Analog Communication is a data transmitting technique in a format that utilizes continuous signals to transmit data including voice, image, video, electrons etc. An analog signal is a variable signal continuous in both time and amplitude which is generally carried by use of modulation. Analog circuits do not involve quantization of information unlike the digital circuits and consequently have a primary disadvantage of random variation and signal degradation, particularly resulting in adding noise to the audio or video quality over a distance. Data is represented by physical quantities that are added or removed to alter data. Analog transmission is inexpensive and enables information to be transmitted from point-to-point or from one point to many. This course provides comprehensive practical exposure in the terminology, principles, and applications of the analog communication circuits.

Objective:

In this laboratory students has to  perform the experiments of  Communication Engineering for the first time. Training in this laboratory is done mainly through excellent hardware set up as per the WBUT syllabus. Beyond the syllabus interested student can perform experiment using discrete electronic components. Computer simulation using MATLAB help them to understand the principle of different analog communication techniques very easily.

List of Major Experiments:

i) Measurement of modulation index of an AM signal.

ii) Measurement of output power with varying modulation index f an AM signal(for both DSB-SC & SSB).

iii) Measurement of distortion of the demodulated output with varying modulation index of an AM signal (for both DSB-SC & SSB).

iv) Measurement of power of different frequency components of a frequency modulated signal & the measurement of the bandwidth.

v) Design a PLL using VCO & to measure the lock frequency.

vi) Design a FM demodulator using PLL.

vii) Pre Emphasis – De Emphasis Circuits

viii) Design of Mixer

ix) Diode Detector Characteristics

x) Determination of selectivity, sensitivity and Fidelity of Radio Receiver

Major Equipments:

1. Cathode Ray Oscilloscope-30 MHz (APLAB)
2. Digital Storage Oscilloscope (TEKTRONIX TPS2024)
3. Function Generator (SCIENTIFIC)
4. Amplitude Modulation Trainer (MICROTECH INDUSTRIES)
5. DSBSC, SSBSC Transmitter and Receiver (MICROTECH INDUSTRIES)
6. Spectrum Analyzer (TEKTRONIX RSA306)
7. Analog and Digital Experiment Platform (SCIENTECH ST 2613)
8. VCO Trainer Kit (MICROTECH INDUSTRIES)
9. PLL Trainer Kit (MICROTECH INDUSTRIES)
10. Various Power supplies (DC and AC)
11. Distortion Analyzer (TEKTRONIX AA501A)
12. Digital Multimeter (METRAVI)
13. Frequency Modulation Trainer (MICROTECH INDUSTRIES)
14. Super Heterodyne Radio Receiver Trainer (MICROTECH INDUSTRIES)