This set of RF & Microwave Circuit Design Multiple Choice Questions & Answers (MCQs) focuses on “Antenna Radiation”.

1. Antennas that radiate energy only in a specified are called anisotropic antennas.
a) True
b) False

2. The expression for pointing vector of an isotropic point source at a distance ‘r’ from the source is given by:
a) P/ 4πR2
b) P/4π
c) P/ 4πR
d) P×4πR2

3. An antenna source that radiates energy uniformly in all the directions is called:
a) Isotropic source
b) Anisotropic source
c) Point source
d) None of the mentioned

4. A source has a cosine radiation-intensity pattern given by U=UM cos (θ). The directivity of this source is:
a) 2
b) 4
c) 6
d) 8

5. A source has a radiation intensity pattern given by U=UM sin θ. The directivity of the source with this power pattern is:
a) 1
b) 1.27
c) 2.4
d) 3.4

6. A source with a unidirectional cosine squared radiation intensity pattern is given by UMcos2 (θ). The directivity of the given source is:
a) 6
b) 8
c) 2
d) 7

7. A source has a cosine power pattern that is bidirectional. Given that the directivity of a unidirectional source with cosine power pattern has a directivity of 4, then the directivity of the unidirectional source is:
a) 1
b) 2
c) 4
d) 8

8. A source has a sine squared radiation intensity power pattern. The directivity of the given source is:
a) 1.5
b) 3
c) 2.5
d) 3.5

9. Considering distance as a parameter, two types of field zones can be defined around an antenna.
a) True
b) False

10. If the field strength at receiving antenna is 1 µV/m, and the effective aperture area is 0.4 m2 and the intrinsic impedance of the medium is 377 Ω, then the power received by the antenna is:
a) 1.06 pW
b) 1.06 fW
c) 2 µW
d) None of the mentioned