The Concept 

The Starlink fleet is composed of over 5000 satellites in low Earth orbit. Ground stations, called gateways, are distributed around the globe and send data up to the satellites using microwaves. The satellites then relay the data to users, who each have a dedicated user terminal to receive their data.  As user traffic on the network increases over time, we must turn to higher frequency microwaves to ensure adequate bandwidth. This requires development of new microwave amplifiers designed to work at the higher frequency ranges.

My Work

I lead a team of RF engineers who run electrostatic, magnetic, and particle tracking simulations to design the next generation of Traveling Wave Tube Amplifiers (TWTAs). These amplifiers use a focused electron beam to amplify a low power microwave input signal. The high power microwave output allows for transmission of data over long distances—through the atmosphere to a satellite, for example. 

Our effort focuses on developing TWTAs at E-band (80 GHz) and above. This is a significant advance over prior mass-produced TWTAs, which focused on lower frequency bands (below 30 GHz) that are insufficient for today's applications. Mechanical and electron beam dimensions within the TWTA scale inversely with frequency, making these high frequency devices very challenging to fabricate. Advanced modeling, measurement, and fabrication strategies have enabled our success.

Prior to leading the team, I designed the beam optics for all prototype and currently-deployed SpaceX TWTAs. During the testing phase, I developed and operated RF and high voltage test setups to assess device performance. I also worked closely with mechanical, power, software, and networking teams to successfully integrate the TWTA into the SpaceX network.