Electromagnetic Waves and Antennas combined - Chapter 19 doc

... ψ-space) (19. 10.2) Combining Eqs. (19. 10.1) and (19. 10.2) and replacing kd by 2πd/λ, we get: Δφ 3dB = 0.886 sin φ 0 λ Nd b, (3-dB width in angle-space) (19. 10.3) The 3-dB angles will be approximately ... antennas being synchronized with atomic frequency standards, and then the recorded signals are digitally cross-correlated and processed off-line. The achievable resolution is ab...

Ngày tải lên: 13/08/2014, 02:20

... 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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... 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 ... gains of two 21-element three-beam arrays with half- wavelength spacing, and steered towards the three angles of 45 o ,90 o , and 120 o . The broadside array was designed as a Tay...

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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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... field. If antenna-2 is open-circuited and the z-component of the electric field generated by antenna-1 and incident on antenna-2 is E 21 (z), then according to Eq. (21.5.6), the induced open-circuit voltage ... dipoles by the generators and by their mu- tual interaction, and let h 1 ,h 2 be the half-lengths of the antennas, and a 1 ,a 2 , their radii. Then, assuming the thin-wire mod...

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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