How Satellites Send Internet Signals Using Light Beams

This patent describes a ground system that sends many internet data streams to a satellite using a single optical light beam, allowing the satellite to broadcast radio signals without needing to change their frequency.

What it covers

This patent describes a ground-based system that prepares data to be sent to a satellite using light instead of traditional radio waves. The system uses multiple lasers, each emitting light at a different color (wavelength). Each laser's light is then modulated by an electro-optical modulator (EOM) with a specific radio frequency (RF) signal that already contains data for satellite internet. Crucially, these RF signals are within the exact same frequency range (like the Ka band, 17.7 GHz to 20.2 GHz, as per claim 7) that the satellite will use to broadcast to users. All these modulated light signals are then combined into one powerful optical feeder uplink beam and sent to the satellite. Because the RF frequencies are already correct, the satellite does not need any frequency conversion equipment, as stated in claim 1, simplifying its design.

What it doesn't cover

• —Does not cover satellite systems that use traditional radio frequency (RF) signals for the uplink from the ground station.
• —Does not cover systems where the satellite performs frequency conversion on the received uplink signals before transmitting the downlink beams.
• —Does not cover systems where the optical data signals output by the electro-optical modulators are not within the same RF frequency range as the satellite's downlink beams.
• —Does not cover systems where the service terminals receive optical signals directly, rather than radio frequency (RF) service downlink beams.
• —Does not cover satellites that only transmit a single RF service downlink beam, as the patent specifies a 'plurality' (multiple) of beams.

The clever bit

The truly clever part is that the ground system prepares the data in the exact radio frequency (RF) range that the satellite will use for broadcasting, before sending it up as light. This means the satellite can simply convert the light back into radio waves and transmit them directly, avoiding the need for heavy and power-consuming frequency converters in space.

Why it matters

This technology is important for high-throughput satellites, which are designed to deliver massive amounts of data, often for internet access. By eliminating complex frequency conversion equipment on the satellite itself, it can make satellites lighter, less power-hungry, and potentially more reliable. This efficiency helps provide faster and more affordable satellite internet services to remote areas and for applications like in-flight connectivity.

Real-world examples

• 1.High-throughput satellite internet services
• 2.Satellite communications for remote regions
• 3.In-flight internet connectivity systems
• 4.Maxar Technologies (formerly Space Systems Loral) satellite platforms