L Section in Four Terminal Network:

L Section in Four Terminal Network is very much similar to half section consisting series and shunt arm impedances Z₁ and Z₂ respectively as shown in the Fig. 8.28. The ladder network can be analyzed into a series of L sections rather than T and π sections. The main application of L section is in matching of impedances between two sections.

Interative Impedance (Z′₀):

Consider Fig. 8.29 (a),

Finding roots, we can write,

Consider Fig. 8.29 (b),

Finding roots, we can write,

Image Impedances (Z_i):

Consider Fig. 8.29 (a)

Thus, image impedance Z_i1 at port 1 is given by

Similarly,

Thus, image impedance Z_i2 at port 2 is given by