Post-Wall Waveguide to Microstrip Mode Converter With Anti-Pads
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Solution Overview
Problem
Mode converters for millimeter-wave bands experience increased return loss when using existing configurations for mutual conversion between post-wall waveguide and microstrip line modes.
Innovation Solution
Incorporating ring-like anti-pads on the conductor layers surrounding the excitation pin, with an outer size between 5 and 6 times the diameter of the pin, to reduce return loss in the mode converter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing mode converter configuration is used for millimeter-wave band operation, then the basic waveguide mode conversion function is achieved, but return loss increases
Solution Approach 1:
The patent applies parameter changes by optimizing the anti-pad outer size to a specific range (5-6 times the excitation pin diameter) and adjusting the excitation pin diameter (0.2-0.5 times the post-wall waveguide width). These parameter modifications directly address the high return loss issue in millimeter-wave band operation while maintaining manufacturability through clearly defined dimensional relationships.
2Reliability
If anti-pad size is increased to reduce return loss, then conversion efficiency improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent defines specific parameter ranges for anti-pad outer size (5-6 times the excitation pin diameter) and excitation pin diameter (0.2-0.5 times the post-wall waveguide width). These standardized parameter relationships improve conversion efficiency while providing clear manufacturing guidelines that balance performance with fabrication capabilities.
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 configuration effectively reduces return loss in mode converters operating within millimeter-wave bands by optimizing the anti-pad sizes and shapes, enhancing conversion efficiency.
Implementation Method 1
an excitation pin made of a through via which penetrates through the post-wall waveguide, the excitation pin being configured to carry out mutual conversion between a waveguide mode of the post-wall waveguide and a waveguide mode of the microstrip line
Implementation Method 2
the first anti-pad and the second anti-pad each having a ring-like shape and each being formed so as to (i) have an inner edge including the excitation pin and (ii) have an outer size that is more than 5 times and less than 6 times as large as a diameter of the excitation pin
Data Source
AI summary
An aspect of the present invention is to reduce return loss in a mode converter. A mode converter (10) includes an excitation pin (through via TV) configured to carry out mutual conversion between a waveguide mode of a post-wall waveguide (PW) and a waveguide mode of a microstrip line (MS). The mode conductor includes a pair of wide walls (conductor layers 12 and 13), in which first and second anti-pads (anti-pads 12c, 13c) are formed, respectively. The first and second anti-pads each have an inner edge including the excitation pin and each have an outer size (diameter D12) that is more than 5 times and less than 6 times as large as the diameter (DT) of the excitation pin.