This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: ECE 3025—
mm. EXAM 1 Sou/“Wows —/=/+LL 20/0 Problem 1. (25 points) Consider the following circuit. At a time of t = — 00 the switch is placed in position A. At a time of t = 0 the switch
is placed in position B. 50 S. 20 V J. B
50 Q 2,, = 90 9.
Transit time = T Fill in the reﬂection diagram on the next page for the time interval 0 S t 5 4T. A. Calculate and write a numerical value for the reﬂection coefficient at the generator end of the line after the 3 P113
switch is connected to position B. B. Calculate and write a numerical value for the reflection coefﬁcient at the load end of the line. 3 ? l S 15% C. Calculate and write in numerical values for voltage states V0. V1, and V3. D. Calculate and write numerical values of the voltage amplitudes for waves V1+, v2", V3+ and V4‘.
E. Calculate and write a numerical value for the eventual steady state voltage V55. 4 P TS Only answers clearly written in the text box fields on the reflection diagram will be graded. Use the space below for your calculations and a graph page is included if you desire to do this problem using the
graphical method. t. tot—KEN SUJW'CAA A \s CLosﬁ—D + >> IOT ‘0\ USF« Ves +0 661’ Vs; BUT 6&1 Vs;— FH'LsT— Frlorvx cum/UH" 40
4. (it.
V55 1 96/55 ( Qek%v> 2V; @29} V5
VJ — \lgé( Ear $0
'2. g  p. +HEAIEMIN EszthALENT' anacon
4, F012. LoA‘b SlDE AFT'ER
Ves ; 990% zen—ac v sraAW grATﬁ
2 2‘3 4.
V“ . l§.%'S‘i vow—s
BUT + '
VSS 3 Ves '4’V65 September 22, 2010 ECE 3025C Exam #1 Name: t< E. Y Problem 1. (Continued) Fill in the Reﬂection Diagram for t > 0 AFTER >> [OT t Vssg 0
0,0 MPLETE Discwreb E A A F" : Ke—%o : go—Cio = _O.2,gé_
G 'EG—J" b SOHO V l, * (“'5 = ”540 —. 0393
{ain’t—b z§+qo Frail?
CALCULATE vI 3 VOLTAGE STA—TE AT (35M, S‘DE— A .TH
suuvrcu Eb To E; US[MG 1HevEMtM €62. CIRCUIT 60 V5; FMM $1'EP it A 523
40 V. 2 7416; ((53:30 : Z($.éé7)[§—B’+—71o A273
\/'{S—o RE— September 22, 2010 Name: K E Y Problem 1. (Continued) Graph paper for solving Problem 1 using the graphical method ﬁrms LUA$ OPTIONAL. METHOD ”7"”? 5 u , +2 QDCWUS pas 19: Panama»
» 7P ‘ 1M Ammo» To NUMERICAL 209 11% ' épwrmo) (IF Bow £921,154”)
} 159 I
‘ * \NtTaPsL. QWE / ‘\
’ *1'0‘v; PAT 1+ mnmgmpﬂeuY
Ame. , . 5a: 1Tc QED OVA ,» <4 vI
{"in ‘ gm \TCWE'b alt—o B ,, ., .iém? :,.,} i:
SLOPE ”4 ou—ms 5‘” Re —§'o
Ea —So b\$C,HAR6/UG LINE. coals/Ur p49“);
FROM IQth—l'r ‘(o LeF‘r 20 +90 were“ wAuE A/thuEs AT LOAD
. A
«2,, «Q0 wuau acme. Aamues OFF 8;, 02 26. September 22, 2010 4 ECE 3025C Exam #1 NW KEY Additional Work Space: (Identify the problem for which you are providing the work) 6mm udé— Moves PQDB. 2
camp—c? REFLECTION buw/MM 497': I; 2.st F waE FACTOR,
Q, 3PT$ TR (mm goamio‘r VowMia 3W5
DIULDE FACTOR Vss CHECK—ED To £UENT’W‘rL V55 UALUES Fa/Z. LJIUE / 3107‘s
AND LIA/£2) on HUG/1644790 awsa /ao/2/25c7‘ mug/015K September 22, 2010 12 ECE 3025C Exam #1 Name: _L< EL Problem 2. (25 points)
