Lab 7 - Solutions

# Lab 7 - Solutions - EE 330 Lab#7 Solution Spring 2007 The...

This preview shows pages 1–2. Sign up to view the full content.

EE 330 Lab #7 Spring 2007 Solution The Big Game on Cable TV 1. How far down the line can you expect to find the problem? 8 8 10 49 . 2 10 3 83 . 0 % 83 × = × × = = c v m/s 6 10 1 . 12 × = τ s This is the travel time to and back from the point on the line where the problem is, thus the problem is expected to has occurred at about Ft 4 . 4942 m 45 . 1506 2 = = v from the distribution box. The accuracy, with which the TDR device measures distances of the this order, is . Hence, the problem is m 35 . 3 Ft 11 = m 35 . 3 45 . 1506 ± from the distribution box. 2. How many dB of loss would you expect to see in kilometer of cable? At 50 MHz, the loss is dB/km 52 dB/100m 2 . 5 = ; at 100 MHz, it is . Assuming linear dependence and interpolating, the loss at 67.25 MHz is expected to be dB/km 72 dB/100m 2 . 7 = () dB/km 9 . 58 50 25 . 67 50 100 52 72 52 = + 3. How far back from the slice (toward the generator) you need to place the stub? m 7 . 3 = = f v λ The normalized impedance at the point of measurement is Ω + = + = = 4 2 75 300 150 j j Z Z z c L L , marked with a blue dot on the Smith chart. The corresponding admittance is 1 2 . 0 1 . 0 4 2 1 Ω = + = j j y L , marked with a red dot. The stub must be connected to the TL at a point where the admittance, y d , has a real part equal to one. There are two green points on the Smith chart, which correspond to the two options, 9 . 2 1 1 j jb y d ± = ± = The point representing the admittance with the positive imaginary part is closer to the measured admittance, y L , a normalized distance of 234 . 0 202 . 0 468 . 0 5 . 0 = + = d back from the slice. This normalized distance is denoted by the red ark on the Smith chart. The actual distance is cm 6 . 86 m 866 . 0 234 . 0 = = = d .

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 5

Lab 7 - Solutions - EE 330 Lab#7 Solution Spring 2007 The...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online