Communication Engineering Basics

Amplitude Modulation Fundamentals

In the modulation process, the baseband voice, video, or digital signal modifies another, higher-frequency signal called the carrier, which is usually a sine wave. A sine wave carrier can be modified by the intelligence signal through amplitude modulation, frequency modulation, or phase modulation. The focus of this chapter is amplitude modulation (AM). Amplitude Modulation (AM) …

Amplitude Modulation Fundamentals Read More »

frequency Filters

A Filters are a frequency-selective circuit. Filters are designed to pass some frequencies and reject others.

Tuned Circuits

Virtually all communication equipment contains tuned circuits, circuits made up of inductors and capacitors that resonate at specific frequencies.


The gain or loss of a circuit is usually expressed in decibels (dB), a unit of measurement that was originally created as a way of expressing the hearing response of the human ear to various sound levels. A decibel is one-tenth of a bel. When gain and attenuation are both converted to decibels, the overall …

Decibels Read More »


Attenuation refers to a loss introduced by a circuit or component. Many electronic circuits, sometimes called stages, reduce the amplitude of a signal rather than increase it. If the output signal is lower in amplitude than the input, the circuit has loss, or attenuation. Like gain, attenuation is simply the ratio of the output to …

Attenuation Read More »


Gain means amplification. If a signal is applied to a circuit such as the amplifier shown above and the output of the circuit has a greater amplitude than the input signal, the circuit has gain. Gain is simply the ratio of the output to the input. For input (Vin) and output (Vout) voltages, voltage gain …

Gain Read More »

Communication Engineering Basics

Introduction to Electronic Communication Electronic Fundamentals for Communications Gain Attenuation Decibels Tuned Circuits frequency Filters Amplitude Modulation Fundamentals Amplitude Modulation (AM) Concepts Modulation Index and Percentage of Modulation Sidebands and the Frequency Domain AM Power Single-Sideband Modulation classification of radio emissions Amplitude Modulator and Demodulator Circuits basic principles of amplitude modulation Amplitude Modulators Amplitude Demodulators …

Communication Engineering Basics Read More »