Prelim 2 - ECE 486 PRELIM#2 SPRING 2006 1(9 points Suppose...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Image of page 1

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

View Full Document Right Arrow Icon
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ECE 486 PRELIM #2 SPRING 2006 1. (9 points) Suppose we have a dielectric slab waveguide with thickness d: 1.0 mm surrounded by air on both sides. Take ed = 260, Jud = #0: and assume the wave frequency to be 350 GHZ. a) What modes propagate in the guide? b} For the lowest order TE mode, graph the two curves that a: and 5% must satisfy. c) Estimate am fix, and then the wave phase velocity in the z—direction and compare it quantitatively to the intrinsic wave phase velocity in the air and dielectric {the intrinsic wave velocities in unbounded media}. d) What is the highest frequency that can be used with this guide without exciting multiple propa— gating modes? («.4 0x Q: a We. ’ We Melon} m: DH?! nous: WWI:— ”yd/z ‘9 n if}: ”It; "" 4.4/1 “ A; "k“ —:;: 6‘ h“ *4" 4‘“ “‘“L “FM w \ a "' 1 “5—C\ r(3-6¢\ é-F'usc-k‘sohc. 'FBI' fly 33-1/1 Bg-Vz. 3-". ha“! in M“ J-‘f‘vf "z“ 3-YC 1-3.5 C. d): capo (W {ll (by: was TTT ‘1 4 rs: 4‘ * ”/61.- l ,filb M J0 r w/fl) : 2.1km M’s c > _.._.. c 3. 04, M I"; (at M :5 ISO age-t (rut M00668 1 ”"5 W "15. 7". BOTH Eran-'63:» Rf" aw) mangaa/ 2. (8 points) The Arecibo S—band radar transmitter operates at 2.38 GHZ with a peak power of 2 MW. Evaluate the idea of using a 500—In long section of aluminum waveguide (CrC = 3.54 X10T S / In) to deliver power from the transmitter to the antenna. Consider using a rectangular waveguide with dimensions 10 x 5 cm to carry the T1310 mode. a) If we desire single mode propagation, is this waveguide suitable for this operating frequency? 13) Determine the loss, in dB, for the signal passing through the waveguide. Neglect dielectric losses. Is the loss significant? c) Suppose we want to transmit pulses with a pulse length of 6.66 ns Wraith-0W) Will the effects of dispersion be significant? (1) Calculate the maximum power handling capability of the waveguide, given that the breakdown field of moist air is 15 kV/ cm. Can the waveguide handle the required power? G A Sew = a: 1.5 cpl-,5, my Ln!» 1». org my (2\ c, 1:30, .= 11-: 3 («H-:5 6" r 'F‘Izo Ir-FM. . a“ 0— WF") '7‘ W W ‘05'3- 0.02} I'll czar 4.5-2, e : r. : 0-2:] : -c.n an gain swans (1] .J—..J- ._ a— 7 c. M“ ac‘iy Vat-\' 2;? (%;'"m\ 5.: ‘C 5")" “g. F 15b MW! It 1, 9 C.- V on .33:— (hsr'falxcsl g a.“ as 7 so M!) 14’ n.1,; as 3. (8 points) Consider a step index optical fiber of silica cladding 0121.500) outside a SiOg core fiber (n21.504) of 10 ,um diameter. a} Suppose you do not want to excite the 91 = 2 axisymmetric modes in the fiber. Calculate the highest frequency that can be used. State your answer in terms of optical wavelength. b) Using a frequency 40% that found in part (a), find the effective index of refraction and estimate the phase and group velocity for the HEM mode in the fiber. The graph provided may be helpful here. c) From the points of View of dispersion and lossiness, is the mode you found in (b) a good choice for long distance, high bandwidth communications? Below are listed the 5th zeros of JD (3:), which may be useful. J0(zc) 1:1 1:2 1:3 2.405 5.520 8.554 a. $47., «fa: 1E: “ue‘M‘ g '1 s D. 613M (L\ a. mu.» run-2,1, '>~ar l—SS/K U\ stop: «I 0.»: “Lu...— "’ "51’: f‘ \ U4, .- 39.“ x L 44-1 mo" Ms, (‘3 taupe; 3 $6; 1,: " fit Va z {"74 ”w" ”/3 0 \ ...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern