An open-source 240-antenna array to bounce signals off the Moon
Posted by Technical-March6780@reddit | hardware | View on Reddit | 13 comments
Posted by Technical-March6780@reddit | hardware | View on Reddit | 13 comments
diskowmoskow@reddit
I don’t have any use for this but looks absolutely fascinating open source project
too_tall87@reddit
Can anyone shed some light on how you achieve ~34 dBi of array gain with 72 elements? Are we expected to believe the element pattern gain is ~17 dBi at boresight?
CallMePyro@reddit
Heh, I have an eng who I work with that behaves exactly like you
Technical-March6780@reddit (OP)
240 elements, and each element has another \~10dBi element gain
too_tall87@reddit
Thanks. I was looking at the Starter Phased Array specs with 72 elements.
unsurejunior@reddit
The unit quad cell looks pretty affordable. If I can remember this exists when it's available, I'd buy one for sure
Jeep-Eep@reddit
How much bandwidth could you get out of solutions like this?
Technical-March6780@reddit (OP)
The update https://moonrf.com/updates/
mentions 80 MSPS on each antenna. I think that's I+Q, so 80 MHz of bandwidth. But it looks like their mixer front-end may be more limited to like 60 MHz max.
Jeep-Eep@reddit
I'm wondering at what scale and sophistication of the array you'd need to use Luna like a giant version of the Echo passive comsats for shit tier internet.
kc2syk@reddit
EME "earth-moon-earth" or "moonbounce" is a thing in amateur radio. People make massive antenna arrays to do this on VHF and UHF frequencies (2m, 70cm and 23cm ham bands). Image search for "VHF EME array" or "UHF EME array" to see what some people have built.
too_tall87@reddit
Another question I was wondering is how they’ll handle ~307 Gbps data rates (240 elements, 80 MSPS, 8+8 bit I & Q) across the full system. The QuadRF specs mention data rates for each element, and there’s other mentions of MIMO and RF imaging, which makes me think they’re expecting fully elemental data.
Technical-March6780@reddit (OP)
looks to be daisy chained... so each RF board digitally adds it's 4-antenna contribution (with appropriate phase shifting) to the upstream SERDES and then the result is downstream in the chain
moschles@reddit
I like everything about this.