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Midseries and Midshunt Terminations

Often several networks are connected one after the other in a "chain," in "cascade," or in "tandem." In such a transmission system, as far as the signal is concerned, the individual networks tend to lose their identity. It is advisable in network study first to investigate the system as a whole.

Figure 4 shows an unbalanced network extending to infinity in both directions. It is desired to select a finite portion of this network to use as a transmission system. Suppose the portion A-B is selected by cutting the network at 1/2Z1. This will give the network of Fig. 5a, and the network is said to have mid-series terminations, because it "starts" and "ends" in 1/2Z1.

Another possibility is to select the finite section C-D (Fig. 5b). This network is said to have mid-shunt terminations. The value 2Z2 is specified because two such impedances in parallel give the impedance Z2 of Fig. 4. The infinite network could have been cut into at any point; then fractional termination would have resulted.

Last Update: 2011-05-30