Capacitive Coupling Between Monopole and Slot Antennas for Extended Bandwidth
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Compact form factors in wireless devices lead to reduced space for antennas, tighter tolerances, and unwanted parasitic capacitance, making it challenging to achieve desired bandwidth and manufacturing robustness without adding new structures or components.
Innovation Solution
A multi-antenna structure comprising a monopole-like or loop-like antenna that capacitively feeds a slot-like antenna, utilizing existing parasitics to create a combined antenna with extended bandwidth, allowing dual-band operation without additional parts or materials, and independently tunable components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a compact form factor is used for wireless devices, then the device size is reduced and aesthetics are improved, but antenna space is reduced and bandwidth is limited
Solution Approach 1:
The patent combines a monopole-like antenna and a slot-like antenna into a single integrated structure where the slot-like antenna is formed within the monopole antenna body. This merging allows both antenna types to coexist in a compact space, enabling dual-band operation and extended bandwidth without increasing overall device volume.
Solution Approach 2:
The monopole-like antenna structure serves multiple functions: it acts as a standalone antenna for one frequency band, simultaneously provides capacitive coupling to feed the slot-like antenna for another frequency band, and maintains mechanical support functions. This multi-functionality achieves bandwidth extension without adding separate antenna structures.
2Volume of moving object
If compact form factor is used, then device size is reduced, but manufacturing tolerances become tighter and more problematic
Solution Approach 1:
The patent uses adjustable capacitive coupling between the monopole and slot-like antenna structures, allowing bandwidth and frequency characteristics to be tuned by changing the coupling parameters rather than requiring precise manufacturing tolerances. The vertical spacing and coupling capacitance can be adjusted to achieve desired performance despite manufacturing variations.
3Volume of moving object
If compact form factor is used, then device size is reduced, but parasitic capacitance increases and becomes unwanted
Solution Approach 1:
The patent converts the unwanted parasitic capacitance between the monopole and slot-like antenna structures into a useful capacitive coupling mechanism for feeding the slot antenna. The parasitic capacitance that would normally be harmful is intentionally designed and controlled to serve as the coupling path, transforming a disadvantage into a functional advantage for achieving dual-band operation.
4Adaptability or versatility
If additional structures or parts are introduced to increase bandwidth, then bandwidth is improved, but device complexity and cost increase
Solution Approach 1:
The patent achieves bandwidth extension by integrating the slot-like antenna within the monopole antenna structure rather than adding separate antenna elements. The slot-like antenna is formed by creating a slot within the existing monopole structure, eliminating the need for additional antenna parts while achieving dual-band operation.
Solution Approach 2:
The integrated antenna structure performs multiple functions: the monopole structure provides primary radiation for one band, while simultaneously serving as a feed mechanism through capacitive coupling to excite the slot-like antenna for the second band. This eliminates the need for separate feeding structures and additional components.
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 doubles or triples the frequency bandwidth, enhancing performance and robustness against manufacturing tolerances, while maintaining a compact form factor without introducing new structures, thereby improving operational efficiency.
Implementation Method 1
a slot-like antenna structure adjacent to the monopole-like or loop-like antenna structure and capacitively fed by the monopole-like or loop-like antenna structure
Data Source
AI summary
A multi-antenna structure includes a monopole-like or loop-like antenna structure with an antenna feed configured to connect to electrical circuitry; and a slot-like antenna structure adjacent to the monopole-like or loop-like antenna structure and capacitively fed by the monopole-like or loop-like antenna structure, wherein the monopole-like or loop-like antenna structure and the slot-like antenna structure operate as a combined antenna with extended bandwidth relative to operation individually. The monopole-like or loop-like antenna structure can include a horizontal member and a plurality of vertical members connected to the horizontal member. The slot-like antenna structure can include two parallel horizontal members separated by a slot and a vertical member at one end of the slot connected to each of the two parallel horizontal members separated and another end of the slot is open.