General formula For every impedance Z we have a corresponding admittance Y = 1/Z. It is easy to show, and should be taken as an exercise, that in admittance terms the formula 2.65 for input conditions becomes YI Y0 = YL cos βl + jY0 sin βl Y0 cos βl + jYL sin βl (2.71) This turns out to ha...
Higher Level Theories The effects of these departures from the assumptions of lumped circit theory become significant when the dimensions of the apparatus we are using become comparable with the electromagnetic wave length at the frequency of operation. In this situation we need a more advanced ...
Imperfect Conductors We regard an imperfect conductor as a medium with a finite (including zero) conductivity. Insulators will under this definition be a sub-class of imperfect conductors. When both media are imperfect conductors, we consider in the next two sections the possibilities of having ...
Interpretation of the solution We consider in turn each of the terms of the solution 2.44 above, and plot the real voltage for t = 0, and for some small time δt later. The results appear in Figures 2.20 and 2.21 respectively. ...
INTRODUCTION TO ELECTROMAGNETIC WAVES Our objective in this section is to derive the properties of simple plane electromagnetic waves in a linear medium free of charges and currents, of which empty space provides an example. We will find that such waves have properties that are easily and fruitfu...
Line matched at the source end There are no reflections at the source. Hence, only the original forward wave and its single reflection are present. The total load voltage is as shown in Figure 2.12. We note that Γv(L) can be positive or negative. Cases of open circuit and short circuit terminati...
Matching If a line is terminated in its characteristic impedance (which is complex for an arbitrary lossy line), i.e. if ZL = Z0, then equation 2.60 shows that ZI = Z0 for any l i.e. the input impedance becomes independent of line length. This is an important practical property, and the line is...
Meaning of matching To give meaning to the word matching, we recall from lumped circuit theory the maximum power transfer theorem for a.c. circuits which indicates that a sinusoidal steady state source of fixed internal voltage VS and source impedance ZS will deliver maximum power to a load impe...
More complicated structures Useful tables of results of transmission line parameters for various further transmission line structures are found in Reference 1. In one edition of that book, Table 8.09 opposite page 444 and Table 1.25 opposite page 26 are of interest. ...
Objective Practical electromagnetic theory problems almost always involve material media and/or finite boundaries. To solve such problems we need firstly a knowledge of how material media react to the internal electromagnetic fields within them, and a knowledge of electromagnetic boundary condit...
