Space Solar Power Project
(www.spacesolar.caltech.edu)
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If memory serves: microwave power to the ground dissipates as a function of R to 4th power. Even a bigger collector.
It the ground intensity should go as the system brightness (total power) divided by the square of the line-of-sight radius (1/R^2). The spread angle is typically equal parts diffraction spreading and beam pointing jitter.
There is also an interesting relationship between the projection aperture diameter (D1) and the receiver diameter (D2), of (D1)(D2) = 4 L R, where L is the wavelength of the beam and R is the line-of-sight radius (assuming beam jitter = diffraction spreading). It drives you into very large D1 and D2.
Power density on the ground needs to be very low so you don't fry birds, people, airplanes or animals. In space, since it's closer to the source you have satellites (like hundreds of starlink?) to worry about. Also, eclipse issues depending on the orbit, which implies energy storage somewhere so as to have uninterrupted service? Might be a good space weapon, though if you could point it and focus the energy somehow.
And it's got to be at geo-sync or the target moves, duh!
All true...and it imposes limits on the practicality of the approach, typically huge rectenna arrays on the ground to capture the download. I don't know what "eclipse issues" you are thinking of. Not a problem with geostationary orbit. Not a likely problem with any other orbit (lots of space up there), but non-stationary orbits mean only temporary coverage of the delivery site. No feasible energy storage. (It's hard enough to get the power, without deciding not to use it.) Inherently a space weapon due to the necessary beam control functionality, a fact that hardly anyone appreciates.