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Variation of Tv(z)with position

Taking into account thc variation of forward and backward wavcs with position wc havc T v(z) =

Vi€yz

VfC-yz= rv(0)C2yz(2.53)

When z = L, i.e. at the load, we denote T vby T v(L), the reflection factor of the load. When z = S, i.e. at the source, wc denote T vby T v(S), thc reflection factor looking into

the linę at the source end. From cquation 2.53, then T v(S)

Tv(L)

C2yS

C2 y L = C-2 y (L-S) = e-2 y I (2.54)

It may be worth cmphasising that in equation 2.53 thc cxponcnt on the right hand sidc is positive, whcreas in cquation 2.54 the exponent on thc right hand sidc is negative.

Both of these signs correctly express the fact that the voltage reflection factor becomes retarded in phase as we move back from the load.

It will hopefully be explained in lectures that this behaviour is as expected, and can be used as an aid to memory of the sign of the exponents in equation 2.53 or equation 2.54.