ee713midterm

ee713midterm - ’E 1: «RED:- WT r v i \ \ MW 7:: = \ T‘...

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Unformatted text preview: ’E 1: «RED:- WT r v i \ \ MW 7:: = \ T‘ (U17, j) S‘ 4:30: (900 mu»: A k x 'n‘ ‘AM&&¥ 'Qufié a?“ U x ; Kr- I L ( t a m \\ (1+1; 93w WDW‘W W¢$..2m;.._ 'J‘ijjkfiw ~ \ \ ". ~ ¥\ 1 UT“ ‘9.» —9‘ gr”: V Q\b rs», \ . ' - - WW m l. ~~~w ~ ,, . . , 7 ~ ; mam—v. ,7 " W - ( \ 4 «if < mm- \muu‘ am --> \we‘w mmA-M ML kmwfi ‘61 \V “WWW (C) 03.9% A)“ (wk-5”} Qua ( LLVJ‘, . A 2. ‘ W |. Y»: WE’A- 93:?— .-~ "‘7 + NS ’- (onv-f‘vfi‘ PM < v 4—;- A T”, "4 ‘ V5 7 ’3‘ (“at-3A} 3716) v “i = omfi mm -= 3H ° 0/” (Qémfixrcca ._..—v—--- E \(‘J‘Q‘VKM 5} 6H%/ “(1: gg° ‘ .x; . m, .‘mur- :ra‘r (a3; (mm 3* Q5er 9. m A- A» «3‘9 1‘ 4’“ *U‘W‘ “w‘m‘ “ 1&9" “9910‘ K “- OAKS. I V N1} “314 '1 dLCQAfiC‘D‘. as.) A» I.” ‘6 \ 8\\ [Ni/Z"; .2 _l ‘fikasv *1,"M‘\_; ofl}vh+ \§\ 9) ix} r ‘ ‘2 ( .R¢mmawwwwfiwfiuz%.¥ &WW~C . = “a rum, m: I ) T»\\§xg. ( ‘ r P‘T' ., / I [M‘wa H va‘fi \ry‘f‘u?‘ “ ’3 A: r L r ‘ \ W“W%w%¢~wu&\ L‘ l I, *r' \‘J L») 3L0"? EL") %(DA E— _f_ ‘7‘“: HQ“: p.183 d~~h,. D, 94mg, YA?“ ‘U "N BB 713 - Spring Quarter 2004 Final Exam June 7th, 2004 Write your name below and sign the honor pledge “No aid given, received, or observed” if it applies. There are 3 problems on this exam. Exam is open book and notes. Please box or underline your final answers, and remember to include units. Be sure to show all work clearly if you wish to obtain any partial credit. Try to keep your work within the provided space. Use the back of a previous sheet if necessary. Name: No aid given, received, or observed. “The Pledge”: BMW A 1 GHz transmitter is located 40 m above the leftmost point on the terrain profile shown on the next page. A like-polarized receiver is located at the rightmost point on the profile (52 km away), and the propagation loss relative to free Space is measured as the receiver height is increased from ground level. (a) What is the lowest receiver height for which a free space propagation level should be obtained . _ 4 . A lfk — —?(15p01nts) X: - .32. eff 3 _ . . , ML ~36~3‘ k \J P»; .. va “rm, t: be i M _ :33: ~39 am (\\&‘4\* 6*." i; ‘fi ‘3 , nut-k, 1(3 $bok~ mm R; hm P‘, « a NEW») L —3 . _. , 3‘,“ 0 w 1-. ‘5'?me “ H D M '64 “‘1 , “Li” R r ;. ' ‘ ‘ «U h A \er ‘v , $013433 ‘5 Y'Klbg a 33b A “\u‘ V ‘ sum? "‘ “‘ W1 is“; (b) What is the lowest receiver height for which a minimum in the height gain pattern would be ‘ obtained if k eff = g assuming the point at distance 36 km is the only reflection point? (15 points) g3“ SM) +33. Q1- ,Lq)) ’ W r ‘ 1 T _ .__:[_. T._j.__. _LJ_L14_ I l l _LJ_Li4_L4_ _ g. .1 51.. 1-4 Inlclllllllllll. I .._.'_._I._ ._|_.1‘_ L4_L4_ 4 81216202428323640444852 in. _ 1|._I 0000000,OO\OOO 0 6 2 8 4 0 6 8 4 0 7 6 6 5 5 5 4 4 3 3 3 EV _m>m_ mmm m>onm 29m: Emtmz. Distance (km) Problem 1 (cont’d) (c) If the effective Earth radius multiplier is changed to keff = g, would your answer for part (b) become larger or smaller? Explain; it is not necessary to find the receiver height obtained for this case. (5 points). ken-9'13 Male, \0 \‘fX—r s» MW lawm\m. \DQNKAO/ Voca- ago-uh: 0 0 0 0 0 0 5 0 5 0 5 2 1 1 0 w 2 E5 292.. 