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Chapter 1Basic Electronic Concepts and SignalsElectronics may be defined as the science and technology of electronic devices and systems.Electronic devices are primarily non−linear devices such as diodes and transistors and ingeneral integrated circuits (ICs) in which small signals (voltages and currents) are applied tothem. Of course, electronic systems may include resistors, capacitors and inductors as well.Because resistors, capacitors and inductors existed long ago before the advent of semiconductordiodes and transistors, these devices are thought of as electrical devices and the systems that consistof these devices are generally said to be electrical rather than electronic systems. As we know,with today’s technology, ICs are becoming smaller and smaller and thus the modern IC technologyis referred to as microelectronics.1.1 Signals and Signal ClassificationsA signal is any waveform that serves as a means of communication. It represents a fluctuating electricquantity, such as voltage, current, electric or magnetic field strength, sound, image, or anymessage transmitted or received in telegraphy, telephony, radio, television, or radar. Figure 1.1shows a typical signal ft () that varies with time where ft () can be any physical quantity such asvoltage, current, temperature, pressure, and so on.ft ()tFigure 1.1. Typical waveform of a signalWe will now define the average value of a waveform.Consider the waveform shown in Figure 1.2. The average value of ft () in the interval a ≤ t≤b isbft () tb Area ∫daft () ave = ---------------- = -----------------------(1.1)a Period b – aElectronic Devices and Amplifier Circuits with MATLAB Computing, Second EditionCopyright © Orchard Publications1−1