Consider the following circuit which consists of two lossless transmission lines joined at an intermediate junction with the resistor R J placed between the lines. The propagation time in both line 1 and line 2 is T . Values for the cable
impedances, generator resistor, and load resistor are listed. {261129 50 9 Line 1 R}: 50 5. Line 2 r1 : KL.— %0 2 202 = 75 9
Transit time = T Fill in the reﬂection diagram for this problem on the form provided below. Fill in all wave components and voltage
states through a time of 6T, i.e., carefully label the voltages of all wave components and the voltage states for distinct
regions of the reﬂection diagram. Only voltage values are requested, i.e., you may omit current values. Show all
calculations leading to the reﬂection and transmission parameters that you use to receive full credit. Hint: Check your voltage states after 6T 0n the reﬂection diagram to the eventual steady state voltage values
for,(a) the voltage at the left side of Line 1, and (b) the right side of Line 2. Note that these voltages are not
equal because ofthe resistor placed between the lines. L):§\y/
Z. Vssl =Vg( QJHZ” , lot “’9 );(oCé7wcrs if [2: “2
Vsslmb: YA W> Line 1 > Line 2 52: HS +50 HS’
{=— 0.4126 F __V ﬁj+£i “202.
lZf+£¢t 452:0; 1—1 77:1. ‘Tl \ p /\/ 237.47% '
,7 :(lﬁ’Z/QéXﬁ) = 0’95 7/ {565 NEXT p/réré)
5 September 22, 2010 ECE 3025C Exam #1 Name: J<‘E Y Additional Work Space: (Identify the problem for which you are providing the work) 10/2052. coUT/NUED
1’#U$) VJ 77:2 p125 MJZ=\/,j7;::(g)(0 357/) = £71.22é VooTS 0AM; T/Zfr/Ué/n/éélcnk/ dag/a: Fw/M L/A/E 2
6mm /N7'o LINE ,1. 7; ::('+IZ>(—Z:£ik;) (1/5’29’) 55:57)) / m:@,g7lg as; 7145 nﬁoUE ”fa meLErE 77%":
EEFLEoT/ou DIAéJiA/M NOTE 77+A7' AFT/i/L 67‘ EACH SIDE
(s wl—rH/A/ ~0.oo3 Y'OF EVE/VTU/‘tb/ do/ULFLCT STEADY smrE 1/0/7495 VALUES
ng/ué Pom/7' D/sfﬂ/BUT/a/t/ com/éEoT leé—fLPr/M 1/ p73 (2 > [2 J2 J2 EACH 3W5) xzﬁvT/‘N 7‘7!) 7‘7; sz7+ P/ZWE/Z— 3 574424
VouméE. Did/DE FMT’O/as é 7’07’ﬁC Cort/e EOT 51’5th 67177.2 5 VOLY’HGE VALUES 0?
CHECKED 72; eo/eagcf V4405 September 22, 2010 12 ECE 3025C Exam #1 W K '5‘!” Problem 3. (25 points) connected to a lossless transmission line. R515 a voltage source VG
d at the right side of the he line impedance. A nonlinear load 15 locate
t is as beside the load ZL Consider the following circuit which consists of the output impedance of the generator, and Z0 is t
line, where the relationship between voltage and curren RG = 25 ohms Z L = Nonlinear Load V: 40013 ; I S 0.15 amps VG : 10 V :— V= 9 volts;1}0015 amps Fill in the plot on the next page to clearly and accurately show: . The current ~ voltage path for the nonlinear load. A
B. The discharge line for the generator resistor R0.
C All the charge/discharge paths for the transmission line through a time of 3T, where T is the one—way propagation time in the transmission line.
