Photodefinable Glass-Ceramic RF Transmission Line
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Solution Overview
Problem
Current RF transmission line technologies face challenges in achieving compact, low-loss designs with effective impedance matching, particularly for RF devices on the same substrate, as they often require expensive equipment and result in high insertion losses, making them unsuitable for commercial cellular communication markets.
Innovation Solution
A method involving a photosensitive glass substrate is used to create a mechanically stabilized RF transmission line with a ceramic/glass support pedestal, where the substrate is masked, exposed to an energy source, heated, and etched to form trenches and a mechanical support, allowing for the deposition of metal conductive lines with minimal loss tangent mechanical support, reducing contact area and maintaining low insertion loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional RF transmission line technologies are used, then impedance matching can be achieved, but insertion loss is high and the design is not compact
Solution Approach 1:
The patent changes the material parameter from traditional PCB or ceramic substrates to photodefinable glass-ceramic composite substrate, which has superior electrical and mechanical properties. This material parameter change enables lower insertion loss while maintaining compact design through the substrate's inherent low loss tangent and high mechanical stability
Solution Approach 2:
The patent uses a glass-ceramic composite substrate that combines the low loss properties of glass with the mechanical strength and thermal stability of ceramic. This composite material approach resolves the contradiction by providing a substrate that simultaneously reduces insertion loss and enables compact, stable transmission line structures
2Stability of the object's composition
If mechanical support is increased to stabilize the transmission line, then mechanical stability improves, but contact area increases causing higher loss
Solution Approach 1:
The patent applies local quality by providing mechanical support only where absolutely necessary - using discrete support pedestals or posts at specific locations along the transmission line rather than continuous support. This localized support approach maintains mechanical stability while minimizing the contact area between the transmission line and substrate, thereby reducing insertion loss
Solution Approach 2:
The patent segments the mechanical support into discrete elements (support pedestals or posts) rather than using continuous support. This segmentation allows the transmission line to be mechanically stable at critical points while maintaining air gaps or minimal contact over most of its length, reducing overall insertion loss
3Volume of moving object
If compact design is implemented, then device size is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent replaces traditional mechanical fabrication methods with photodefinition and direct laser writing techniques. These optical-based manufacturing methods enable precise definition of transmission line geometries and features directly on the glass-ceramic substrate, achieving the required manufacturing precision for compact designs through non-mechanical, light-based processing
Solution Approach 2:
The patent changes the manufacturing approach from mechanical machining to photodefinition and laser writing, which offer superior precision control. These parameter changes in the manufacturing process enable the fabrication of compact transmission lines with tight tolerances, resolving the contradiction between small size and manufacturing precision
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 approach enables the fabrication of compact, low-loss RF transmission lines and filters with reduced insertion loss, suitable for RF communication systems, using cost-effective first-generation semiconductor equipment and photodefinable glass ceramic substrates, achieving efficient impedance matching and mechanical stabilization.
Implementation Method 1
heating the photosensitive glass substrate for at least ten minutes above its glass transition temperature; cooling the photosensitive glass substrate to transform at least part of the exposed glass into a glass-crystalline substrate
Implementation Method 2
etching the glass-crystalline substrate with an etchant solution to form one or more trenches and a mechanical support under the design layout
Implementation Method 3
printing or depositing one or more metals or metallic media that form the one or more electrical conductive transmission lines
Data Source
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AI summary
The present invention includes a method of creating electrical air gap or other low loss low cost RF mechanically and thermally stabilized interdigitated resonate filter in photo definable glass ceramic substrate. A ground plane may be used to adjacent to or below the RF filter in order to prevent parasitic electronic signals, RF signals, differential voltage build up and floating grounds from disrupting and degrading the performance of isolated electronic devices by the fabrication of electrical isolation and ground plane structures on a photo-definable glass substrate.