Description

AM MODULATION AND DEMODULATION

Experiment Content :

Introduction to AM Modulation
Generation of Carrier and Modulating Signals
Amplitude Modulation Basics: Observing the AM Waveform
Modulation Index Calculation
Effect of Modulation Index on AM Signal
Double-Sideband (DSB) AM Modulation
Single-Sideband (SSB) AM Modulation
AM Signal Demodulation Techniques
Envelope Detection of AM Signals
Bandwidth Analysis of AM Signals
Power Calculation of AM Signals
Effects of Over-Modulation and Under-Modulation
Frequency Spectrum Analysis of AM Signals
Noise Effects on AM Transmission
Carrier Suppression Techniques in AM
Real-Time Voice Modulation with AM
Comparing AM with Frequency Modulation (FM)
Low-Pass Filtering in AM Demodulation
Super heterodyne AM Receiver Basics
Practical Applications of AM in Broadcasting

Technical Specification :

1. Signal Generation Module
Function Generator
Waveform Types: Sine, square, and triangular waveforms for
carrier and modulating signals.
Frequency Range: 1 Hz to 1 MHz, adjustable.
Amplitude Control: 0–5V peak-to-peak output.
Carrier Signal Generator
Oscillator Circuit: Can use a 555 Timer IC or a dedicated RF
oscillator circuit.
Frequency Stability: Stable output with minimal drift.
2. Modulating Signal Input
Audio Input Module
Microphone or Audio Jack: For inputting audio signals for
modulation.
Amplifier Circuit: Op-amps (e.g., LM358) for amplifying the
modulating signal to desired levels.
Potentiometers
Used for adjusting the amplitude of the modulating signal.
3. Modulation Circuit
AM Modulator Circuit
Mixer Circuit: Combining the carrier and modulating signals
using a balanced modulator or an analog multiplier (e.g.,
AD834).

Output Filter: Low-pass filter to clean the modulated signal.
Modulation Index Control: Adjusting circuitry to vary modulation depth.

4. Demodulation Circuit
AM Demodulator
Envelope Detector: A simple diode and capacitor-based
circuit for demodulating AM signals.
Active Demodulator Circuit: Using op-amps for better performance.
Output Amplifier: To amplify the demodulated audio signal
for output.
5. Output Visualization
Oscilloscope Output
BNC Connectors: For connecting to external oscilloscopes to
visualize the modulated and demodulated waveforms.
Audio Output
Speakers or Headphones: For listening to the demodulated
audio signal.
LED Indicators
Indicators for modulation status, power, and signal presence.
6. Power Supply
DC Power Supply Module
Input: 220V AC mains power.
Output: Regulated 5V and 12V DC outputs for powering
various circuits.
Voltage Regulators
LM7805 and LM7812 to provide stable voltages.
Overload Protection: Fuse protection to prevent circuit
damage.
7. Control and Interface
Control Panel
Knobs and Switches: For adjusting frequency, amplitude, and
modulation depth.
LCD Display Module
Displays information such as modulation index, input/output
levels, and frequencies.
8. Supporting Components
Breadboard or PCB Layout
For easy assembly and prototyping of the circuits.
Connectors and Jumpers
High-quality connectors for reliable circuit connections.
Passive Components
Resistors, capacitors, and inductors used in various circuits
for filtering, amplification, and stabilization.

Accessories :
Single-phase power cord
4mm Banana Socket-1Set
User Manual

Others :

ountry of Origin: China
Manufacturing: Assemble in Bangladesh
Installation
Warranty: 01 year