# Electronics and Communication Engineering - Satellite Communication - Discussion

Discussion Forum : Satellite Communication - Section 1 (Q.No. 5)
5.
A 20 m antenna gives a certain uplink gain at frequencies of 4/6 GHz. For getting same gain in the 20/30 GHz band, antenna size required is metre.
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Explanation:
No answer description is available. Let's discuss.
Discussion:
12 comments Page 1 of 2.

Vaishu said:   4 years ago
How 5?

THANAM SIVA said:   7 years ago
Thanks for explaining it.
(2)

Amul said:   8 years ago
Thanks for the explanation. It's very easy to understand.

Indu said:   8 years ago
How put 5?
(1)

Suresh said:   9 years ago
Thanks to explaining all of these.

Zarana said:   9 years ago
How put 5?

We need height of 20/30 frequency. So do 4*5/6*5 & dived by 5 to 20 meter height?

(1)

Shivanirajput said:   9 years ago
Antenna diameter is inversely proportional to frequency. So f*5 = d/5 = 4m.

Anurag Nande said:   9 years ago
Antenna diameter (d) is inversely proportional to the operating frequency (f).

So d = k*(1/f).

Note :- Here k is constant.

For up link f = 4GHz for down link f = 6GHz.

d = k*1/4 d = k*1/6.

d/5 = k*1/(4*5).

d/5 = k*1/(6*5).

d/5 = k/20 ---(1)

d/5 = k/30----(2).

So the resultant size of antenna from equation (1) and (2):

Size = d/5 = 20/5 = 4m.

Size = 4m.
(1)

Shreya said:   9 years ago
20m antenna-----4/6GHZ-----multiply by 5.

?---------------20/30GHZ.

4*5/6*5-----20/5=4m.

Nirav Solanki said:   10 years ago
Here frequency is multiplied by 5 means the wavelength is divided by 5.

Now length of antenna is directly proportional to the half of the wavelength. So the ultimate length of antenna is divided by 5.