Q. What is Elementary Diode Circuits?

Semiconductor diodes are used in a wide variety of applications. Their usage abounds in communication systems (limiters, gates, clippers, mixers), computers (clamps, clippers, logic gates), television (clamps, limiters, phase detectors), radar (power detectors, phase detectors, gain-control circuits, parametric amplifiers), and radio (mixers, automatic gain-control circuits, message detectors). Several simple diode circuits are presented in this section to serve only as examples.

In solving circuit problems with a nonlinear element, such as a diode, a useful technique employed in many cases is a graphical approach. After plotting a nonlinear characteristic of the element, such as the volt-ampere characteristic of a diode, one can superimpose a plot of the circuit response (excluding the nonlinear element), which is the equation of a straight line in the i-v plane given by the loop equation for the network.

Such an equation of the straight line is known as the load line equation. The intersection of the load line with the characteristic of the nonlinear element in the i-v plane determines the quiescent (operating) point, which is the desired solution.