Frequency Shift Keying (fsk)

Question 1

What is frequency shift keying ?

Answer 1

A modulation whereby the RF carrier is caused to alternate between two or more discrete frequency values

Question 2

What is shift?

Answer 2

The difference between two adjacent frequency levels on a two level FSK.

Question 3

What is excursion?

Answer 3

The difference from the highest frequency level to the lowest frequency level.

Question 4

What is deviation frequency ?

Answer 4

The difference in frequency from

The centre of the FSK to the highest or lowest frequency level.

Question 5

What is square wave modulation index SMI ?

Answer 5

The ratio of the deviation frequency (fd) to the modulating frequency (fm)

Question 6

How do we work out SMI?

Answer 6

Bauds

Question 7

Minimum bandwidth is equal to what ?

Answer 7

2(fd+fm)

Or

Shift + bauds

Question 8

If the modulation index is high what are we likely to see on the spectrum ?

Answer 8

The frequency levels are very distinct and easy to see each frequency carrier.