Prelim 2 Flashcards
Frequencies that are high enough to be efficiently radiated by
the antenna and propagated through free space.
Radio Frequencies
The modulated output waveform from an AM modulator is?
AM Envelope
Sometimes called conventional AM or simply AM.
AM DSBFC
The band of frequencies between fc – fm (max) and fc.
Lower Sideband
Any frequency within the lower sideband is called.
Lower Side Frequency
The band of frequencies between fc and fc + fm(max)
Upper Sideband
The term used to describe the amount of amplitude change
(modulation) present in an AM waveform signal.
Coefficient of Modulation
The coefficient of modulation stated as a percentage.
Percent Modulation
Any frequency within the upper sideband is called?
Upper Side Frequency
The maximum percent modulation that can be imposed without
causing excessive distortion.
100%
Maximum Coeff of Modulation
1
The _______ in a transmitter where modulation occurs
determines whether the circuit is a low or a high-level transmitter.
Location
The modulation takes place prior to the output element of the
final stage of the transmitter.
Low-Level Modulation
The modulation takes place in the final element of the final
stage where the carrier signal is at its maximum amplitude
High-Level Modulation
A form of AM where signals from two separate information
sources modulate the same carrier frequency at the same time without
interfering with each other. The information sources modulate the same
carrier after it has been separated into two carrier signals that are 90º out
of phase with each other.
Quadrature Amplitude
Modulation
( QAM )
