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BOOK DETAILS

TITLE   : "ELECTROMAGNETICS WITH APPLICATIONS"
EDITION : FIFTH EDITION(INDIAN EDITION)
AUTHORS : JOHN KRAUS, DANIEL FLEISCH
PRINT   : THIRTEENTH REPRINT 2018
ISBN-13 : 978-0-07-070240-0
ISBN-13 : 0-07-070240-3
PUBLIC. : MC GRAW HILL EDUCATION

Considering page 141, viz. under chapter 3, "Transmission Lines", sub heading "The Terminated uniform transmission line and VSWR".

PROBLEM 3-4-2. Power Splitter. Referring to Fig. 3-15, two loads R1=300 Ω and R2 = 200 Ω are to be fed in phase from a 100 Ω line with R1 receiving twice the power of R2.

Find (a)l1 and Z1 and (b) l2 and Z2.

FIGURE 3-15

Here is my attempt,

$$ \frac{1}{100\angle0+z_1\angle{a_1}+300\angle0}=\frac{2}{100\angle0+z_2\angle{a_2}+200\angle0} $$

$$ {{100\angle0+z_2\angle{a_2}+200\angle0}}={{200\angle0+2z_1\angle{a_1}+600\angle0}} $$

$$ {\sqrt{{(300+z_2\cos{a_2})^2+(z_2\sin{a_2})^2}}}\angle{\arctan{\frac{z_2\sin{a_2}}{300+z_2\cos{a_2}}}}={\sqrt{{(800+2z_1\cos{a_1})^2+(2z_1\sin{a_1})^2}}}\angle{\arctan{\frac{2z_1\sin{a_1}}{800+2z_1\cos{a_1}}}} $$

$$ \text{On solving the angle and power part seperately} $$

$$ {\frac{z_2\sin{a_2}}{300+z_2\cos{a_2}}}={\frac{2z_1\sin{a_1}}{800+2z_1\cos{a_1}}} $$

$$ {{2z_1z_2\cos{a_1}\sin{a_2}}+{800z_2sina_2}}={{2z_1z_2\sin{a_1}\cos{a_2}}+{600z_1\sin{a_1}}} $$

$$ {2z_1z_2\sin{a_2-a_1}}={{600z_1\sin{a_1}}-{800z_2\sin{a_2}}} $$

or,

$$ {2z_1z_2\sin{a_1-a_2}}={{800z_2\sin{a_2}}-{600z_1\sin{a_1}}} $$

$$ \text{Now solving for magnitude,} $$

$$ {{(300+z_2\cos{a_2})^2+(z_2\sin{a_2})^2}}={{(800+2z_1\cos{a_1})^2+(2z_1\sin{a_1})^2}} $$

$${z_2^2+600z_2\cos{a_2}}={5500+3200z_1\cos{a_1}+4z_1^2} $$

Another attempt but different method,

$$\frac{1}{{100e^{j\cdot0}}+{z_1e^{j\cdot{a_1}}}+{300e^{j\cdot0}}}=\frac{2}{{100e^{j\cdot0}}+{z_2e^{j\cdot{a_2}}}+{200e^{j\cdot0}}}$$

$${{300e^{j\cdot0}}+{z_2e^{j\cdot{a_2}}}}={{800e^{j\cdot0}}+{2z_1e^{j\cdot{a_1}}}}$$

$${{z_2e^{j\cdot{a_2}}}-{2z_1e^{j\cdot{a_1}}}}={500e^{j\cdot0}}$$

After this I'm not trying. Either I don't know or too lazy. Posting answer is not worth if we don't know the solution.

  • Currently I have given up. I also did avoided the euler form. I have a book to complete, I will like to see others solve this. –  Mar 21 '23 at 05:53

0 Answers0