1. The Parabolic Antenna

2. Out Line:~ Properties of the Parabolic Antenna
Example of Parabolic Antenna
Parts of the Parabolic Antenna
Radiation patterns, Radiation efficiency, D & G
Radar

4. Properties of Parabolic Antenna
It’s an aperture antenna.
It’s working in the fact that EM waves are reflected by a conducting sheet.
Used in communications ,radar , astronomy.
The dish antenna can transmit and receive in the same time.
It ability to amplify signals is primarily governed by the accuracy of it’s parabolic curve.

5. Properties of Parabolic Antenna
The parabolic carve has the property of reflecting all incident rays arriving along the reflector’s axis.

6. Properties of Parabolic Antenna
This antenna is used for detection and location of objects.
Parabolic dish antenna are used in communication, radar, and astronomy.

9. Parts of the Parabolic Antenna
It Consist of:~
1)Reflector;the reflector must be constructed out of metal in order to reflect the incoming microwave signal.
2)Feed antenna; which it maybe dipole or horn feed-it’s better to use the horn feed.

10. Parts of the Parabolic Antenna
The prime focus antenna: It’s dishes with a focal point directly at the center and the front of the reflector. This antenna is easy to construct and point toward the desired satellite. In the focal point we put a feed horn and it must look back at the dish at such an angle that it can intercept noise.

11. Parts of the Parabolic Antenna
The design of the parabolic antenna
It’s to decide where the focal point (horn feed) must be.

12. The parabolic surface
A parabolic surface has a useful property of being able to convert a diverging spherical wave front into parallel plane wave front, producing a highly focused and narrow beam.

13. The parabolic antenna has the same as the horn antenna for the directivity and for the radiation efficiency; which is:
Directivity=(pi D/λ)^2
=4pi A/ λ^2:θ=0
The radiation efficiency≤1

17. RADAR
r=( λ2Gt2σPrad /(4pi)3Pr )1/4