Hybrid-Harmonic Waveguide Filter with Shaped Ridge Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-power low-pass filters for space programs are either costly, have low manufacturing yield, and limited power handling due to residual post-etch aluminum, and fail to provide adequate rejection of TEn0 modes in the presence of h-plane bends, which are common in spacecraft assembly.
Innovation Solution
A high-power hybrid-harmonic filter with transformer sections, corrugations, and shaped hybrid-ridge interconnects created via wire electrical-discharge machining, offering a broad passband and continuous broadband TEn0 rejection, while reducing manufacturing costs and increasing power handling by avoiding electroforming and splitting the geometry in a zero-current region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional electroformed waffle iron filter is used, then compact envelope and continuous broadband TEn0 rejection are achieved, but manufacturing cost is high and manufacturing yield is low due to residual post-etch aluminum
Solution Approach 1:
The patent replaces the electroforming process with a mechanical machining process (milling). The waveguide filter structure is manufactured by directly milling the conductor material to create the corrugations and ridges, eliminating the need for electroformed waffle iron construction. This substitution resolves the contradiction by achieving precise TEn0 rejection through mechanical machining while avoiding the manufacturing defects and high costs associated with electroforming.
2Volume of moving object
If traditional waffle filter is used, then compact structure is achieved, but power handling capability is very low
Solution Approach 1:
The patent changes the geometric parameters of the waveguide structure by introducing ridges with specific dimensions and configurations. The ridge height, width, and spacing are optimized to maintain the compact form factor while significantly enhancing the power handling capability. The ridges modify the electromagnetic field distribution to reduce peak current density, allowing the compact structure to handle high power without the limitations of traditional waffle filters.
3Ease of manufacture
If waffle geometry is split to reduce fabrication cost, then manufacturing cost decreases, but splitting must occur on peak current region which is not desirable
Solution Approach 1:
The patent introduces ridges that extend in the longitudinal dimension of the waveguide, creating a three-dimensional structure that redistributes current paths. This dimensional addition allows the filter to be split along the longitudinal axis at locations that avoid peak current regions, enabling cost-effective fabrication while maintaining current distribution integrity. The ridges provide additional current pathways that prevent concentration at split locations.
4Manufacturing precision
If cascaded-style filters with different width waveguide sections are used, then TEn0 mode cutoffs are positioned advantageously, but filters become very long with high mass and achieve no better than 40 dB rejection
Solution Approach 1:
The patent merges multiple functional elements into a single integrated structure. The corrugations and ridges are combined in one continuous waveguide section rather than using separate cascaded stages. This integration achieves superior TEn0 rejection (exceeding 40 dB) in a compact length by creating a unified electromagnetic field control mechanism that eliminates the need for multiple discrete waveguide sections, thereby reducing both filter length and mass.
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 hybrid-harmonic filter achieves ultra-high multipaction threshold and broadband TEn0 rejection, significantly improving power handling and reducing manufacturing costs, with a broad passband and low-cost production, exceeding traditional waffle filter performance by 300 times in power handling and achieving 100 dB rejection.
Implementation Method 1
The ridge interconnects are shaped via wire electrical-discharge machining (EDM) making them a hybrid to the traditional waffle teeth
Data Source
AI summary
A hybrid-harmonic waveguide filter includes transformer sections at end terminals of the harmonic waveguide filter, a number of corrugations along the length of the waveguide filter, and multiple ridge interconnects that couple the corrugations. By shaping the identical-cross-section ridge interconnects via single-pass wire electrical-discharge machining (EDM), low manufacturing cost is achieved along with continuous broadband rejection of TEn0 modes and an extremely high-power handling capability is observed.