Question

a. A 50 air-filled transmission line is working at 3 MHz on a length of 5.21. The line is terminated with a load impedance of ZĽ = 40 + j25 12. Evaluate: i. VSWR using both Smith Chart and equation. Compare both answers. (CO3: P04 - 3 marks) ii. Reflection coefficient at the load using both Smith Chart and equation. Compare both answers. (CO3: P04 - 3 marks) iii. Input impedance and input admittance using the Smith Chart. (CO3: PO4 - 4 marks) b. An antenna having an impedance of ZL = (50 +0100) is connected to a 50 22 line. Evaluate the position and length of a short-circuited stub designed to match this load to the line. (CO3: P04 - 15 Marks) (Note: You must utilize Smith Chart for both questions and show all the steps accordingly).

Answer 1

7 Given Zo = rod f - 3mine I= 5.2.4 Z=140 + 25) v swt thg a reflection coefficient VSWR = Itti 1.-TI Ia Zi-Zo. 40+125-50 Zitze 40+j35 +50 -10+jus 90+35 = -0+j35 C 90-32 got 125 (go/25] -goo +250 + j2250 + 625 (go)2 + (272 -275+C5ooj 8925 -0.03151 +10-2865 10:288 / 96.27° TSWR To 288 1-0289 VSWRE 1.3 By smith tiart! load CI) plot normalised impedenel on smith chart 2 40+125 ب2 zo 60 20.8 + 10:5

" 1 TTTTTTT111 TL 4, losse The Complete Smith Chart Black Magic Design . 011 HU 4 014 1 0.72 134 ), om 11 0.01 10.6 IT 3 0,0 042 120 y 18 00 0.41 8 $ 190 eiro 18 011 140 12 2.1 co 045 100 P اکی vo X IL N + 1 11------ MONENT (+X70, OR CAPACITIVE SUXEITANCE(/Yol 70 H----750 PEX COEFF 011 07 $ 23 19 ANCE COMPONEN 0.2 ( zio MO RADIALLY SCALED PARAMETERS TOWARD LOAD -> <-TOWARD CENERATOR *10040 20 10 12.01. - ---- -- H. 1.1 x 40 301 15 20 1.2 1.6 1.8 2 13 14 10 20 0.1 0.2 0.4 0.6 0.8 Tinti-11.2,14-11-12, 15 rrrrrrr i 0.9 0.8 0.7 0.6 0.3 0.01 0.2 0.5 0.10005 WO 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 (1 0,8 09509 1............................ LAS 0.5 LALU 0746 04.0.3.02.41.0 CENTER 02.02.04.LOS...06. 1.8 1:12 ORIGIN 5 ZIN 100 O- vo a 203 ra Mo 610 B 160 0" 81 -50 0.15 0.07 0.43 9 210 0.42 10 Ye ackling 190 0.1 to 1 SID SLO 0,4 CED 60 L- S-1.84 110P ot OPIS:07 NIA yu ly HOTTO بليييييييييييليين ITIE = 0.28

Normalised 눞 (viii) Disitan el blir Zmay to Y2 un clockwise i Load impedence zia 2/20 50 ftoo K d. 507 z = 50 titoo procedure si plot normalized lowed impedenie zon Smith chart (ii) braw unit cirele with centre: (310) cil Drave usor circle. (lol and radius of distince blu Centre Clo) and z point (v) plot ý It is opporite diametric point of a ( plot y point of intersection with uwit circle where viwr cirele meets on this point [grZ y 1+2 (vi) Distance blue ÿ L and clockwise direction (vii) plot Y2 Ing Ly12 4 - j2 dolgt torso. Wy) d = 0.75 I = (0.312 -0.25 JA ac obla

ko . ENT (+1X/ZO), OR CAPACIVE SUSCEPTANCE (B/YOL CAPACTIVE REACIANCE COMPONENT 1X / Zo ) . OR INDUCTIVE SUSC D o' 1 Et th The Complete Smith Chart Black Magic Design 07.12 0.11 0.13 0.14 0.37 0.36 09.39 100 L 06 0.1 0.4 110 1.15 0.35 0.149 es 040 0.16 0.34 70 0.09 0.17 5 0.42 120 60) 0.33 O/ 0.07 0.43 +----- mu 918 23 0.2 OCT 0.32 50 Lika 2 st 0.44 -> 70 0.31 140 0.95 40 post ON 10.6 OMIC KIM U CS K C 08 2 0.28 X 0.61 INGLE OF to 0.23771 NGLE OF 17 II 0.24 1.4 U Sual b OMPONENT (R/Zo), UCTAN COMPONENT TC EFFICIENT 5.4 TYPES DECREES D.D TT 10 15 08 03 ti 091 62- yo 0.05 0.45 -140 '0' 03 l 0 ALE -1.30 0.07 So. 02 0.43 -50 0.18 120 01.08 no 5 to be 0.17 011- ཡ་ཡི་མེ་ EO e . 0.41 0.1 -100 0.12 0.16 0.31 -90 0.4 0.15 0.35 0.12 0.13 0.14 60 +++ 0.38 0.36 0.37