Antennas Practice Test 4

1. Find the optimum aperture angle for H-plane horn with aperture 12λ and path travel difference 0.4λ?

75.9°

1.59°

7.59°

15.18°

2. In Horn antennas impedance matching is provided by _______

Balun

flaring

increasing Power

decreasing axial length

3. What is the corner angle of a flat reflector antenna?

60°

90°

180°

45°

4. If flaring is done in the magnetic field direction of the rectangular waveguide then it is called ______

Pyramidal horn

E-plane horn

Conical horn

H-plane horn

5. The power gain of the parabolic reflector with circular aperture of diameter 10λ?

600π

10π

100π

360π

6. Which of the following is a dual reflector antenna?

Cassegrain antenna

Offset reflector antenna

Wire antenna

Parabolic antenna

7. Which of the following combination forms a Cassegrain antenna?

The main reflector is hyperbolic and sub-reflector is convex

The main reflector is parabolic and sub-reflector is hyperbolic

The main reflector is hyperbolic and sub-reflector is parabolic

The main reflector is parabolic and sub-reflector is concave

8. Which of the following is the correct form of design equations of a horn antenna?

Length \(ρ=\frac{h^2}{4δ}, flare\, angle=2tan^{-1}⁡\frac{h}{2ρ}\)

Length \(ρ=\frac{h^2}{4δ}, flare\, angle=tan^{-1}⁡\frac{h}{2ρ}\)

Length \(ρ=\frac{h^2}{8δ}, flare\, angle=2tan^{-1}⁡\frac{h}{2ρ}\)

Length \(ρ=\frac{h^2}{8δ}, flare\, angle=tan^{-1}⁡\frac{h}{2ρ}\)

9. Which of the following statements is false for a corner reflector antenna?

System efficiency depends on spacing between reflector vertex and the feed

Increases directivity in the forward direction

Back radiation is not reduced compare to the plane reflector

Angle between the reflecting plates is called included angle

10. Which of the following reflector antenna is formed by joining two plane reflectors at some angle (≠nπ)?

Cheese

Parabolic

Corner

Truncated