how to calculate antenna gain

Hi,

I have a doubt.

Pr=power received from the patch antenna
Pt=power transmitted from the patch antenna
R=distance
lambda=wave length
Gt=gain of transmitting antenna (the patch antenna)
Gr=gain of receiving antenna (the term include the losses of the receiving system)
Pgr=3.14

So,

Gt= (4PgrR/lambda)2 Pr/(Pt*Gr)

Gt (dBi)= 10 log Gt


I have the values:

Pr= -5dBm
Pt=20dBm
Gr=? ( don't know)
R=distance which is 1.8meter

What I will get in Gt? What is actually Gr? I know it stands for gain of receiver but don't know how to figure the value. Can anyone tell me?

Can anyone help me to calculate the gain in dBi which is Gt.


Waiting for your reply.

thank you.

Regards,
Saran

see this page .......
https://www.edaboard.com/ftopic334689.html

Hi Ravi,

The page that you showed me are written by me as well.

Now, I'm just explained the current situation and I need you guys to help to find out the Gt(dBi).


Can u help me?

I'm would be very grateful to you. Waiting for your reply.

Thank you.

Regards,
Saran