ELECTRONIC DEVICES

Abstract

The electronic systems and equipment such as radio transmitters, radio receivers, electronic exchangers, digital computers, ... etc., are generally composed of electronic circuits. Each circuit performs a predetermined function in the electronic system. Besides the conventional passive circuit elements, an electronic circuit contains electron devices. The main duty of electron devices is amplification and switching. Moreover, they can act as controlled resistors and capacitors. Their inherent nonlinear electrical characteristics are extremely useful in signal processing. A study of the electrical behavior of the electron devices is required not only to design them to meet specific terminal electrical characteristics, but also to apply them efficiently in electronic circuits. Electronic devices can be classified in electron tubes and solid-state devices. In spite of the revolutionary advance in solid state devices since the invention of the transistor by W. Shockley in 1948, electron tubes are still dominant in applications where large power at high frequencies is necessary. This is because of the different nature of current conduction in vacuum tubes and in the solid materials.