A load of 200 ohm is used to match 300 ohm transmission line to achieve SWR=1. Find out the required characteristic impedance of a quarter of a quarter wave transformer connected directly to the load.

A load of 200 ohm is used to match 300 ohm transmission line to achieve SWR=1. Find out the required characteristic impedance of a quarter of a quarter wave transformer connected directly to the load.

Solution :

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Description : How quarter wave transformer is used for impedance matching.

Answer : In all applications of transmission line, it is required that the load be matched to line, Which requires tuning out the unwanted load reactance and the transformation of resulting impedance to the required value ... Step down transformer If ZL <Zo then it acts as a Step up transformer

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Answer : reflection coefficient R=Vr/Vi i. There is no reflected voltage. i.e,Vr=0 R=0 SWR= 1+R/1-R=1 ii. Reflected voltage and incident voltage is equal. Vr=Vi; R=1 SWR= 1+R/1-R=1+1/1-1=infinity iii. If reflected ... and incident voltage =20V. Vr=10 and Vi=20 R=10/20=0.5 SWR= 1+R/1-R=1+.5/1-.5=3

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Description : The parameters of Transmission line are R = 50 Ω/ km, L= 1mH/km ,C = 0.1µf/km, G = 2µV/km. calculate characteristic impedance.

Answer : The parameters of Transmission line are R = 50 Ω/ km, L= 1mH/km ,C = 0.1µf/km, G = 2µV/km. calculate characteristic impedance.

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Answer : Properties of quarter wave transformer: 1. Impedance transfomation: it provides impedance transformation upto the highest frequencies and is compatible with transmission line. 2. Impedance inversion: if ZL is ... or step up transformer,depending on whether ZL IS greater than or less than ZO.

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Description : The standing wave ratio of a 75 Ω transmission line used to feed a 300 Ω resistive load will be _____.

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