Monolithic Microwave Switch Array Plasma Confinement
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Solution Overview
Problem
Prior art semiconductor microwave switches suffer from plasma diffusion issues, where the plasma created by each PIN junction switch is not effectively confined, leading to performance degradation of individual switches and the entire array, due to contamination and diffusion along the slotline.
Innovation Solution
The proposed solution involves a monolithic array of semiconductor microwave switches with secondary PIN junctions and electrodes that localize the plasma injection to the area between primary electrodes, using secondary electrodes to efficiently collect and extract the plasma through the drift phenomenon, minimizing diffusion and maintaining switch performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasma is injected into the passivation region to close the switch, then the switch achieves the closed state, but the plasma diffuses away from the electrodes along the slotline, degrading switch performance
Solution Approach 1:
The patent extracts the harmful plasma diffusion effect by introducing a plasma barrier region that actively prevents plasma from diffusing along the slotline. The barrier region is positioned to intercept and contain the plasma within the switching area, effectively removing the harmful diffusion effect from the system.
Solution Approach 2:
The plasma barrier region acts as an intermediary structure between the PIN junction and the slotline. It mediates the plasma behavior by providing a controlled path that confines plasma to the desired switching area while preventing it from contaminating other switches and degrading performance.
2Reliability
If plasma is injected into the passivation region, then the switch closes, but the plasma contaminates other switches and slotlines in the array, degrading overall array performance
Solution Approach 1:
The patent segments the plasma confinement function by introducing a dedicated plasma barrier region for each switch. This segmentation isolates the plasma from each PIN junction to its own designated area, preventing cross-contamination between adjacent switches in the array and maintaining overall array performance.
Solution Approach 2:
The plasma barrier region provides localized plasma management at each switch position. By creating a locally tailored barrier structure, the patent ensures that plasma is confined to the specific switching area without affecting neighboring switches, thereby maintaining local and overall array performance.
3Ease of manufacture
If the switch array uses conventional PIN junctions, then manufacturing is simplified, but plasma diffusion cannot be controlled, leading to performance degradation
Solution Approach 1:
The patent merges the plasma confinement function with the existing PIN junction structure by integrating the plasma barrier region into the monolithic semiconductor substrate. This combination maintains the simplicity of conventional manufacturing processes while adding the necessary plasma control capability to prevent performance degradation.
Solution Approach 2:
The patent modifies the substrate structure by creating a plasma barrier region with different electrical properties (higher doping concentration) compared to the surrounding substrate. This parameter change enables plasma confinement without fundamentally altering the manufacturing process, as it can be achieved through standard diffusion or ion implantation techniques.
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 effectively confines the plasma to the desired switching area, reducing performance degradation and interference between switches, enabling precise operation of the array for applications like beam-shaping antennas.
Implementation Method 1
an electron-hole plasma (not shown) is created and injected into the passivation region 22 between the electrodes 14, 16, thereby shorting the electrodes
Implementation Method 2
evanescent coupling between the transmission line and the antenna element when an electromagnetic signal is transmitted through the transmission line, electromagnetic radiation is transmitted or received by the antenna
Implementation Method 3
secondary electrodes to efficiently collect and extract the plasma through the drift phenomenon, minimizing diffusion
Data Source
Figure 1
Figure 2~5
Figure 6
AI summary
A microwave switch array includes a plurality of microwave slotlines, each of which is controlled by a semiconductor switch including a first PIN junction formed by a primary P-type electrode and a primary N-type electrode separated by the slotline. The switches inject a plasma into the slotline in response to a potential applied across the first PIN junction. Each of the switches includes a second PIN junction between the primary P-type electrode and a secondary N-type electrode, and a third PIN junction between the primary N-type electrode and a secondary P-type electrode. Metal contacts connect the primary P-type electrode and the secondary N-type electrode across second PIN junction, and the primary N-type electrode and the secondary P-type electrode across the third PIN junction. The secondary electrodes extract plasma that diffuses away from the first PIN junction, thereby minimizing the performance degrading effects of plasma diffusion.