Optical Modulator Crosstalk Reduction via High-Resistance Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical modulators face challenges in maintaining good crosstalk characteristics when the distance between differential lines is narrowed, which is necessary for further size reduction.
Innovation Solution
The optical modulator incorporates a configuration with repeatedly arranged isolated high-resistance conductive films between adjacent differential lines, which helps improve crosstalk characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the distance between differential lines is narrowed to reduce size, then the device size is reduced, but the crosstalk characteristics are deteriorated
Solution Approach 1:
The patent introduces a ground electrode as an intermediary element positioned between adjacent differential line pairs. This ground electrode acts as a mediator that shields the signal lines from each other, reducing electromagnetic coupling and crosstalk. The ground electrode is connected to the substrate ground potential, creating a reference plane that isolates the differential pairs electrically while maintaining compact spacing.
Solution Approach 2:
The patent applies different structural characteristics to different regions of the differential line structure. Specifically, the signal lines maintain narrow spacing for size reduction, while the ground electrode is strategically positioned between them to provide localized shielding. This creates a non-uniform structure where the region between lines has enhanced grounding density to counteract the harmful electromagnetic fields in that specific location.
2Volume of moving object
If the distance between differential lines is narrowed to reduce size, then the device size is reduced, but the ripple characteristics are deteriorated
Solution Approach 1:
The ground electrode serves as a stabilizing intermediary that provides a consistent reference potential between adjacent differential lines. By maintaining a stable ground connection in the region between lines, the structure reduces voltage fluctuations and ripple effects that would otherwise be amplified by the narrow spacing. The ground electrode acts as a buffer that absorbs electromagnetic interference and stabilizes the electrical environment.
Solution Approach 2:
The patent enhances the grounding density in the critical region between differential lines while maintaining narrow overall device dimensions. This localized quality enhancement creates a stable electrical reference plane precisely where ripple and interference are most problematic, without requiring the entire device to be enlarged for improved stability.
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 effectively reduces crosstalk by about 10 dB or more in a wide high-frequency region up to 60 GHz, maintaining good crosstalk characteristics even when the distance between differential lines is narrowed.
Implementation Method 1
a plurality of high-resistance conductive films are provided between adjacent high-frequency line pairs separated from the high-frequency line pair
Data Source
AI summary
An optical modulator includes a plurality of optical modulation units having a Mach-Zehnder type optical waveguide consisting of two optical waveguides and a high-frequency line pair arranged along the two optical waveguides and consisting of two signal electrodes for applying a pair of differential high-frequency signals, and a plurality of high-resistance conductive films are provided between adjacent high-frequency line pairs separated from the high-frequency line pair.