Spacecraft Optical Interconnect Analog Biasing for Radiation Immunity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Digital optical interconnect devices in satellite communication payloads are vulnerable to signal integrity degradation and functional interruptions due to radiation exposure, necessitating improved radiation tolerance.
Innovation Solution
The electro-optical device operates integrated circuits in an analog mode with analog voltage settings that are either provided externally, internally, or through hardwired connections, including the use of eFuse, to maintain functionality despite radiation exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If digital optical interconnect devices are used in satellite communication payloads, then operational flexibility and digital payload architecture are improved, but signal integrity and functional reliability deteriorate under radiation exposure
Solution Approach 1:
The patent changes the operating parameters of the integrated circuits from digital mode to analog mode. Specifically, the circuits operate with analog voltage settings (such as bias voltages for photodetectors and lasers) that are determined by physical connections (hardwired, external, or internal) rather than digital control signals. This parameter change makes the communication system resistant to radiation-induced digital errors while maintaining operational flexibility.
Solution Approach 2:
The patent inverts the conventional approach by using analog voltage settings instead of digital control for configuring the integrated circuits. Rather than using digital registers and control logic that are vulnerable to radiation, the configuration is established through physical voltage references and analog circuitry, effectively inverting the control paradigm from digital to analog to achieve radiation hardness.
2Reliability
If analog mode operation is implemented in integrated circuits, then radiation immunity is improved, but device complexity increases due to analog voltage configuration requirements
Solution Approach 1:
The patent segments the voltage configuration into distinct categories: hardwired connections (fixed at manufacture), external connections (configurable via external voltage sources), and internal connections (self-configured within the device). This segmentation allows designers to choose the appropriate level of complexity for their specific application, from simple fixed configurations to more flexible external programming, thereby managing device complexity while maintaining radiation immunity.
Solution Approach 2:
The patent implements self-service through internal voltage references and automatic bias generation circuits that configure themselves without external intervention. The integrated circuits contain internal voltage regulation and bias generation that automatically establish the required analog operating points, eliminating the need for complex external configuration circuitry and reducing overall device complexity.
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 enhances radiation immunity, as demonstrated by Single Event Effect tests showing no functional interrupts even under heavy ion radiation, meeting stringent space operation standards without the need for custom chips.
Implementation Method 1
converting a first electrical signal into a first optical signal and outputting the first optical signal within the spacecraft, and receiving capabilities for receiving a second optical signal within the spacecraft and converting the second optical signal into a second electrical signal
Data Source
Figure 1
Figure 2
Figure 3
AI summary
There are described methods and devices for intra-spacecraft communication in space, the electro-optical device having at least one of transmitting capabilities for converting a first electrical signal into a first optical signal and outputting the first optical signal within a spacecraft, and receiving capabilities for receiving a second optical signal within the spacecraft and converting the second optical signal into a second electrical signal, the electro-optical device having at least one integrated circuit dedicated to at least one of the transmitting capabilities and the receiving capabilities, the at least one integrated circuit configured for operating in an analog mode where configuration voltages for the integrated circuit are provided by analog voltage settings unaffected by radiation.