MICROWAVE COMMUNICATION QUIZ

Theoretically electromagnetic radiation field strength varies in inverse proportion to the square of the distance, but when atmospheric attenuation effects and the absorption of the terrain are taken into account the attenuation can be as high as the inverse ___________ power of the distance.

Fourth

Third

Sixth

Fifth

TRUE ANSWER : ?
YOUR ANSWER : ?

__________ is the progressive decrease of signal strength with increasing distance.

Modulation

Attenuation

Radiation

Propagation

TRUE ANSWER : ?
YOUR ANSWER : ?

Calculate the effective earth’s radius if the surface refractivity is 301.

8493 mmi

6370 km

6370 mi

8493 km

TRUE ANSWER : ?
YOUR ANSWER : ?

A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be

A decrease in gain

A decrease in range

A reduction in horizontal resolution

No noticeable effect

TRUE ANSWER : ?
YOUR ANSWER : ?

In a pulsed radar set, the STC circuit is used to

Vary the pulse frequency in order to control the maximum target

Increases receiver sensitivity for echoes from targets

Improve the target bearing resolution

Reduce interference from the effects of sea return

TRUE ANSWER : ?
YOUR ANSWER : ?

Rainfall is an important factor for fading of radio waves at frequencies above

1 GHz

10 GHz

100 MHz

100 GHz

TRUE ANSWER : ?
YOUR ANSWER : ?

The Gunn diode oscillator

Generates frequencies which are below 100 MHz

Operates over a positive resistance characteristic

Depends on the formation of charge domain

Is capable of generating continuous microwave power of the order of kilowatt

TRUE ANSWER : ?
YOUR ANSWER : ?

As the electron beam moves through a klystron’s intercavity drift space

Frequency modulation at the input cavity creates velocity modulation at the output cavity

Density modulation at the input cavity creates velocity modulation at the output cavity

Phase modulation at the input cavity creates velocity modulation at the output cavity.

Velocity modulation at the input cavity creates density modulation at the output cavity

TRUE ANSWER : ?
YOUR ANSWER : ?

The main frequency determining element of a klystron is

Its mode of operation

The repeller voltage

The accelerating voltage

Its resonant cavity

TRUE ANSWER : ?
YOUR ANSWER : ?

In a pulsed radar set, the function of the duplexer is to

All of these

Allow the transmitter and the receiver to operate from a common antenna

Aid in calibrating the display unit

Prevent frequency drift in the klystron

TRUE ANSWER : ?
YOUR ANSWER : ?