Electro-optical modulator with ground electrode shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electro-optical modulators suffer from cross-talk between signal lines, require significant space for high on-chip device density, experience signal losses due to insufficient electromagnetic shielding, and have high fabrication costs, especially when operating at high data transmission rates.
Innovation Solution
An electro-optical modulator design featuring a novel transmission line configuration with adjacent electrodes and a co-planar architecture, utilizing a semiconductor arrangement with pn-diodes or semiconductor-insulator-semiconductor capacitors, and incorporating electrode extensions to reduce RF losses and cross-talk, allowing for compact geometry and efficient shielding with a single metallization layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional push-pull configuration is used to achieve high data transmission rates, then data transmission capability is improved, but cross-talk between neighbouring signal lines occurs
Solution Approach 1:
The patent introduces a ground electrode as an intermediary element positioned between the signal lines in the push-pull configuration. This ground electrode acts as a mediator that provides electromagnetic shielding and reduces cross-talk between the neighbouring signal lines while allowing the high data transmission rate capability to be maintained
Solution Approach 2:
The patent applies different electrical potentials to different regions of the electrode structure. The ground electrode is held at a reference potential while the signal lines carry high-frequency signals, creating local electrical field confinement that reduces cross-talk in specific regions while maintaining overall system performance
2Object-generated harmful factors
If sufficient distance is provided between signal lines to limit cross-talk, then cross-talk is reduced, but on-chip device density decreases
Solution Approach 1:
The patent moves the shielding function from the lateral dimension (increasing distance between signal lines) to the vertical dimension by introducing ground electrodes positioned above and below the signal lines. This allows signal lines to be closely spaced in the lateral direction while still achieving cross-talk reduction through vertical electromagnetic shielding
Solution Approach 2:
The ground electrodes serve as intermediary structures that enable close spacing of signal lines by providing electromagnetic isolation. These intermediaries allow high device density while maintaining signal integrity through controlled electromagnetic field management
3Loss of energy
If complex electro-magnetic shielding provisions are implemented to reduce signal losses, then transmission line losses are reduced, but fabrication costs increase
Solution Approach 1:
The patent combines the ground electrode functions into a single integrated structure that provides electromagnetic shielding for multiple signal lines simultaneously. This merged shielding approach reduces signal losses effectively while requiring fewer discrete components and simpler fabrication processes compared to individual shielding for each signal line
Solution Approach 2:
The ground electrodes serve multiple functions: they provide electromagnetic shielding to reduce signal losses, act as reference potential planes for impedance control, and serve as thermal management paths. This multi-functionality reduces the need for separate dedicated shielding structures, lowering fabrication complexity and cost
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 solution effectively suppresses cross-talk, enables high on-chip device density, reduces transmission line losses, and lowers fabrication costs by maintaining high-frequency operation with efficient shielding and compact geometry, suitable for high data rate applications.
Implementation Method 1
electro-optical modulator based on carrier depletion or carrier accumulation in pn-diodes or in semiconductor-insulator-semiconductor capacitors
Implementation Method 2
electro-optical modulator based on carrier depletion or carrier accumulation in pn-diodes or in semiconductor-insulator-semiconductor capacitors
Implementation Method 3
electro-optical modulator
Data Source
Figure 1~2b
Figure 3~5
Figure 6~7
AI summary
An electro-optical modulator (1) is proposed to have two electrodes (33, 35) being part of a transmission line (19) of a first phase modulator and further two electrodes (37, 39) being part of a transmission line (19) of a second phase modulator included in two arm of a Mach-Zehnder-interferometer. Each transmission line (19) comprises a pn-diode (41, 43) or a semiconductor-isolator-semiconductor capacitor. Furthermore, an electrical controller (17) is adapted for applying first electrical high-frequency-modulated voltage signals Sig1(t) between the first and second electrodes (33, 35) and for applying second electrical high-frequency-modulated signals Sig2(t) between the fourth and third electrodes (39, 37). However, a DC component of these signals Sig1(t) and Sig2(t) and a polarity with which these signals are applied to the first and second diodes (41, 43) or to the first and second semiconductor-insulator-semiconductor capacitor principally differ in comparison to conventional approaches in that the electrical controller (17) shall apply signals such that voltages applied to the first and fourth electrodes (33, 39) have substantially a same high-frequency content, and the voltages applied to the second and third electrodes (35, 37) have substantially the same high-frequency content. In such configuration, either the voltages applied to the first and fourth electrodes (33, 39) differ by a constant voltage offset, or, alternatively, the voltages applied to the second and third electrodes (35, 37) differ by a constant voltage offset. Thereby, cross-talk between electrodes and electrical losses as well as device size and fabrication costs may be reduced.