Calculating the total power received by an antenna

In summary, a radar antenna transmits 50kW at 10 GHz in a narrow beam of 1m^2 area, with plane waves within the beam. When reflected from an aircraft, only 1% of the power propagates towards the antenna. Using the given values for permittivity, permeability, and conductivity, the total power received by the antenna can be calculated as 0.266 W. Further attempts at the problem have also been attached.
  • #1
enginej
4
0
Thread moved from the technical forums, so no Homework Template is shown
A radar antenna transmits 50kW at 10 GHz. Assume transmission is in a narrow beam, 1m^2 in area, and that within the beam, waves are plane waves. The wave is reflected from an aircraft but only 1% of the power propagates i the direction of the antenna. If the airplane is at a distance of 100km,

Calculate: The total power received by the antenna. Assume Permittivity and permeability of free space and conductivity of 10^-7 S/m.

ANSWER: The answer is 0.266 W (I can't seem to get it.)
 

Attachments

  • Application Radar; detection ansd ranging of aircraft.pdf
    260.1 KB · Views: 249
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  • #2
Can you show what you have attempted, so far? Then we will make suggestions to guide you.
 
  • #3
scottdave said:
Can you show what you have attempted, so far? Then we will make suggestions to guide you.

Thanks for the interest, I already attached the PDF file of my work, let me know if you can't see it.
I also attached a second attempt of the problem, to this post.
 

Attachments

  • second attempt.pdf
    213.2 KB · Views: 350
  • #4
I missed that there is a file attached. I will take a look.
 

1. How do I calculate the total power received by an antenna?

To calculate the total power received by an antenna, you will need to know the antenna gain, the signal wavelength, and the power of the signal source. You can then use the formula P = Pg * (λ/4πr)^2, where P is the total received power, Pg is the antenna gain, λ is the signal wavelength, and r is the distance between the antenna and the signal source.

2. What is antenna gain and how does it affect the total received power?

Antenna gain is a measure of the ability of an antenna to direct or concentrate the power received from a signal source in a particular direction. A higher antenna gain means that the antenna can receive more power from the same signal source, resulting in a higher total received power.

3. Can the total received power be affected by the distance between the antenna and the signal source?

Yes, the total received power is inversely proportional to the square of the distance between the antenna and the signal source. This means that as the distance increases, the total received power decreases. It is important to consider the distance when calculating the total received power for an antenna.

4. How does the signal wavelength impact the total received power?

The signal wavelength also plays a role in the total received power calculation. The higher the signal wavelength, the lower the total received power, and vice versa. This is because the power density of the signal decreases as the wavelength increases.

5. Can the total power received by an antenna be greater than the power of the signal source?

No, the total power received by an antenna cannot be greater than the power of the signal source. The antenna can only receive and amplify the power of the signal source, it cannot create more power. However, the total received power can be equal to the power of the signal source if the antenna is perfectly aligned and has a high gain.

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