Co ordinate system It is worth studying this diagram as it represents particular choices among many which are possible and the details of the equations to be developed depend upon these choices. We have followed in this diagram the majority but by no means universal tradition followed by writers...
Con fi guration In the normal arrangement, the stubs are separated by a distance of L = 3λ/8 as shown in Figure 3.12, but other separations are possible, with appropriate variations to the procedure described below. In Figure 3.12 we see that the load admittance YL and a stub known as S2 are bot...
Con fi guration The matching system is shown in Figure 3.9. For the reasons described in a later paragraph we are working in admittance terms. At the right of the diagram is shown is shown a load admittance YL. A line of characteristic admittance Y0 and length l connects the load to a junction p...
Consequences at a boundary As said above we make medium 1 the perfect conductor. This is so that the vector ˆn points out into the adjacent space, as shown in Figure 6.3. For d.c. fields we would have the forms already quoted as equation 6.1 to 6.4 with Et1 and Dn1 set to zero, viz Et2 = 0 (6.13)...
Conservation of Charge Concept As our first major concept we begin with the notation that there is a thing called charge which is conserved. It can be stationary or in motion. It can be used to probe an electromagnetic field; it is discrete but in such small amounts as not to concern us at the m...
Constitutive Parameters Having generalised in Section 4.4 Maxwell's Equations to take into account the effects of polarisation and magnetisation within media, we find we are left with too few equations in the number of unknowns now involved, to obtain a solution. The number of equations in the e...
Current re fl ection factor The current reflection factor Γi is defined by Γi = Ireγz If e−γz . (2.76) This definition is the obvious dual of the previously given definition in equation 2.52 for voltage reflection factor. Substituting for If and Ir in terms of Vf and Vr from equations 2.48 an...
De fi nition of the Smith Chart The Smith Chart provides a graphical method for the visualisation of conditions on a transmission line and for the solution of transmission line problems. The method rests on the fact that the voltage reflection factor Γv defines the conditions on the line, and tha...
Design of stubs Practical reasons, will be discussed in lectures, make it more convenient in many transmission line problems to work in admittance terms. Thus when we design a stub, we are seeking to find the stub length which will provide a part...
Detail of the procedure The details of the procedure are illustrated in Figure 3.13 and the discussion below. As indicated in Figure 3.12, the length 3λ/8 length of line, the two stubs and the main line to be matched all have a characteristic admittance Y0. This is the normal case but the proced...
