RF Device Impedance Unit for Crosstalk Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radio frequency devices face challenges in efficiently suppressing electromagnetic interference (EMI) due to crosstalk and radiation power, with manual placement of absorbers being time-consuming, laborious, and costly, and prone to human error, especially in small-sized devices.
Innovation Solution
Incorporating an impedance unit, realized by a resistor and optionally a capacitor, between signal ends on the isolation substrate to act as a transmission line terminal, which grounds energy and reduces radiation power, eliminating the need for costly absorbers and manual placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If absorbers are manually pasted onto open stubs for suppressing EMI, then crosstalk and radiation power suppression is achieved, but manufacturing time and labor cost increase significantly
Solution Approach 1:
The invention extracts the EMI suppression function from the manual absorber pasting process and integrates it directly into the PCB manufacturing process through photoresist patterns. The photoresist is applied as a coating that is subsequently developed and etched, automatically forming the suppression structures during standard PCB fabrication without requiring separate manual intervention.
Solution Approach 2:
The invention replaces the mechanical manual pasting operation with a photochemical process. Instead of physically applying absorber materials by hand, the system uses photolithography techniques where light exposure triggers chemical changes in the photoresist, enabling automated pattern formation that defines the EMI suppression structures.
2Object-affected harmful factors
If absorbers are manually placed on small-sized devices, then EMI suppression is achieved, but positioning accuracy deteriorates due to human error
Solution Approach 1:
The invention replaces manual mechanical placement with an automated photochemical patterning process. The photoresist coating method uses precise light exposure through masks or direct digital writing to define patterns with micrometer-level accuracy, eliminating human positioning errors and ensuring consistent placement of EMI suppression structures.
Solution Approach 2:
The photoresist material itself performs the positioning function through its chemical properties. During the development process, the photoresist automatically forms precise patterns based on light exposure, with the material's own characteristics (resolution, adhesion, etch selectivity) ensuring accurate positioning without requiring external alignment tools or manual adjustment.
3Object-affected harmful factors
If multiple absorbers are used for EMI suppression, then crosstalk reduction is improved, but production cost increases due to expensive absorber materials
Solution Approach 1:
The invention replaces expensive specialized absorber materials with inexpensive photoresist, a standard PCB manufacturing material. The photoresist is applied as a thin coating that is subsequently removed after serving its patterning function, leaving behind the etched EMI suppression structures. This approach uses cheap, readily available materials to achieve the same functional result.
Solution Approach 2:
The photoresist serves multiple functions: it acts as the EMI suppression material, the patterning medium for defining structures, and the etch mask for creating the final geometry. This multi-functionality eliminates the need for separate expensive absorber materials and reduces the overall bill of materials cost while maintaining effective EMI suppression.
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 solution effectively suppresses EMI and crosstalk interference, reducing manufacturing costs and time, while providing stable circuit characteristics through surface mount technology, with improved radiation power suppression and reflection parameter distribution.
Implementation Method 1
an impedance unit, realized by a resistor and optionally a capacitor, between signal ends on the isolation substrate to act as a transmission line terminal, which grounds energy and reduces radiation power
Data Source
AI summary
A radio frequency device is disclosed, which includes an isolation substrate, a ground layer, a first signal end, a second signal end, a radio frequency circuit, and an impedance unit. The isolation substrate includes a first plane and a second plane. The ground layer is disposed on the second plane of the isolation substrate for providing grounding. The first signal end is formed on the first plane of the isolation substrate. The second signal end is formed on the first plane of the isolation substrate and coupled to the ground layer. The radio frequency circuit is disposed on the first plane of the isolation substrate and coupled to the first signal end. The impedance unit is disposed on the first plane of the isolation substrate and coupled to the first signal end and the second signal end.