Microwave reflection efficiency and atmospheric absorption

[cosmo123]

I have tried searching for answers to these questions but i can't seem to find them, so if anyone could help me it would be greatly appreciated.

How efficiently you can reflect microwaves? I know visible light can be reflected at 99.99% efficiency or something ridiculous like that, is it the same for microwaves?
Also, how much are microwaves absorbed as they pass through the atmosphere? I haven't been able to find any exact figures.
Finally, does anyone know what is the most powerful continuous-wave maser that's been made?

 

[f95toli]

They can be reflected extremely efficiently; I don't think there is any practical difference between microwaves and light in this respect.

The absorption will depend on the frequency of the microwaves (remember that "microwaves" refer to frequencies from a few hundred MHz up to about 1 THz or so) but also on the atmosphere; the amount of waver vapour (i.e the humidity) can make a huge difference, especially when dealing with higher frequencies.

 

[cosmo123]

They can be reflected extremely efficiently; I don't think there is any practical difference between microwaves and light in this respect.

The absorption will depend on the frequency of the microwaves (remember that "microwaves" refer to frequencies from a few hundred MHz up to about 1 THz or so) but also on the atmosphere; the amount of waver vapour (i.e the humidity) can make a huge difference, especially when dealing with higher frequencies.

Ive been trying to find some figures for it at certain humidities or certain wavelengths, but i can't really find anything. I know the "radio window" goes from about 1cm to 11m wavelengths, where microwaves are absorbed very little, but it would be very useful to have some figures to work with.