Post-Wall Waveguide Short Slot Directional Coupler
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing short slot directional couplers face difficulties in fabrication due to the need for high fabrication accuracy and the use of reflection suppressing posts, especially in the microwave and millimeter wave bands, making them costly and challenging to produce.
Innovation Solution
A short slot directional coupler design using post-wall waveguides with via-hole strings arranged in a multi-stepped form, where the distance between via-hole strings varies along their length, eliminating the need for reflection suppressing posts by adjusting the via-hole interval to suppress reflections effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reflection suppressing posts are used to suppress reflections, then reflection suppression is improved, but fabrication accuracy requirements increase and manufacturing difficulty increases
Solution Approach 1:
The invention removes the reflection suppressing posts from the coupling region, extracting the problematic element that caused fabrication difficulties. Instead of using posts, the patent uses a different structural approach with multi-stepped waveguide configurations to achieve reflection suppression without requiring high precision post placement
Solution Approach 2:
The patent changes the geometric parameters of the waveguide structure by implementing multi-stepped width variations and adjusting the spacing between via-hole strings. These parameter changes enable reflection suppression through structural design rather than requiring precisely positioned posts
2Reliability
If multi-stepped waveguide structure is used to achieve wide-banded reflection characteristic, then reflection characteristic is improved, but device complexity and fabrication difficulty increase
Solution Approach 1:
The waveguide structure is segmented into multiple sections with different width steps. Each segment contributes to the overall reflection characteristic, allowing the system to achieve wide-banded performance through distributed segmentation rather than a single complex structure
Solution Approach 2:
The multi-stepped waveguide structure serves multiple functions: it provides reflection suppression, enables wide bandwidth operation, and maintains compatibility with standard PCB fabrication techniques. The via-hole strings simultaneously form the waveguide walls and provide grounding
3Object-affected harmful factors
If via-hole interval is reduced to prevent radio wave leakage, then leakage prevention is improved, but fabrication accuracy requirements increase
Solution Approach 1:
The patent optimizes the via-hole interval parameters to achieve an effective balance between leakage prevention and fabrication tolerability. By carefully selecting the interval distance based on wavelength considerations, the design prevents significant leakage while remaining manufacturable with standard tolerances
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 design allows for easy and cost-effective fabrication of high-frequency circuits by preventing radio wave leakage and suppressing reflections without requiring high fabrication accuracy, enabling efficient operation in microwave and millimeter-wave bands.
Implementation Method 1
a first via-hole string and a second via-hole string, each of which has via-holes penetrating through the substrate, and formed so that a distance between the first via-hole string and the second via-hole string is narrow at a center the string along a length direction thereof
Implementation Method 2
both surfaces each covered by a metal film
Data Source
AI summary
A short slot directional coupler includes a dielectric substrate having both surfaces each covered by a metal film, a first via-hole string and a second via-hole string, each of which has via-holes penetrating through the substrate, and formed so that a distance between the first via-hole string and the second via-hole string is narrow at a center of a length direction of the string and wider along directions of both ends of the string, and a pair of third via-hole strings each having via-holes penetrating through the substrate, and formed between parts adjacent to both ends of the first via-hole string and parts adjacent to both ends of the second via-hole string to form a first post-wall waveguide along with the first via-hole string and a second post-wall waveguide along with the second via-hole string.