Starlink Question that needs another thread I think

[EricJ]

13 hours ago, cliffy said:

Anyway you look at it Starlink has a much higher RF output than any cell phone (due to antenna distances needed)

And there's been no frequency interference testing with our microwave radio units  

Also Starlink does not publish the front to back ration of its antennas

I wouldn't be too worried about frequency interference on most modern equipment.   Channel isolation and filtering these days is pretty good, and the requirements and testing to assure out-of-band radiation is minimized are pretty good as well.    There's so much stuff out there these days and you rarely hear of common user equipment interfering with each other on different frequencies.

There won't be a traditional front-to-back ratio spec on Starlink antennas since they are adaptive and electronically steerable.   The beam shape changes radically depending on the relative location of the satellite that it's trying to communicate with, which moves across the sky pretty quickly.   A user in a front seat of a Mooney with a terminal on the glareshield will be mostly exposed to antenna pattern sidelobes, and they'll be constantly changing as the beam is electronically steered and adapts.   The good news is that sidelobes are usually pretty low-power compared to the main lobe, but who knows how good Starlink's beem steering and adaptation and sidelobe control is.   It might be pretty sloppy and have ugly sidelobes, which wouldn't be too surprising for something that has to do a lot of fast beamforming. 

[Yetti]

12 minutes ago, EricJ said:

Cellular systems are all over the spectrum map these days.    They've been sucking up available spectrum in many different bands for quite a while.   I lost track of all of them a long time ago.

 

This antidote is from the late 1980s.   Next up is the story of how microwave ovens got started. 

[M20F]

I wear special undergarments fashioned from rolled aluminum sheeting to protect my vitals.

[Shadrach]

53 minutes ago, M20F said:

I wear special undergarments fashioned from rolled aluminum sheeting to protect my vitals.

That will do nothing to stop their ability to sap and impurify all of your precious bodily fluids...

[cliffy]

Satellite movement (degrees/min) on a constellation that is about 450 miles up must be interesting to engineer for 

considering the antenna (in an airplane) and the satellite are both moving  at the same time.

After reading on how the stationary antennas actually track (active not static) it makes it an even more interesting subject.

Hadn't thought about side lobes

Cut a few Smith charts while airborne way back when.

All my antenna design and experience goes back 50 years ago when I was working for an ECM company 

during the Viet Nam war. All our magic stuff back then is Model T stuff today- not applicable I guess. 

We put every antenna on the F-111 and the jammer antennas on the B-52 when they were getting shot down.

Interesting story on the delivery of the first of those antennas but for another  time. 

[dkkim73]

6 hours ago, M20F said:

I wear special undergarments fashioned from rolled aluminum sheeting to protect my vitals.

Why not? If thin foil works for my head (you all suspected it) why not elsewhere?