8:8sz 33:5 400 350 m b m P IS I m W .m M $ 8 d b .b. e . t H .m A m m 5 m m m. H m. o 5 .m m .m 6 m m a 4"\_n_/ my W m. H o e 2W m m M “w .s 0 .n .m— d 39 0 H .0 U f. m d g m e 39 m t r v m F m m m 3a m. H .nlv e .H .m 2% w W W 2 m m. w 2 o m r H m. 8. P W m 1 .m. W r 4. m w w 1 d 0 .0 n_u mu 0 0 n 0 5 0 m 1 m 3 2 2 "m m 5 :m m m a e a, m 0 .1 n M» .w o P m A and assume a planar Earth. P Electron densitv (#/m3) (a) Find electron density values N1 and N 2 to make this electron density profile consistent with the given ionogram for the ordinary wave. Note the charge and mass of an electron are 1.6 x10’19 c and 9.1 x10‘31 kg, and so = 8.854 x 10'12 F/m. (15 points). 0"an W nil-W) win Kt} -.= ‘5”: 1. L m a $1, W” 7. 6d: (Arvin 9h?“ . w.“ CM 4% a 65““ LA (“A-L, “Ash Gd? ~"\ was: 3-» ~ S.’\- MHlu an. \A\wo.‘\-lrt Mn GW*‘\\L.\J m Mai-gt” ‘nka N‘ f 8w? w w w- w: 12" W >“ wsz N _ Ltv‘QUwD‘L 1‘ z s “ 314W 3"” fix" Aiillpi 3138c ‘3 in“ A series of transmission curves for fixed oblique operating frequency f o b = 12 MHz but varying path distances D are now overlaid on the ionogram as shown below. 400 4 350:}. ..... ...... ..... ...... ...... ..... ...... ..... ..... ...... ..... . . . . . . . . i . . . . . . , . . . . . . . . . . . . . . l l 4 l . . . . . . . . i . i . l l . . . . . l l l . - . . . . l . . . . . . . - . . . i . . I . . . . . . . . . . . i x . l N 01 O —L 01 0 Virtual Reflection Height (km) 8 B O O 1 1.4 1.8 2.2 2.6_ 3 3.4 3.8 4.2 4.6 5 5.4 5.8 E)? “\ka Vertical Frequency (MHz) (blhndthe skip distance for this case. (10 points) ChaAvg‘Fbr W 03/ \1l‘\\'\t is 5695:!» Qua—W Mgpl For \pmthW-fi “’0 V‘Mkk‘:m NV D1afllv¥h 4, (MA? 159 ‘5" C/‘ 4k? $0M» \PU'L- (kn {sk‘wa‘s‘f’h Nam. 3.2, \w\¢L’5—§'oz ck Mxmn com-40w W-‘lw~§_ W pvi‘éc " h D (c) Find an angle 6, that can be used to communicate over a 1100 km path at 12 MHz. (10 points) 594,61 :- Sgt V II WOSU-AM operates at 82% 3H2 and broadcasts 5 kW of power from a short vertical dipole antenna on the ground. The entral Ohio region can be modeled as having an average efl‘ective conductivity of 12 millimhos and an effective dielectric constant of 5. (a) Find the distance in km within which the planar Earth groundwave theory is applicable for pre- dicting the signal strength of this station. (5 points) : &b I A K (:‘O I, ‘- Ayn ['5 n {0-31}, $ - L‘ QNQQXM (b) Find the planar Earth “numerical distance” Wagon at a distance of 50 km. (10 points) \1— “5- *Wluexh’) A b‘ - V P‘- —3 iv: (-4 c it???“ ‘0‘°m\ Q -:*~ 6‘— 5— 3 5; 6 J: N bre§ .c l N ,3 9: ‘isco‘bfigbbx‘fi’v Lt: us En g: M @3243) 03%; N < @ngfimwl) -: i ‘ S ~3 Qtz ct ' ‘3 (o mam m \ / \IM «3qu I" 1L3 ~o 1. e“ "Le—J \ " .0 - I J 3 an“ m5 in \ “2‘ (c) Find the groundwave electric field amplitude received y a ve 'cal antenna on the ground at distance 50 km. Use any figures or approximations fi‘om the notes as necessary. Note for the spec- ified transmit antenna, 2Eo = 300.5 millivolts for distances specified in km. (15 points) “N [3% mi, N uh “a “3 X“ b*— L] J “:1. X s l W “I, I K :9 A J XiY i: 3/)!“ NJ ...
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ee713midterm - ’E 1: «RED:- WT r v i \ \ MW 7:: = \ T‘...

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