Friis transmission equation

The Friis Transmission Equation is a way of calculating the strength of a signal as it passes through different materials. Think of it like a flashlight that starts off strong and gets weaker as it passes through walls – this equation helps decide how much weaker it will be. The equation is named after its creator, Danish engineer Harald Friis. It looks like this:

Power Received (PR) = Power Sent (PS) x Gain of Receiver (GR) x Gain of Transmitter (GT) / (4π x Distance (d)2 )

Here's what all that means:

PR: This is the power of the signal once it has passed through whatever material or distance it had to go through.

PS: This is the power of the signal as it is sent out in the beginning.

GR: This is a number that tells us how effective the receiver (the thing that is getting the signal) is at picking up the signal.

GT: This is a number that tells us how powerful the transmitter (the thing that is sending out the signal) is.

d: This is the distance between the transmitter and the receiver.

So, the Friis Transmission Equation tells us how much weaker a signal will be when it travels between the transmitter and the receiver.