Antenna Device Phase Control for Radiation Efficiency
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Solution Overview
Problem
The existing antenna devices with closely arranged radiating elements suffer from reduced radiation efficiency due to electric field coupling, which causes currents flowing through the parasitic radiating element to weaken each other, leading to insufficient radiation performance, especially in wide frequency range applications.
Innovation Solution
The antenna device incorporates a first and second radiating element coupled via an antenna coupling element, comprising a first coil and a second coil, where the coils are electromagnetically coupled, and the radiating elements are electrically coupled through parasitic capacitance, with the phase difference between currents from electromagnetic and electric field couplings controlled to be equal to or less than 90 degrees, preventing cancellation of currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the radiating elements are arranged close to each other to reduce antenna space, then the antenna space is decreased, but the radiation efficiency is lowered due to current cancellation from electric field coupling
Solution Approach 1:
The patent introduces an antenna coupling element as an intermediary component between the first and second radiating elements. This coupling element controls the current distribution and electromagnetic coupling between the radiating elements, preventing harmful current cancellation while maintaining compact arrangement. The coupling element acts as a mediator that manages the interaction between closely spaced radiating elements to preserve radiation efficiency.
2Adaptability or versatility
If the radiating elements are arranged close to each other to support wide frequency range, then the frequency coverage is widened, but the currents from electromagnetic and electric field coupling weaken each other
Solution Approach 1:
The patent employs parameter changes by adjusting the inductance values of the coils in the antenna coupling element and modifying the geometric parameters of the radiating elements. By changing these parameters, the resonant frequencies and coupling characteristics are optimized to maintain strong currents across a wide frequency range without cancellation effects. The coupling element's inductance is specifically tuned to control the phase and magnitude of currents.
3Adaptability or versatility
If the antenna coupling element is used to control power feeding, then the wide frequency range is supported, but the phase difference causes current cancellation reducing radiation efficiency
Solution Approach 1:
The patent applies dynamics by making the antenna coupling element's characteristics frequency-dependent. The coupling element dynamically adapts its coupling strength and phase relationship across different frequencies through its coil configuration and inductance values. This dynamic behavior ensures that at any operating frequency within the wide range, the currents are phased correctly to avoid cancellation, while still providing the needed frequency versatility.
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 significantly enhances radiation efficiency by ensuring currents from electromagnetic and electric field couplings do not cancel each other, particularly in the high frequency band, thereby improving overall performance and supporting broadband communication.
Implementation Method 1
a second coil coupled to the second radiating element and coupled to the first coil via an electromagnetic field
Implementation Method 2
The first radiating element and the second radiating element are coupled to each other via an electric field
Data Source
AI summary
An antenna device includes first and second radiating elements, a first coil coupled to the first radiating element or a feeding circuit, and a second coil coupled to the second radiating element and coupled to the first coil via an electromagnetic field. The first and second radiating elements are coupled to each other via an electric field. At a resonant frequency defined by the antenna coupling element and the second radiating element, the absolute value of the phase difference between a current flowing into the second radiating element due to the electromagnetic field of the first coil and the second coil and a current flowing into the second radiating element due to the electric field is equal to or less than about 90 degrees.