{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

mid2+sol (1) - MIDT-EKM sanncn Midterm Exam 2 of-EElfil...

Info icon This preview shows pages 1–5. 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

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

View Full Document Right Arrow Icon
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: MIDT-EKM sanncn/ Midterm Exam 2 of-EElfil Fall, 2005 Name: Score: Problem #1. (25 points) Perfect Magnetic Conductor (PMC) is a counter-part of Perfect Electrical Conductor under the dual relationship of electric field and magnetic field. For PMC, it satisfies the boundary condition that the tangential magnetic field and normal electric field must equal to zero. For an air filled waveguide shown as below, the top and bottom of the waveguide 15 made of PEG, while the two sides are made of PMC The dimensions are a=5cm, b=3cm. (a) Find the dominant mode propagating in this waveguide? (b) If this waveguide supports TEM mode, what is the characteristic impedance? (1:) To keep the single-mode operation, how should one limit the operating frequency? (d) If the waveguide is completely filled with a medium with dielectric constant of 4, answer question (c) again. ' lie/tax PEC r) M‘s wavesfig’ql ads as a, ”fafw me |:|Ib @ :Flale mammal: M “‘3‘ a 0351, Us TE“ (a>bl ._ not -Wfi GED Charadefis’hb‘ ‘Wémqlf _ ‘ mefi ffi‘ (ODS MOALKS flwmlia a; ma 3’“ .. 33191 aeeihnfiwiamw ifs—Hm We 4'? . . .n _ w :1 Gla—_ s m can) in“ i 0 i ._ . a 3 11ng A _ ‘HW-r WW 3? 'Ttl: _. 13-“ :fir ll: lglxbiiD—l : are 6‘12 Problem #2. (25 Points) A rectangular wavegoide has a length a = 5cm and width b = 3cm. (1) Find the cutoff frequencies for the lowest four modes including both TM and TE modes and sort them in order (2) What is the phase constant ,6 , guiding wavelength 3. , the phase velocity vJ3 and group velocity vs for the dominant mode at 3.5 GHZ. (3) Consider a signal propagates along the waveguide with two frequency components at respectively 3.5GHz and 4.0 GHZ. They have the same phase at the excitation position; find out how much phase difference between these two components at the observation position which is about 5 cm away from the excitation plane. (4) If a lOns wide pulse modulated on a carrier of 5.5 GHz is transmitted in the waveguide, at what distance from the excitation plane you may observe two separate pulses? TE; 1%: c. :5on _ 361,: g 03' 92a; lxfixldl 3 " . -_£_ M;[email protected] *Ttoi ‘ 19C ‘- Zb F ls5xlofll __-\ t _ C i 5x103 . £66412® 1E” ‘ it" F I 5 xt_{_o:_,,__.,,. mush.“ _ _ racism” 1 W W 5 @ssaaa. XlO .._ I ,- 1,-2- 2) fifi/ Clmoawt MAL, u; 'lEfostéh—tm- <9 I) 61 3E gmf— {‘5 64cm S c“ : 5x10 .1 5.81,;{03 [rm/5. l- (in/18))" 0 .SIS 1 - g 1C"L 39:1)- : (5x10%)_ 'H:*_l.5‘l'§kl0 rel/36> I 3 5,811me ' ‘- Problem ii 3 (25 points) One needs to nude ctor devices. For example, if we excite a‘ particular waveguide mode'or mount semicondu ite the TEzl mode like in the insert a current probe into a rectangular waveguide to exc be is at the maximum B field in the following figure, we have to make sure the pro direction of probing. ' ' on the cross-section for one needs to insert the probe, assuming 1‘ y / probe Problem #4. (25 points) An air-filled rectangular cavity has a dimension a = 5 cm, b = 3 cm, d=5.5cm, (I) Find the lowest resonance frequency and mode of this cavity. (2) Find the resonant frequency again if the cavity is completely filled with a medium with dielectric constant s,=4 (3) What are the guide wavelengths for the above two cases. (4) If the cavity is filled partially with the same ”medium in Z direction to tune the resonant frequency as shown in the figure, from equal phase analysis, choose the minimum length we should fill in order to have a TE“. mode to resonate at 6GHz. hp”. LLE muWIml n. ma _ _ My? UMW 2%. n. L 3W m, u a. “a, WWII]! y? Mira”. fi ndwxw tnm,uim_. . mm 3.9 «W @241 poflwfléwfi 4 SWUmp ”PEI h Twin. 1%. F -5! fix? LEW 2‘ Q mp u. o. 3 033 ...
View Full Document

{[ snackBarMessage ]}