Voiceband Modem and Channel

Innovative Technologies in Education (ITE)

The superheterodyne receiver and synthesizer module will cover the basic principles of the superheterodyne receiver as currently used in modern communications systems. The radio frequency (RF) signal will be converted to an intermediate frequency (IF) signal.
The module will provide auxiliary functions such as a precision RF signal generator, an RF attenuator and an RF distortion generator. The student will be able to test receiver performance such as image frequency rejection, noise figure, selectivity, mixing principle and PLL frequency synthesis that could not be achieved with a standard AM receiver.

RECOMMENDED EXPERIMENTS

1. Mixing principle 2. Image frequency 3. Noise figure & sensitivity 4. Selectivity 5. Automatic gain control 6. PLL-based frequency synthesizer used as a local oscillator

TECHNICAL SPECIFICATIONS

The superheterodyne receiver and synthesizer module should consist of the following main blocks:

- Tuneable Rf Filter - Local Oscillator - Mixer - If Filter - Attenuation Control - Variable Attenuator - Crystal Reference Generator - Phase Detector - Loop Filter - Vco - Programmable Divider - Non-linear Device - Low Frequency Adder