PROBLEMS

PROBLEMS

(1) Apply Smith chart to get the following line parameters if the reflection coefficient of the load is 0.4< -46 and the characteristic of the transmission line is 50Ω.

(2) The following lossy transmission line has a characteristic impedance of 50Ω and is terminated with a horn antenna ZL = 12 + j25 Ω. Illustrate by using Smith Chart, how to determine the parameters shown on the transmission line, in oder to match the transmission line with parallel connected stub.

(3) To ensure an optimum transmission of a signal, the impedance of a transmitted

antenna must be as close as to the characteristic impedance of the transmission line

Zo. As a trainee technician in Telco Sdn. Bhd, you are assigned to determine the VSWR

Ydstub1

Dstub1

Ystub1

YL

Lstub1

produced in this 50 Ω communication system. The antenna is a parabolic antenna with normalized admittance YL’= 0.3 + j 0.6. Then, using the same Smith Chart, you need to investigate how to match the antenna to the system by using a single closed-

circuit stub which is connected in parallel to the transmission line. Your answer must

include TWO (2) possible stub positions and the designated stub lengths.