple-antenna system meets an operating requirement of the mobile terminal.