How Does Starlink's Phased Array Antenna Track Satellites Without Moving?

[mfb]

TL;DR

Disassembly of a phased array antenna for Starlink

Starlink has begun its public beta phase, and naturally some people were more interested in the electronics than in fast internet access.

Here is a video how the satellite receiver looks inside. The first half is focused on the mechanical side, the second half is looking at the electronics.
It is a phased array antenna, i.e. hundreds of small antennas that need to be synchronized with picosecond precision. By adjust the delay between the antennas the overall device can track satellites across the sky without moving mechanically.

 

[Spinnor]

https://patents.google.com/patent/US10770790B1/en

Abstract

A phased array antenna system configured for communication with a satellite that emits or receives radio frequency (RF) signals and has a repeating ground track in a first direction, the antenna system includes a phased array antenna including a plurality of antenna elements distributed in a plurality of M columns oriented in the first direction and a plurality of N rows extending in a second direction normal to the first direction, and a plurality of fixed phase shifters aligned for phase offsets between antenna elements in the first direction and a gain-enhancement system configured for gain enhancement in the second direction of radio frequency signals received by and emitted from the phased array antenna.

pdf of patent, https://patentimages.storage.googleapis.com/f2/d3/89/e2fec3d1703a51/US10770790.pdf

 

[anorlunda]

It's remarkable that they can sell it for only $499.

 

[mfb]

It's quite likely that they sell it at a loss. Businessinsider claims to have sources that SpaceX bought 1 million terminals for $2400 each from STMicroelectronics. I don't know how reliable that is, but "more than $500" is very plausible. If the $2400 number is true then SpaceX will need to sell ~1.5 years of $100/month service just to recover the loss on the receiver. Subsequent receivers will be cheaper, and SpaceX plans to produce most of them in-house in the future.

 

[anorlunda]

It will be very interesting to find out how many subscribers Starlink can hope to get globally. 1 billion subscribers at $100/month, would mean a gross income of 1.2 trillion per year. Maybe that is more than they can handle. There are rumors about an IPO, and if that happens, Starlink will have to disclose their business plan.

With Starlink, you will have to share bandwidth with your neighbors. Therefore, performance in the most dense cities will be the lowest, and conversely the highest for rural customers. Rural customers are the ones most starved for Internet right now, so I would guess that Starlink would be especially appealing to them.

It will also be interesting to learn if countries like China try to block Starlink or to regulate it. China has had great success so far with the great firewall.

It will also be interesting if those phased array antennas will be able to keep a lock for mobile installations. I'm thinking of the roof of a truck or a boat rocking in heavy seas.

 

[mfb]

Starlink can't handle a billion users (with high bandwidth for each user), and it's interesting in rural areas only. If they manage to add laser links then they can sign up a few urban customers interested in the lowest possible pings.

They hope to get ~$30 billion/year in revenue in 10+ years. The price for customers will be adjusted based on the local markets, it means a bit over 30 million users.

It will also be interesting to learn if countries like China try to block Starlink or to regulate it.

SpaceX needs to get permissions in each country they want to service. For now they have that in the US and Canada and some partial approvals elsewhere.

Starlink has been tested successfully on aircraft and they have some devices on their ships. They have GPS and can detect their orientation, a bit of movement from a ship shouldn't make a difference.

 

[anorlunda]

Spacex just released this video yesterday answering technical questions about Starlink.

 

[mfb]

Answers as text

 

[mfb]

8 patents related to the receiver

 

[berkeman]

[Note -- an off-topic discussion about YouTube videos has been removed from this thread]

 

[sophiecentaur]

[Note -- an off-topic discussion about YouTube videos has been removed from this thread]

No prob. Less is more!