f. Occupied bandwidth.

This term is defined as the frequency

bandwidth that, below its lower and above its upper frequency limits,

the mean powers radiated are equal to 0.5 percent of the total mean

power radiated by a given emission.

In some applications, for

example multichannel radio frequency division multiplex systems, the

percentage of 0.5 may lead to certain difficulties in the practical

application of the definitions of occupied and necessary bandwidth

for these, a different definition may prove useful.

LESSON 1 - EXERCISE 1

Complete items 1 through 4.

1. The units for frequency are hertz and a hertz equals one cycle

per second.

a.

True.

b.

False.

2. What

frequency

range

is

usable

and

is

controlled

by

communications-electronics frequency management?

a.

3 kilohertz to 3000 gigahertz.

b.

3 kilohertz to 300 gigahertz.

c.

3 megahertz to 300 gigahertz.

d.

3 kilohertz to 30 gigahertz.

3. One television channel occupies approximately ten times the

spectrum space required for an entire commercial amplitude modulation

broadcast band.

a.

True.

b.

False.

4. What frequency range does the commercial broadcast band operate

in?

a.

very high frequency

c.

medium frequency

b.

high frequency

d.

Check your answers with the exercise solutions on page 99.