Figure 7-1 (p. 339) - Laboratório de Comunicações e...

Fundamentals of Electromagnetics With Engineering Applications by Stuart M. WentworthCopyright © 2005 by John Wiley & Sons. All rights reserved.

Figure 7-1 (p. 339) Non-TEM mmode waveguide structures include (a) rectangular waveguide, (b) circular waveguide., (c) dielectric slab waveguide, and (d) fiber optic waveguide.


Figure 7-2 (p. 340)Cross section of rectangular waveguide.


Figure 7-3 (p. 341)Location of modes relative to the dominant TE10 mode in standard rectangular waveguide where a = 2b.


Table 7-1 (p. 341)Some Standard Rectangular Waveguides


Figure 7-4 (p. 342)The field patterns and associated field intensities in a cross section of rectangular waveguide for (a) TE10 and (b) TE20. Solid lines indicate electric field; dashed lines are the magnetic field.


Figure 7-5 (p. 343)(a) A y-polarized TEM plane wave propagates in the +z direction. (b) Wavefront view of the propagating wave.


Figure 7-6 (p. 343)We take two identical y-polarized TEM waves, rotate one by +θ and the other by –θas shown in (a), and combine them in (b).


Figure 7-7 (p. 344)(a) Replacing adjacent zero field lines with conducting walls, we get an identical field pattern inside. (b) The u+ wavefronts for a supported propagation mode are shown for an arbitrary angle θ. (c) The velocity of the superposed fields, or group velocity, is uG.


Figure 7-8 (p. 347)Waveguide impedance of the TE11 and TM11 modes versus frequency for WR90.


Figure 7-9 (p. 349)Depiction of a microwave oven.


Figure 7-10a (p. 349)Detail of a magnetron: (a) vertical cross section, (b) horizontal cross section showing the conductive straps, and (c) the space-charge wheel.

(a)

(b)

(c)


Figure 7-11ab (p. 356)TM11 field distribution inside a rectangular waveguide. Adjacent to the left-column contour plots are conventional plots taken across the middle of the guide. The contour plot has been modified with heavier lines representing larger magnitudes.

(a)

(b)


Figure 7-11cd (p. 356)Continued.

(d)

(c)


Figure 7-11e (p. 356)Continued.

(e)


Figure 7-12 (p. 358)The TM11 Ez plots of MATLAB 7.2. This is a black and white rendition of plots that will appear in color when you run the program. The contour plot has been modified with heavier lines representing larger magnitudes.


Figure 7-13 (p. 360)TE10 field plots are constant in the ydirection.


Figure 7-14 (p. 362) (a) A wave incident at an angle θi from εr material to εr material (εr > εr1 2 1(b) A critical angle for θi is reached where the entire wave is reflected.

2).


Figure 7-15 (p. 363)(a) The wavefront for a supported propagation mode must have the same phase at points A and C. (b) An expanded view of the problem’s geometry.


Figure 7-16 (p. 365)(a) The dielectric waveguide TE modes for a 50-mm-thick dielectric of εr = 4 operating at 4.5 GHz. The bold line plots the value of the right side of (7.86) on the vertical axis against the angle. The other lines plot the value of the left side of (7.86) on the vertical axis versus angle for different values of m. (b) TE mode plots at m 0 for several different frequencies.


Figure 7-17 (p. 366)(a) The dielectric waveguide TM modes for a 50-mm-thick dielectric of εr = 4 operating at 4.5 GHz. The bold line plots the right side of (7.89) and the other lines are the left side for different values of m. (b) TE mode plots at m 0 for several different


Figure 7-18 (p. 367)Cross-sectional view of dielectric waveguide.


Figure 7-19 (p. 369)Ey field patterns for the first three TE modes of a 5-cm-thick dielectric guide (n = 2) in air. The dielectric extends from x = –0.025 m to x = +0.025 m.


Figure 7-20 (p. 370)Typical optical fiber consists of a core surrounded by cladding and sheathed in a protective jacket.


Figure 7-21 (p. 370)Cross section and index of refraction profile of a step=index fiber with rays for two propagating modes traced.


Table 7-2 (p. 371)Typical Characteristics of Glass Optical Fiber.


Figure 7-22 (p. 372)Expanded view of the cross section of an optical fiber at one end for determining the acceptance angle.


Figure 7-23 (p. 375)Typical attenuation in silica fiber with the three common usage bands indicated.


Figure 7-24 (p. 375)Graded-index fiber shown with a parabolic index profile.


Figure 7-25 (p. 376)Typical optical fiber communication.


Figure 7-26 (p. 376)(a) Forward-biased photodiode emits photons. (b) Simplified cross section of a Burrus surface-emitting diode.

(b)

(a)


Figure 7-27 (p. 377)Simplified cross section of a GaAs laser diode.


Table 7-3 (p. 378)Property Comparison for LEDs and Laser Diodes


Figure 7-28 (p. 379)Simplified cross section of a PIN photodiode.


Table 7-4 (p. 379)Comparison of Optical Detectors


Figure 7-29 (p. 380)Simplified view of a repeater.


Figure 7-30 (p. 380)Erbium-doped fiber amplifier.


Table 7-5 (p. 381)Typical Losses Associated with Connections


Figure 7-31 (p. 383)(a) In the return-to-zero data format, the first half of a period T is occupied by either a 1 or a 0. The pulse width tpw is measured across the pulse at half power.


Figure 7-32 (p. 383)A pulsed electrical signal modulating the light source (a) is distorted by the rise time of the optical source (b) and is further distorted by dispersion in the fiber (c) and finally by the rise time of the optical detector (d).

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Figure 7-1 (p. 339) - Laboratório de Comunicações e...

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