Electromagnetic Waves and Antennas combined - Chapter 22 doc

... dB.  22. 7 Hall ´ en Equations for Coupled Antennas In Sects. 22. 4 and 22. 5, we developed the Hall ´ en-Pocklington equations for coupled an- tennas, that is, Eqs. (22. 4.8)– (22. 4.9) and (22. 5.1). ... Fig. 22. 3.1. Their distance along the x-direction is d and their centers are offset by b along the z-direction. Fig. 22. 3.1 Parallel linear dipoles. If antenna-1 is driven...

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... Quarter-wave phase-shifted fiber Bragg grating. Quarter-wave phase-shifted FBGs are similar to the Fabry-Perot resonators discussed in Sec. 6.5. Improved designs having narrow and flat transmission bands ... already first-order, the multiple reflection terms in the above summations are a second-order effect, and only the lowest terms will con- tribute, that is, the term m = 1 for the near-end...

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... as (a) quarter-wavelength single- and multi-section transformers; (b) two-section series impedance transformers; (c) single, double, and triple stub tuners; and (d) L-section lumped-parameter reactive ... [978,979]. Possible applications are the matching of dual-band antennas operating in the cellu- lar/PCS, GSM/DCS, WLAN, GPS, and ISM bands, and other dual-band RF applications fo...

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... diffint(0,sb,0)); va = hband(sa,1); % 3-dB bandedge for H-plane pattern vb = hband(sb,0); % 3-dB bandedge for E-plane pattern The mainlobes become wider as σ a and σ b increase. The 3-dB bandedges corre- sponding ... Reflector Antennas Reflector antennas are characterized by very high gains (30 dB and higher) and narrow main beams. They are widely used in satellite and line-of-sight...

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... antennas being synchronized with atomic frequency standards, and then the recorded signals are digitally cross-correlated and processed off-line. The achievable resolution is about one milli-arc-second. We ... graphs: sigma=1e-3; ep0=8.854e-12; er=15; f=1e6; h = 1/4; n2 = er - j*sigma/ep0/2/pi/f; th = linspace(0,pi/2,301); c =cos(th); s2 = sin(th).^2; rho = (sqrt(n2-s2) - n2*c)....

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... windowing 3. Woodward-Lawson frequency-sampling design 4. Narrow-beam low-sidelobe design methods 5. Multi-beam array design Next, we establish some common notation. One-dimensional equally-spaced arrays are ... case. The 3-dB widths are in the three cases: Δφ 3dB = 22. 85 o , 22. 85 o , 22. 09 o . The graphs also show the 3-dB gain circles intersecting the gains at the 3-dB angles.  20....

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... particular forms of Eq. (21.3.11) in the delta-gap and plane-wave cases. In the delta-gap case, we have E in (z)= V 0 δ(z) and the integral on the right-hand side can be done trivially, giving:  h −h F(z ... impedance matrices Z and ¯ Z for N=2M+1=201. M, and the use of the approximate kernel causing oscillations at the end-points of the antenna (and at the center for delta-gap inpu...

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... plane waves propagating in dielectrics, conductors, and birefringent me- dia, (b) guided waves propagating in hollow waveguides, transmission lines, and optical fibers, and (c) propagating waves ... jωD is the total current in the right-hand side of Amp ` ere’s law and accounts for both conducting and dielectric losses. The time-averaged version of Poynt- ing’s theorem is discu...

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... other. Examples of such waves are the evanescent waves in total internal reflection, various guided-wave problems, such as surface waves, leaky waves, and traveling-wave antennas. The most famous ... forward-moving) E (z)= A( ˆ x +j ˆ y)e −jkz (left-polarized, forward-moving) E (z)= A( ˆ x −j ˆ y )e jkz (left-polarized, backward-moving) E (z)= A( ˆ x +j ˆ y )e jkz (right-polarized, b...

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... (180 km/hr) veloc- ity resolution at a 3-GHz carrier frequency, would require B = 5 MHz and T = 1 msec, resulting in the large time-bandwidth product of BT = 5000. Such large time-bandwidth products ... quadrature weights and points h = - wp^2 * tf * J1over(wp*sqrt(x.^2 - tf^2)) .* exp(j*w0*(t(i)-x)); Ez(i) = exp(j*w0*(t(i)-tf)) + w’*h; % exact output Es(i) = exp(j*w0*t(i)-j*k0*tf...

Ngày tải lên: 13/08/2014, 02:20