ps1_2011 - ECE 145a\/218A first problem set(basics of transmission lines and lumped elements Problem 1 A transmission line has 50 Ohms characteristic

# ps1_2011 - ECE 145a/218A first problem set(basics of...

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1 ECE 145a /218A first problem set (basics of transmission lines and lumped elements) Problem 1: A transmission line has 50 Ohms characteristic impedance and a load impedance of (a) 25 Ohms (b) 50 Ohms (c) 100 Ohms. Compute in each case the voltage reflection coefficient. Problem 2: lattice diagrams: Draw lattice diagrams for the 2 cases: (a/b) and (c/d), and draw clean plots of Vin, Vmid, and Vout. Case (a/b) logic gate with low (zero ohms) output impedance drives a 75 Ohm line of 5 cm length and 8 10 m/s propagation velocity. The equivalent circuit is in (b). The load impedance is 75 Ohms and Vgen is a 500 mV step- function. Case (c/d) logic gate with 75 ohms output impedance drives the same line The equivalent circuit is in (d). The load impedance is infinity and Vgen is a 500 mV step-function. Comment of on the relative utility of the 2 schemes for distributing logic signals using a transmission-line bus Problem 3: lumped-distributed relationships In all cases: o Z = 100 Ohms, = v l / = 1 ps, and gen V is a 1 V step-function.
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