MIMO Antenna Feeding Circuit for Multi-Band Isolation in Shared Radiators
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Solution Overview
Problem
The limited space within electronic devices constrains the frequency band coverage of MIMO antennas, and the need for high isolation and multi-band operation is crucial, especially with the increasing demand for high-speed data transmission in wireless communication systems like 5G, where multiple antennas share a radiator.
Innovation Solution
An antenna structure with a first circuit that excites half-wavelength and one-time wavelength modes in both CM and DM modes, utilizing symmetrical feeding elements and inductors/capacitors to ensure different current paths for these modes, maintaining high isolation and expanding the operating bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If multiple antennas share a radiator to reduce space, then space utilization is improved, but isolation between antennas deteriorates
Solution Approach 1:
The patent divides the single radiator into multiple independent radiating elements (first radiator and second radiator) that can be independently controlled. Each radiating element has its own feeding circuit, allowing independent signal transmission and reception, thereby maintaining isolation between antenna ports while sharing the overall antenna structure space.
Solution Approach 2:
The patent employs switching circuits that can dynamically switch between different operating modes (CM mode and DM mode). By dynamically changing the connection state of switching elements, the antenna can adaptively adjust its radiation characteristics and isolation properties based on different working conditions, maintaining high isolation across multiple frequency bands.
2Ease of manufacture
If antenna structure is simplified to reduce device complexity, then manufacturing ease is improved, but frequency band coverage deteriorates
Solution Approach 1:
The patent designs a multi-functional antenna structure that can operate in multiple frequency bands (first frequency band and second frequency band) and multiple modes (CM mode and DM mode) using a single shared radiator structure. The switching circuit enables the antenna to universally support different communication standards and frequency requirements without requiring separate antenna elements for each band.
Solution Approach 2:
The patent changes the electrical parameters (impedance, resonance frequency) of the antenna by reconfiguring the switching circuit states. By adjusting which switching elements are conductive or high-impedance, the antenna's resonant frequency and impedance characteristics are dynamically changed to match different frequency bands, expanding frequency coverage without adding physical complexity.
3Reliability
If isolation between modes is increased to maintain signal integrity, then communication reliability is improved, but bandwidth is reduced
Solution Approach 1:
The patent uses dynamic switching to control the isolation between CM and DM modes. The switching circuit can be configured to provide high isolation when needed (for clear signal separation) or lower isolation when bandwidth extension is required. This dynamic adjustment allows the system to optimize the trade-off between signal integrity and bandwidth based on current communication requirements.
Solution Approach 2:
The patent pre-configures multiple switching states that correspond to different operating conditions. The switching circuit is designed in advance to provide predetermined isolation levels for different mode combinations, allowing the system to quickly switch between high-isolation and bandwidth-mode operations without real-time complex control, thus maintaining both signal integrity and bandwidth efficiency.
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 solution enables the antenna to operate in multiple resonant frequencies with high isolation, effectively utilizing limited space and enhancing the practicality of MIMO systems by expanding bandwidth and maintaining signal integrity.
Implementation Method 1
A first circuit of the antenna structure excites modes such as a half-wavelength mode, a one-time wavelength mode, and a three-half-wavelength mode of a CM mode, and may further excite modes such as a half-wavelength mode, a one-time wavelength mode, and a three-half-wavelength mode of a DM mode
Data Source
AI summary
An electronic device includes an antenna structure having an antenna radiator, a first circuit, a first feeding element, and a second feeding element. The first circuit comprises feeding input ports configured to input electrical signals of the first feeding element and the second feeding element, and feeding output ports configured to feed processed electrical signals to the antenna radiator. The electrical signal of the first feeding element has a same phase on the feeding input ports. The electrical signal of the second feeding element has opposite phases on the feeding input ports.