ET ATT WEEK 13 Questions and Answers 100% Correct | New Update 2025

ET ATT WEEK 13 Questions and Answers 100%
Correct | New Update 2025
AM(Amplitude Modulation) Characteristics - ANSWER Amplitude changes(intel
is in amplitude), frequency stays the same
Contains:
a. Original Carrier Frequency
b. Modulation Signal
c. Sum of the carrier and modulation signal
d. Difference of the carrier and modulating signals


AM Receiver is made of: - ANSWER 1.) RF Section
2.) Mixer
3.) LO
4.) IF Amplifier
5.) AM Detector
6.) AGC(Automatic Gain Control)
7.) AF Amplifier


AGC(Automatic Gain Control) - ANSWER Automatically controls amplitude
increase from original input to amplified output.
Eliminates fluctuations in the output when the RF input varies.


Modulation Percentage Formula - ANSWER % Mod = (Vmax - Vmin)/(Vmax +
Vmin) x 100

, Heterodyning - ANSWER Changes a signal's frequency, WITHOUT changing the
signal's intelligence.


Heterodyned Signals - ANSWER Contain:
1.) Original RF Signal
2.) Orginal LO Signal
3.) Sum of the RF and LO signals
4.) Difference of the RF and LO signals


Mixer - ANSWER Mixes the carrier signal and LO signal to produce IF.


IF(Intermediate Frequency) - ANSWER Always 455 kHz in AM receivers.
Always 10.7 MHz in FM receivers.


Synthesized Tuning - ANSWER Uses a lower reference frequency (usually from
a PLL) to create a wide range of high frequencies.


PLL(Phase Locked Loop) - ANSWER A circuit that constantly adjusts to match an
input frequency.
Helps filter noise.


A PLL is made of: - ANSWER 1.) Phase Detector
2.) Frequency counter/divider
3.) VCO
4.) Loop Filter