Prelim 1 - ECE 486 Prelim#1 Spring 2006 l(9 points An...

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 iconThis 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 #1 Spring 2006 l. (9 points) An airefilled rectangular waveguide with dimensions (Land 13 satisfying 1) < a, < 2b is to be used at 2 GHZ in the TEN) mode. If the operating frequency is to be at least 20% higher than the cutoff frequency and at least 20% lower than the cutofl3 of the next higher mode, a) Determine the acceptable ranges of values for a and b. b) For the values of a, and b With the smallest allowed ratio of (1/ I), find the wave phase velocity, guide wavelength, and impedance. 4' : M. M '1. K '1. r’N m. Q 2: Jk;3* EX ‘T “*9 .xl a + ‘ OM\M“ \ 0 O ‘ V1" war-\- IA 2- Ida“ 57. Tu“) éomw-OK'K 1' 42‘: a L/o... , he. “‘3"? \3 150‘ L ‘Fcr {k ‘— i ll "" "' K 2. 6H .9!- .1 z A I: 4 2’ b 0.23 6\. > 6" (M \a L. L CM fi.\$b hLAQL-h l‘ ‘ 'u: «at: an; EPY~§CM 5‘; ‘3 cm F: )«ZuF; v ___E'__.__—— 4’ : «7—,.- : r-iz ‘3 l . 2‘ u .. a “La/r? “9"" ’ “35 '3 (5 ) \ Z 5 3 (-6,?— 1 (M 1-3 c 3% r" a l 3“, 4 .,— I-‘(L (3?? 1L} era/e Q J______ 2. (8 points) A wave with a frequency of 200 MHZ propagates in a circular waveguide with a radius of 7 cm filled with distilled water (E = 8160). Note that this waveguide has somehow been specially constructed in such a way that TE modes cannot exist within it. a) Determine the mode that is propagating. b) What is the highest frequency wave that will excite only a single propagating mode in this waveguide? c) Write the expression for E3 or Hz (whichever is relevant) for the 200 MHZ wave. Make a sketch showing how the expression you wrote varies across the waveguide aperture. (1) Suppose the water is pumped out of the waveguide, leaving behind a vacuum. Will the 200 MHZ wave still propagate? Below are listed the ith zeros of Jn(:r) and Just), which may be useful. L... am) 420:) =1 11:2 n=0 n=1 n=2 5 IE 0 3:5 l=1 3.832 1.841 3054 1:2 5.520 .016 8.417 122 7.016 5.331 6.706 bx XW‘ , IGJ‘TM I» 2w T bk, c/Ct £°J""“o\ = ”‘2 Hr‘ra er- a. more nus‘r Tb'E THM a Lt) TM“ L‘ic Mu% b iJEWT "We ego-rah Hung Z sink-15% CI 6-}; d 3" (xai’: \ c2. lM\0§-T' ¢ dep l m 9° r \ 0k \ 3. (8 points) The electric field for a particular mode in an air—filled parallel-plate waveguide with a plate separation of 3 cm is given by: E41}, 2) : 106760“ sin(1007rz) kV/m a) What is this mode? b) What is the Operating frequency? 0) What is the highest order mode of the same type (TM or TE) that will propagate at this frequency? V1453cn~ e M g: Ex war-wit: Te Habfi 2 mar k=j=loofl =bv~=3 Mafia. 2 E 3:99“ 33:93?“ (56W3L= gooTFA-b __ LAT/4,1" C f 3 (EL n'fi' 51> TE. 115?, Pumnanfia m" .1 can...
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