Antennas Practice Test 5

1. Which of the following is used to avoid the aperture blockage due to secondary reflector?

Plane reflector

Parabolic antenna

Cassegrain

Offset feed system

2. Which of the following regarding the Cassegrain feed system is false?

It is a dual reflector antenna

Spill over is reduced

A convex sub-reflector is used

Minor lobe radiation increases

3. Which of the following antenna is obtained by removing a small area of metal from an infinite ground plane?

Yagi-Uda

Dipole

Slot antenna

Plane reflector

4. Which of the following statement is true regarding a Gregorian antenna?

Sub-reflector is an ellipsoidal with its concave facing feed

Sub-reflector is an ellipsoidal with its concave facing reflector

Sub-reflector is a hyperboloid with its convex facing feed

Sub-reflector ellipsoidal lies closer to the focus of the paraboloid

5. Cassegrain antennas cannot be used in radio telescopes.

False

True

6. Which of the following allows independent optimization of feed mechanism?

Aperture coupling

Coaxial feed

Microstrip line feed

Proximity Coupling

7. In which of the following type of antenna a patch is created during fabrication?

Wire antenna

Lens antenna

Horn antenna

Microstrip antenna

8. Which of the following cannot be used to reduce the radiation resistance in slot antenna for a given slot size?

Stub tuning

Center feed

Inclined slot

Off-center feed

9. What is the impedance of 2- element slot antenna with single slot antenna resistance =500Ω?

125Ω

250Ω

1000Ω

500Ω

10. Which of the following is true regarding the coaxial coupling feed in Microstrip antenna?

Outer conductor is connected to patch and inner conductor to ground plane

It is connected to patch just like a conducting strip

Inner conductor is connected to patch and outer conductor to ground plane

It contains two different substrates separated by a ground plane