Balanced Antenna with Infinite Baluns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electrically small antennas face performance issues due to the effects of coaxial cables, including impedance matching, radiation pattern, noise rejection, and stability, which are exacerbated by the cable's routing and connection to the radio transceiver.
Innovation Solution
A balanced antenna system with planar conductors, infinite baluns, and non-conductive support is designed to minimize the impact of coaxial cables by canceling RF currents on the cable and maintaining symmetry, reducing RF currents on the cable and improving noise rejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a coaxial cable is used to connect the antenna to the radio transceiver, then the antenna can be placed in a more convenient position and isolated from the PCB, but the cable introduces harmful stray currents that affect impedance matching, radiation pattern, and noise rejection
Solution Approach 1:
The patent uses the coaxial cable's outer conductor, which normally carries harmful stray currents, as part of the balanced antenna structure itself. By incorporating the cable into the radiating element design, the previously harmful currents become useful radiating currents, eliminating the contradiction between cable connectivity and harmful interference.
Solution Approach 2:
The patent merges the coaxial cable with the antenna structure by using the cable's outer conductor as one of the balanced antenna elements. This integration eliminates the separation between cable and antenna that normally causes stray current problems, while maintaining the positioning flexibility benefits of using a cable.
2Volume of moving object
If the antenna is electrically small, then the device size is reduced, but the cable's effect on the antenna becomes significantly more pronounced
Solution Approach 1:
For electrically small antennas where cable effects are magnified, the patent converts the cable from a source of harm into an integral part of the radiating structure. This eliminates the disproportionate cable interference that normally plagues compact antenna designs.
Solution Approach 2:
The patent combines the cable and antenna into a single integrated structure, eliminating the harmful interactions that become particularly problematic in electrically small antenna designs. The cable is no longer an external element causing interference but becomes part of the controlled antenna system.
3Object-generated harmful factors
If traditional baluns or choke structures are used to reduce cable effects, then cable stray currents are suppressed, but the device complexity and size increase
Solution Approach 1:
The patent eliminates the need for separate balun or choke structures by merging the cable directly into the antenna design. The balanced-to-unbalanced transformation is achieved through the geometric configuration of the integrated structure rather than through additional suppression components.
Solution Approach 2:
The coaxial cable serves multiple functions simultaneously: it provides the unbalanced feed connection, acts as one of the balanced radiating elements, and eliminates the need for separate balun components. This multi-functionality reduces overall device complexity while achieving cable effect suppression.
4Reliability
If the cable routing is changed to improve antenna performance, then radiation pattern and impedance matching improve, but the manufacturing precision and assembly difficulty increase
Solution Approach 1:
The patent merges the cable routing into the antenna's fixed geometric structure, eliminating the need for separate cable routing adjustments. The cable follows a predetermined path that is integral to the antenna design, ensuring consistent performance without requiring high manufacturing precision for cable placement.
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 significantly reduces radiation from the cable, enhances noise rejection, and stabilizes antenna performance across a wide frequency range, independent of cable length and routing, while maintaining compact size and cost-effectiveness.
Implementation Method 1
The infinite baluns transform the unbalanced transmission line characteristic of the coaxial cable to the balanced feeding of the antenna; at the same time, the return currents cancel each-other at position where the external shielding of the coaxial cable is connected to the antenna
Data Source
AI summary
A balance antenna is disclosed herein. The balanced antenna comprises a first planar conductor layer forming an first infinite balun, a second planar conductor layer forming a second infinite balun, and a feeding gap. A cable transports a radio signal from the antenna to a radio and from a radio to the antenna. The first infinite balun and the second infinite balun transform an unbalanced transmission line characteristic of the cable to the balanced feeding of the antenna.