Coupled-Feed Dual-Band Antenna for Cross-Band Interference Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-frequency radiating elements in dual-band antennas cause interference to low-frequency radiating elements due to electromagnetic wave induction, affecting signal radiation and interference.
Innovation Solution
A dual-band antenna design with a first radiating element using coupled feeding through a coupling structure, adjusting the electrical length of the radiator arm and feeding apparatus to prevent interference, allowing the high-frequency element to operate outside the low-frequency band without altering the radiator arm's size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the high-frequency radiating element uses a conventional feeding apparatus with direct connection, then the structure is simple, but the equivalent monopole antenna generates low-frequency induced current that interferes with the low-frequency radiating element
Solution Approach 1:
The patent introduces a coupling structure as an intermediary between the high-frequency feeding apparatus and the radiator arm. This coupling structure acts as a frequency selective element that blocks low-frequency currents while allowing high-frequency signals to pass through, thereby preventing the generation of low-frequency induced current that would interfere with the low-frequency radiating element.
Solution Approach 2:
The patent modifies the electrical length parameters of the coupling structure and feeding apparatus to create a frequency selective effect. By adjusting the electrical length to be less than one-quarter of the low-frequency wavelength, the system changes its impedance characteristics to block low-frequency currents while maintaining high-frequency signal transmission.
2Object-generated harmful factors
If the sum of electrical lengths of the radiator arm and feeding apparatus is reduced to prevent low-frequency radiation, then interference to the low-frequency element is avoided, but the high-frequency element's operating characteristics are affected
Solution Approach 1:
The patent applies different electrical length characteristics to different parts of the feeding system. The coupling structure has a specific electrical length optimized for blocking low frequencies, while the radiator arm maintains its standard high-frequency resonant length. This local differentiation allows each component to optimize its function without compromising the other frequency band's performance.
Solution Approach 2:
The coupling structure serves as a frequency-selective intermediary that decouples the low-frequency blocking function from the high-frequency radiation function. This allows the radiator arm to maintain its optimal electrical length for high-frequency operation while the coupling structure handles the low-frequency rejection through its own electrical length characteristics.
3Object-generated harmful factors
If the radiator arm size is changed to adjust the electrical length sum, then the operating frequency can be moved outside the low-frequency band, but the normal operation of the radiator unit is influenced
Solution Approach 1:
The patent divides the feeding system into separate functional segments: the coupling structure handles frequency selection and low-frequency blocking, while the radiator arm handles high-frequency radiation. This segmentation allows independent optimization of each component - the radiator arm maintains its standard size for reliable high-frequency operation, while the coupling structure's electrical length is adjusted to achieve frequency separation.
4Ease of manufacture
If a coupled feeding manner is used with adjustable coupling structure, then only the coupling structure size needs to be changed without affecting the radiator arm, but the device complexity increases
Solution Approach 1:
The coupling structure is designed as a standardized intermediary component with adjustable electrical length through simple geometric parameter changes. This intermediary approach allows frequency tuning to be achieved by modifying only the coupling structure's dimensions rather than the entire antenna system, providing manufacturing flexibility while keeping the radiator arm unchanged.
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 effectively reduces interference between high- and low-frequency elements, enabling normal operation of the low-frequency element by blocking electromagnetic waves outside its frequency band, thus maintaining signal integrity.
Implementation Method 1
the coupling structure may transmit a signal of the first frequency band, and block a signal of the second frequency band
Implementation Method 2
the first radiating element transmits a signal outwards as a transmit antenna
Implementation Method 3
the equivalent monopole antenna generates a low-frequency induced current under the influence of an electromagnetic wave radiated by the low-frequency element
Data Source
AI summary
The present disclosure relates to dual-band antennas and antenna arrays. One example dual-band antenna includes a first radiating element and a second radiating element that are disposed on a reflection plate. An operating frequency band of the first radiating element is a first frequency band, and an operating frequency band of the second radiating element is a second frequency band. A minimum frequency of the first frequency band is greater than a maximum frequency of the second frequency band. The first radiating element includes a first feeding apparatus and a first radiator unit, the first feeding apparatus includes a coupling structure coupled to the first radiator unit, and the first feeding apparatus is used for coupled feeding for the first radiator unit by using the coupling structure.