D. The eventual steady state voltage and current across the nonlinear load. Use the space below for your calculations. . Hint: Calculate the voltage states along the nonlinear load at current increments of 0.025 A from 0 to 0.25 A,
then draw straight line segments between these points for part A of this problem. Gamma/é ppm/7‘ D/sTICIBUT/OA/
A, PLoTv'Eb {LL/NB. amend“ 5PTS B, PLO/775D £6 Cog/25671,)“ 5107's C PLorr D
E aim/EéZéZ’CZ’F/D/SCHM‘E /0p7‘s D. ,QEPLSO/Uﬂ GU? VﬂLz/E 13/2. S S
VOLT/9'65 AM/ZKED 0w p407, MID Girl/E NUMB/Z/Qgg, 041.45 5/0“ September 22, 2010 6 ECE 3025C Exam #1 Name: KE Y Problem 3. (Continued) “7.5V _ , ,, M: ., 3,, g ,V : 3:“ ”V ;,., x . \. WW Vim
: “:5sz M3,; 45, I. ,. :4 w \. Cwﬂ, , , \ ”Mpg,“ V H, A «» .wm \ V
;‘ r f; L
‘I)\/ Pom/7’s poi Eb):V=¢/ooI V= 9vo¢T$51>o.rsA
1M} VCUOLTSB 0.083 0.25
000? [,0 00075 ’2..ng ZS‘JIGEl/EMTOK Lava ; i A: =— o./6A:‘> Av :§’WL7’.<.
4017.2014/‘15: Av: Iov :5 AI: = 0. (HA (6431165)
. Av = ,W .—_> Ar = ’od/IMDlSCf/ﬁ'ﬁéli) September 22, 2010 7 ECE 3025C Exam #1 Name: KE I Problem 4. (25 points) Consider the following circuit which consists of a voltage source VG = 10 volts connected to a lossless transmission
line, where R6 is the output impedance of the generator, and Z, is the line impedance. Assume that R5 = 29 = 50 ohms, and that the switch is thrown to connect the transmission line to R0 at a time of t = 0. 20 = 50 ohms
R6 = 50 ohms Transit Time = T = 1 ps The values for the load at the right side of the line, ZL, is shown in parts A — E for several different cases. These
include simple resistor loads and some reactive loads. Assume that T = 1 us is the one way propagation time for the
transmission line. For each case, sketch the corr eform versus time for each of various load cases through 4T = 4 us, and following details must be c arly and explicitly shown on the plots: voltage levels vs. time for all problems, and
.ter plotted decay rates for the reactive load problems. Use the blank sheet after this September 22, 2010 8 ECE 3025C Exam #1 .KEY Problem 4. (Continued) Name: 50 o g PT‘S’ m
I! B. The load is a resistance of 50 ohms connected to ground: 10v 5v , Na
{/2‘5 LEQ‘MM Fd’ZF: a C. The load is a resistance of 100 ohms connected to ground: v m
541 September 22, 2010 a 9 ECE 3025C Exam #1 Name: (E Y
 P bl 4. (C t' d) 0.001 F P
ro em on mue "lI—E b P 7.;
1000 D. The load is a 0.001 pF capacitor in series with 100 ohms connected to ground: g
_ L "10m 5.; it‘w THE/V EXPOMFNV/ﬁécy
KISES 7‘0 /0V 7" (20+?)C 72:0 30 )(0 col)
7%, 0 ~ / S/ves 6v «glow ‘ s f . , . ,, lopH E. The load is a 10 pH inductor in series with 50 ohms connected to ground: = $50 0 5/ / S > 10?,
5v
. "0“V ”45v September 22, 2010 10  ECE 3025C Exam #1 ...
View
Full Document
 Spring '08
 CITRIN

Click to edit the document details