Photonic Switch for Rapid Beam Hopping in Satellite Systems
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Solution Overview
Problem
Wireless communication systems, such as satellite communication systems, face challenges in efficiently sharing a common access node and distributing signals to multiple outputs without simultaneous time usage, particularly in implementing satellite beam hopping, which requires rapid and power-efficient switching mechanisms.
Innovation Solution
The implementation of photonic switch devices that convert data modulated RF signals to optical signals using tunable lasers and wavelength division multiplexing (WDM) for switching, allowing for rapid beam hopping and power reduction by enabling multiple beams to share limited power resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional electrical switching is used for beam hopping, then the system can distribute signals to multiple outputs, but the switching speed is slow and power consumption is high
Solution Approach 1:
The patent replaces traditional electrical switching mechanisms with photonic switching using tunable lasers and optical modulators. The tunable laser generates optical signals at different wavelengths, and the optical modulator modulates the RF signal onto the optical carrier. This substitution of electrical switching with optical switching enables much faster switching speeds and lower power consumption, as optical switching operates at the speed of light and consumes less energy than electrical switching.
Solution Approach 2:
The patent changes the switching parameter from electrical voltage/current to optical wavelength. By tuning the laser wavelength to select different output channels, the system achieves rapid switching without the delays inherent in electrical switching. The wavelength tuning mechanism allows for fast reconfiguration of signal distribution paths, directly addressing the speed requirement while the optical domain operation reduces power consumption.
2Productivity
If multiple beams share common access node simultaneously, then system capacity increases, but power resources become insufficient for all beams
Solution Approach 1:
The patent implements periodic time-division multiplexing where multiple beams share the common access node in sequential time slots rather than simultaneously. The tunable laser and optical switch are controlled to direct signals to different output beams in alternating time periods. This periodic switching allows multiple beams to access the shared resource without collision, increasing overall system capacity while ensuring each beam receives adequate power during its allocated time slot.
Solution Approach 2:
The patent segments the time domain to allow multiple beams to share the common access node. By dividing the transmission time into discrete slots and assigning different beams to different slots, the system enables multiple users to access the shared resource without interference. This temporal segmentation increases the effective system capacity by allowing N beams to utilize the common node N times over a period, while power resources are allocated efficiently through this time-shared approach.
3Adaptability or versatility
If rapid beam hopping is implemented, then signal distribution flexibility improves, but switching latency increases
Solution Approach 1:
The patent replaces electrical switching with optical switching using tunable lasers and optical modulators. Optical switching operates at the speed of light and can reconfigure signal paths much faster than electrical switching. The tunable laser can rapidly change wavelengths to select different output channels, and the optical modulator can quickly modulate signals onto the optical carrier. This substitution eliminates the latency inherent in electrical switching while maintaining the flexibility to distribute signals to any combination of outputs.
Solution Approach 2:
The patent implements preliminary configuration of the tunable laser and optical switch before signal transmission. The laser is pre-tuned to the required wavelength, and the optical switch is pre-positioned to direct signals to the correct output channel. This preliminary setup eliminates the need for complex real-time switching calculations and reduces the effective latency by having the switching infrastructure ready in advance. The system can rapidly adapt to different signal distribution requirements by simply changing the pre-configured parameters rather than performing complex switching operations during transmission.
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
Enables efficient switching and power reduction in wireless communication systems by allowing rapid beam hopping and simultaneous sharing of power among geographically dispersed beams, improving system performance and reducing latency.
Implementation Method 1
a tunable laser, a controller, an electro-optical modulator (EOM), a wavelength-division multiplexing (WDM) demultiplexer
Implementation Method 2
electro-optical modulating an optical signal produced using the tunable laser with the accepted data modulated RF signal
Implementation Method 3
wavelength-division multiplexing (WDM) for switching, allowing for rapid beam hopping
Implementation Method 4
N photodetectors (PDs)... each of the N PDs is optically coupled to a respective one of the N outputs
Data Source
AI summary
A photonic switch device accepts a data modulated RF signal and outputs the data modulated RF signal or a frequency converted version thereof at one or more outputs of the switch device. Tunable laser(s) is/are controlled to cause peak wavelength(s) of the optical signal(s) emitted therefrom. An EOM receives the accepted data modulated RF signal and optical signal(s) produced using the tunable laser(s), and the EOM outputs an optical data signal modulated to include the data modulated RF signal. A WDM receives the optical data signal output by the EOM and the optical data signal received by the WDM demultiplexer is output at one or more outputs thereof based on peak wavelength(s) of the optical data signal. Photodetectors optically coupled to respective outputs of the WDM demultiplexer convert optical signals back to electrical signals. Related methods and system are also described herein.