Antenna Notch Design for Backside Gain Reduction
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Solution Overview
Problem
Conventional antennas face challenges in reducing backside gain to minimize multipath interference while maintaining sensitivity, especially for circularly polarized waves, and existing solutions often compromise frequency characteristics or require design modifications.
Innovation Solution
The antenna design incorporates a plurality of ground conductors with notches outside the radiation conductor area, forming a choke structure with a conductor wall to reduce backside gain while maintaining sensitivity, particularly for circularly polarized waves, by increasing radiation suppression without altering the basic design or frequency characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If notches are provided on the ground conductor plate to raise the F-to-B ratio, then backside gain is reduced, but overall antenna sensitivity is reduced
Solution Approach 1:
The ground conductor plate is segmented into multiple separate ground conductors (first ground conductor and second ground conductor) with a gap between them. The notches are provided only on the first ground conductor, not on the second ground conductor. This segmentation allows the notches to reduce backside gain while the second ground conductor maintains overall antenna sensitivity by providing an alternative current path.
2Object-generated harmful factors
If notches are provided on the ground conductor plate to raise the F-to-B ratio, then backside gain is reduced, but frequency characteristics change
Solution Approach 1:
The ground conductor plate is divided into multiple separate ground conductors, with notches provided only on specific segments (first ground conductor) rather than the entire ground conductor plate. This selective segmentation reduces backside gain while minimizing disruption to the overall current distribution and frequency characteristics of the antenna.
3Object-generated harmful factors
If a choke structure is added to reduce backside gain, then multipath resistance is improved, but device complexity increases
Solution Approach 1:
The choke structure is merged with the ground conductor plate by integrating it into the existing ground conductor configuration. The first and second ground conductors form part of the choke structure while maintaining the overall ground plane functionality. This integration reduces backside gain and improves multipath resistance without significantly increasing device complexity.
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 design effectively reduces backside gain while preserving overall antenna sensitivity, enhancing multipath resistance and maintaining minimal impact on frequency characteristics, thus improving the F-to-B ratio and reducing material costs.
Implementation Method 1
the conductor wall 104 and the ground conductor plates 103a and 103b constitute a choke structure. Since a radio wave entered from behind can be trapped by this choke structure, it is possible to reduce the influence of multipath on the antenna 100.
Implementation Method 2
the notches 203 allow a pathway length of the induction current flowing across the outer circumferential edge to be elongated, out of the induction current induced in the ground conductor plate 204, without preventing a main flow of induction current crossing over the center portion.
Data Source
AI summary
It is an object of the present invention to provide an antenna capable of reducing a backside gain while keeping the sensitivity of overall antenna to a certain level. Particularly, in the case of an antenna subject to a circularly polarized wave, it is an object of the invention to provide an antenna capable of reducing the sensitivity of a left-handed circularly polarized wave more than ever before as well as keeping the sensitivity of a right-handed circularly polarized wave to a certain level. The antenna of the invention includes a plurality of ground conductors, a radiation conductor provided via a dielectric on a part of the above-mentioned ground conductor. The notch is formed on at least one of the above-mentioned ground conductors. The notch is formed outside of the area opposite to the above-mentioned radiation conductor.