MIMO Antenna With Variable Impedance Parasitic Element
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Solution Overview
Problem
Conventional MIMO antenna apparatuses face challenges in achieving high transmission capacity and quality on small-sized devices like mobile phones, as they struggle to mount multiple antenna elements and effectively control directivity for multiple transmitter/receiver circuits.
Innovation Solution
A MIMO antenna apparatus with multiple feeding antenna elements, parasitic elements, variable impedance load elements, and a controller that adjusts impedance values to maximize received signal levels, allowing for adaptive control of directivity and communication method switching between MIMO and SISO.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple antenna elements are mounted on small-sized devices, then transmission capacity is improved, but device size and complexity increase
Solution Approach 1:
The antenna system is segmented into feeding antenna elements and parasitic elements, where the parasitic elements are strategically positioned to interact electromagnetically with the feeding elements. This segmentation allows the antenna to achieve MIMO functionality with fewer physical antenna elements, reducing device size while maintaining transmission capacity.
Solution Approach 2:
Parasitic elements serve as intermediaries between the feeding antenna elements and the wireless signals. These parasitic elements, when connected to variable impedance load elements, mediate the electromagnetic interaction to control directivity and signal reception, enabling compact MIMO implementation.
2Reliability
If directivity is controlled for multiple transmitter/receiver circuits, then communication quality is improved, but device complexity increases
Solution Approach 1:
The system controls directivity by changing the impedance parameters of the variable impedance load elements connected to parasitic elements. By adjusting impedance values (such as reactance values), the system optimizes signal reception quality without requiring complex mechanical or structural adjustments, thereby maintaining relatively simple device architecture.
3Productivity
If variable impedance load elements are used to maximize received signal levels, then transmission capacity is improved, but power consumption increases
Solution Approach 1:
The variable impedance load elements are applied selectively to specific parasitic elements rather than all antenna elements. This partial application allows the system to achieve the necessary signal level optimization for improved transmission capacity while minimizing the number of active control elements, thereby reducing overall power consumption.
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 high transmission capacity and quality MIMO communication on small devices by optimizing signal levels and reducing signal differences between antenna elements, while maintaining low power consumption and a compact design.
Implementation Method 1
at least one parasitic element which is provided to be electromagnetically coupled to each of the plurality of feeding antenna elements
Implementation Method 2
The controller controls an impedance value of the variable impedance load element based on the received signal levels detected by the comparator, such that the received signal level of the wireless signal having the minimum received signal level is substantially maximized
Data Source
AI summary
A MIMO antenna apparatus includes a plurality of feeding antenna elements, a parasitic element electromagnetically coupled to each feeding antenna element, and a variable impedance load element connected to the parasitic element. A signal level comparator circuit detects received signal levels of received wireless signals and compares the received signal levels with each other, and thus detects the minimum received signal level. A controller controls an impedance value of the variable impedance load element based on the received signal levels detected by the signal level comparator circuit, such that the received signal level of the wireless signal having the minimum received signal level is substantially maximized.