Chapter 3, Transmitters and Receivers Flashcards
A receiver in which selected signals of any
frequency are converted to a single frequency
is called a
Superhet receiver
Delayed AGC
Maintains receiver sensitivity for very
small signals
A receiver with a high IF will successfully
reject
The image frequency
An IF amplifier consists of several stages. These are normally coupled using
Transformer coupling
SSB filters have a typical bandwidth of
3 kHz to 6 kHz
The output signal of a diode detector
comprises the modulated waveform, a small
ripple and a DC component. The DC
component is
Proportional to the carrier strength
What is the principal function of the RF stage
in a superhet receiver?
To reduce second channel interference
In an FM transmitter, the modulating signal is
applied to
The RF oscillator stage
The response of two coupled tuned circuits
appears to be ‘double-humped’. This is a
result of
Overcoupling
A disadvantage of low-level amplitude
modulation is the need for
A linear RF power amplifier
The function of an antenna coupling unit in a
transmitter is
To provide a good match between the RF
power amplifier and the antenna
In order to improve the stability of a local
oscillator stage
A separate buffer stage should be used
A dual conversion superhet receiver uses
A high first IF and a low second IF
The majority of the gain in a superhet receiver
is provided by
The IF amplifier stage
Image channel rejection in a superhet receiver
is improved by
Using a high IF
