Please clear my doubt on cable loss of an antenna

Hi All,

I am testing 2 parabolic dish (feedhorn antenna) . Both dish are used as transmit and receive respectively.

Each dish is fixed with cable to the equipment. At the receiver, when I see the reading of -7.8dBm . This testing is done for 5GHz frequency. Distance btw 2 dish is 2.8m. Since I want to find the gain in dBi, I used link budget or friis equation, i got roughly at 25dBi. Cable loss alone is -3.5dBm at 5GHz and at 6GHz is -2.7dBm.

If the cable loss at 5GHz is -3.5dBm, when I testing 2 dish , I got reading at receiver is -7.8dBm at 5GHz.

If I got the cable loss at -1.7 dBm, do I will get same reading at receiver (-7.8dBm) at 5GHz.


Waiting for your reply.

regards,
Saran

Are you sure that at 6GHz the loss is better than 5GHz?

Added after 1 minutes:

I mean how did you tested it? is cable is ok?
because I guess something might be wrong.

The cable is RG316. The connector of the cable at one end is SMA(male) and the other end is N-type (female).

I have 2 cable so i used for both dish to test.

Can you tell, what is diameter of your dish ? I think, that distance btw dish 2.8 m is very low, and I think, that you measure near field.....

Added after 7 minutes:

and please, can you write table, where will be Pr, Pt, Gt, Gr, cable looss, and so on... and what is known and unknown for 5 and 6 GHz ? It will be better for my orientation. Thank