Some of the key design issues that occur in computer networks are present in several layers. Below, we will briefly mention some of the more important ones.Every layer needs a mechanism for identifying senders and receivers. Since a network normally has many computers, some of which have multiple processes, a means is needed for a [...]
A transistor is a linear semiconductor device that controls current with the application of a lower-power electrical signal. Transistors may be roughly grouped into two major divisions: bipolar and field-effect. In the last chapter we studied bipolar transistors, which utilize a small current to control a large current. In this chapter, we’ll introduce the general [...]
The term saturation is applied to any system where levels have reached their maximum values. A saturated sponge is one that cannot hold another drop of liquid. For a transistor operating in the saturation region, the current is a maximum value for the particular design. Change the design and the corresponding saturation level may rise [...]
The transistor is a three-layer semiconductor device consisting of either two n- and one p-type layers of material or two p- and one n-type layers of material. The former is called an n-p-n transistor, while the latter is called a p-n-p transistor. Both are shown in Fig. 3.2 with the proper dc biasing. The dc [...]
A waveguide is a special form of transmission line consisting of a hollow, metal tube. The tube wall provides distributed inductance, while the empty space between the tube walls provide distributed capacitance: Figure 20.1 Fig: Quarter wave 150 transmission line: Figure 20.1: Quarter wave 150 transmission line section matches 75 line to 300 antenna. Figure [...]
In DC and low frequency AC circuits, the characteristic impedance of parallel wires is usually ignored. This includes the use of coaxial cables in instrument circuits, often employed to protect weak voltage signals from being corrupted by induced “noise” caused by stray electric and magnetic fields. This is due to the relatively short time spans [...]
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