Optical Receiver Package Feed-Through Noise Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As optical communication transmission speeds increase, electromagnetic noise from wiring between the driving circuit and the optical transmitter module generates crosstalk in adjacent optical receiver modules due to the proximity of these components, with conventional optical receiver module packages failing to effectively mitigate this noise through their dielectric feed-throughs.
Innovation Solution
The package for the optical receiver module incorporates a conductive housing with a feed-through that includes a ground layer and a shield layer with parasitic capacitance, where DC lines are connected to the shield layer via via-holes, and electromagnetic shielding wirings are placed adjacent to transmission lines to create small current loops that cancel out noise, reducing electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dielectric feed-through is used to establish electric continuity between inside and outside of the housing, then electrical connection is achieved, but electromagnetic noise easily enters the housing through the wirings
Solution Approach 1:
The patent introduces a ground layer as an intermediary between the signal wirings and the housing interior. This ground layer acts as a mediator that provides a controlled impedance path and shields the sensitive optical receiver components from electromagnetic noise carried by the power supply wirings through the feed-through.
Solution Approach 2:
The patent converts the potentially harmful electromagnetic noise carried by the power supply wirings into a beneficial shielding effect by introducing electromagnetic shielding wirings adjacent to the transmission lines. These shielding wirings create small current loops that generate opposing magnetic fields to cancel out the noise, transforming the noise pathway into a protective mechanism.
2Volume of moving object
If optical transmitter module and optical receiver module are disposed adjacent to each other for miniaturization, then space efficiency is improved, but electromagnetic noise causes crosstalk in the receiver module
Solution Approach 1:
The patent applies local quality by providing electromagnetic shielding specifically at the feed-through location where power supply wirings enter the housing. The ground layer and shielding wirings are strategically positioned adjacent to the transmission lines only where needed to block noise from entering the housing, rather than providing universal shielding throughout the entire structure.
Solution Approach 2:
The patent converts the proximity-induced noise coupling into a protective effect by using the shielding wirings to create controlled current loops. These loops generate magnetic fields that oppose and cancel the noise fields from adjacent transmission lines, transforming the harmful close proximity into an opportunity for active noise cancellation.
3Object-affected harmful factors
If ground layer and shield layer with parasitic capacitance are added to the feed-through, then electromagnetic noise is attenuated, but device complexity increases
Solution Approach 1:
The patent merges the ground layer and shield layer functions into a single integrated feed-through structure. The ground layer is incorporated as part of the feed-through assembly itself, and the shielding wirings are positioned adjacent to the transmission lines within the same feed-through housing, combining multiple shielding functions into one unified component rather than separate additions.
Solution Approach 2:
The patent utilizes parasitic capacitance as an intentional design parameter rather than trying to eliminate it. By accepting and leveraging the inherent parasitic capacitance of the feed-through structure, the patent creates beneficial current loops that attenuate high-frequency noise without requiring additional complex filtering components or structures.
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 configuration significantly attenuates electromagnetic noise, thereby reducing crosstalk and improving the reception performance of the optical receiver module by effectively canceling out noise currents and securing wide spaces for wirings.
Implementation Method 1
a feed-through provided in the rear wall of the housing. The feed-through includes an internal portion having an upper rear face and a lower rear face, the internal portion being made of an insulating material, and an external portion made of the insulating material, the external portion protruding from the upper rear face and the lower rear face of the internal portion outwardly
Implementation Method 2
electromagnetic shielding wirings are placed adjacent to transmission lines to create small current loops that cancel out noise
Implementation Method 3
DC lines are connected to the shield layer via via-holes, and electromagnetic shielding wirings are placed adjacent to transmission lines to create small current loops that cancel out noise
Data Source
AI summary
A package for an optical receiver module is disclosed. The package includes a housing having electrically conductive walls including a rear wall and a pair of side walls, and a feed-through provided in the rear wall. The feed-through includes an internal portion having an upper rear face and a lower rear face, and an external portion protruding from the upper rear face and the lower rear face outwardly and having a top face and/or a back face continuous to the upper rear face and/or the lower rear face of the internal portion, a first top face, a second back face, and a pair of side faces, the rear face and the side faces connecting the first top face with the second back face, the first top face including DC lines, the second back face including transmission lines, and the transmission lines.