Tagged: MAX2120

Lantern: A New 925 MHz to 2175 MHz RTL2832U Based SDR for Satellite Reception

Over on Reddit we’ve seen news about a new 925 MHz to 2175 MHz RTL2832U based software defined radio which is currently under development. It is called the “Lantern” and is being developed for the Outernet project.

The Outernet project aims to be a “library in the sky” satellite based service that will provide free access to daily downloads of data such as books, news, videos and other information. It’s goal is to provide people who may not have easy physical or uncensored access to the internet an easy way to access daily information.

Outernet Overview Poster
Outernet Overview Poster

To achieve this goal the Outernet project needs a good low cost satellite receiver. The RTL-SDR is a good candidate, but it’s performance at about 1.5 GHz isn’t great, and this appears to be the frequency Outernet wants to use. To improve the performance for satellite reception at these frequencies they have redesigned the RTL-SDR by replacing the R820T2 tuner with a MAX2120 tuner chip which tunes from 925 MHz to 2175 MHz. They have also improved the components used and the PCB layout. The regular RTL2832U chip is used as the ADC and USB interface, so the maximum bandwidth and ADC bit depth remain the same.

The Lantern is currently being prototyped and there is a discussion about it on Reddit. They are aiming for a price point below $20, but note that it will take time to get to that low price as mass production will be required.

The current Lantern prototype.
The current Lantern prototype.