I used the equation and computed the received power with the following parameters:

• Tranmit antenna diameter 0.3 m,
• Receive antenna diameter 0.3 m,
• Wave length 1310 nm,
• Transmit power 1W,
• Distance 4000 km (LEO-LEO)

My results:

• Gewinn: Transmit side = 117,1355921, receiver side = 117,1355921
• Path loss: 271,6755667
• Receive power: -37,4043824 dBW or 0,000181787 W (181μW)

1W transmit power and 181μW receives power, I think the equation from the original post is wrong. Can PrxPrx be so small?!

 

Hello there. welcome to a AAC!

Can PrxPrx be so small?!

Physics!You think that's impressive 100 years ago a regenerative receiver will open up with a signal I've only 0.60 femto- watts. That's "0.60 quadrillionths of a watt.