LESSON 1
RF AMPLIFIERS
SCOPE.....................................Block diagram of basic FM receiver;
principles of operation of RF amplifiers
to include single and two-stage circuits.
CREDIT HOURS..............................2
TEXT ASSIGNMENT...........................TM 11-668, para 52-61, 69-71;
Attached
Memorandum, para 1-1 thru 1-3
MATERIALS REQUIRED........................None
SUGGESTIONS...............................Read the assignment in TM 11-668 before
you read the attached memorandum.
LESSON OBJECTIVES
When you have completed this lesson, you will be able to:
1.
Determine the level of the noise voltage at the RF amplifier.
2.
Determine the input signal requirements for given RF bandwidths.
3. Determine the current, voltage, and signal changes that occur when the AVC and
AGC voltages are changed.
4. Distinguish
among
the
various
circuit
configurations
that
are
used
as
RF
amplifiers.
5.
Analyze the various types of RF amplifiers.
ATTACHED MEMORANDUM
1-1.
TRANSISTOR CONFIGURATIONS OF RF AMPLIFIERS
There are three principal criteria involved in selecting the transistor
configuration to be used as an RF amplifier: power gain, impedance matching, and
internal feedback. Based on these three items, the common-emitter configuration is
generally chosen.
The common-base configuration is chosen at times, but the
common-collector configuration is seldom selected.
a. Power Gain.
The common-emitter configuration offers the power gain, better
than 10 decibels (db) above the common-base type. The use of the
2
Previous Page
