Practical_Antenna_Handbook_0071639586
I n d e x 755 maximum effective length (MEL), 334–335 maximum useable frequency (MUF), 53, 54–55, 61–64 MUF control points, 61, 64 Maxwell, James Clerk, 3, 9, 90–91 displacement current, 91–92 prediction of electromagnetic waves, 9, 90–91, 93 Maxwell’s equations, 9, 13, 88, 91, 92–93 medium (media), 12–13 megahertz (MHz), 11–12 Mercator projection, 65 meteor scatter propagation, 76 micromatch SWR bridge, 606–607 microwave antennas, 471–489 aperture, 478 arrays, 485–487 branch feed, 485–486 corporate feed, 485–486 flatplate array, 488–489 phase shifters, 485–487 slot array, 487–488 solid-Âstate, 486–487 back lobes, 477 beamwidth 476–477 Cassegrain feed geometry, 483–484 cavity antenna, 480 corner reflector, 480–481 dipole elements, 473–474 directivity, 474–477 directivity gain (G d ), 477–478 directrix (of a parabola), 481–482 dish antennas (see parabolic antennas) effective radiated power (ERP), 477 efficiency, 473, 477 feed illumination, 482 gain, 477–478, 483 gain vs. aperture, 478 horn radiators, 479 impedance, 471, 473 interference, 477 isotropic radiator, 471–472 monopulse feed system, 484–485 near field vs. far field, 472 phase shifter, 485–487 radiation loss, 473 radiation patterns, 475–476 radiation resistance, 473 reflector, 480–481 splash plate, 483 microwave waveguides, 447–470 analyzed as Âquarter-Âwavelength shorted stub, 450–451 attenuation, 377 boundary conditions, 452 characteristic impedance, 461–463 coupling methods, 468–470 aperture (slot), 470 capacitive (probe), 468–469 inductive (loop), 470 choke joints, 466–467 coordinate system, 453–454 cutoff frequency (f C ), 458–461 dominant mode, 453–454 dummy loads, 463–466 effective aperture (A e ), 478 electric fields, 449, 452–453, 461 end plate, 463, 466 feedpoint impedance and matching, 473 free-Âspace velocity (c), 454–458 frequency spectrum, 447 graphite-Âsand, 463–464 group velocity (V g ), 455–458 joints and bends, 466–468 light pipe analogy, 448 losses, 447–449 magnetic fields, 452–453, 461 materials, 449 permanent joints, 466 phase velocity (V p ), 455–458 power gain (G p ), 477–478 probe coupling, 468–469 propagation modes, 451–454 radiating vs. nonradiating slots, 470 rotating joints, 468 safety issues, 447 semipermanent joints, 466–467 side lobes, 476, 477 terminations, 463–466 transverse electric (TE) mode, 452, 453–454, 459–460, 462 transverse electromagnetic (TEM) mode, 452 transverse magnetic (TM) mode, 453–454, 461, 462 velocities, 454–458 wavelength, 454–458 millimeter waves, 12 MiniNEC modeling software, 546
756 I n d e x mismatch (VSWR) losses, transmission lines, 135–138 mobile antennas, 375–383, 369–370, 372 bandwidth, 381–382 capacitive Âtop-Âhat, 379, 382 coil-Âloaded whips, 380–382 collinear, 376 efficiency, 376–379 feedpoint impedance and matching, 377, 380 height limitations, 376, 378–379 helical whips, 380–381 HF/MF, 376–383 loaded (monopole) whips, 379–382 losses, 377–378 multiband resonator assembly, 381 top-Âloaded whip, 379 tuning, 380, 382–383 vehicular considerations, 376, 378 VHF/UHF, 375–376 VSWR minimum, 382–383 windowsill-Âmounted, 369, 371 modeling software, 545–557 basis, 545–546 convergence, 556 coordinate systems, 546–547 EZNEC+ example, 549–554 graphical user interface (GUI), 546, 549–554 grounds, 550, 552, 555, 556 method of moments, 545, 554 modeling and simulation benefits, 545 model space, 546, 548 pattern plots, 550, 553 propagation modeling, 76–78, 556–557 standing wave ratio (SWR) plots, 553–554 stepped diameter (taper) algorithms, 292–293, 554–555 terrain-Âmodeling, 78–79, 556–557 transmission lines, 555 wires, 546–548 segments, 546–547, 555 monomatch SWR bridge, 607 monopulse feeds (parabolic “dish” antennas), 484, 485 Moore, Clarence, 315 Morris, Steve, K7LXC, 671, 674 Morse code, 3, 4 Moxon, L. A., G3XN, 307 Moxon beam, 306–308 multiband and Âtunable-Âwire antennas, 217–227 antenna tuning unit (ATU), 221–222, 225 bandswitching jumpers, 220 end-Âfed Zepp antenna, 222–224 feedpoint, 222 G5RV multiband dipole, 224 harmonic operation, 222–223 log-Âperiodic, 220–221 longwire, 225 multiple-Âband dipole, 219–220 off-Âcenter-Âfed dipole, 225–226 trap dipole, 217–218 tuned feeder antennas, 221–225 Windom, 226–228 multiband fan dipole, 204 multifilar winding, 542 multihop propagation, 60–64 multipath propagation, 32 Myers, W. L., K1GQ, 309 N NASA, 20 National Bureau of Standards (See National Institute for Standards and Technology) National Institute for Standards and Technology (NIST), 50, 58 natural logarithms (ln), 709, 710 Naval Research Laboratory, 4 near field vs. far field, 472 near-Âvertical incidence skywave (NVIS), 165, 216 NEC-2, 546, 556 NEC-4, 546, 556 license, 557, 740 NECWin Plus, 546, 556 nepers, 120, 710 nitrogen-Âcooled receiver, 492 nitrogen-Âfilled cable, 112 nodes (See current; voltage) noise: antenna noise temperature, 491–495 atmospheric noise (QRN), 331, 389 canceling devices, 366, 423 galactic noise, 49 Johnson (thermal) noise, 491–492 man-Âmade noise (QRM), 266 noise bridge, 592–598 signal-Âto-Ânoise ratio (SNR), 491
- Page 726 and 727: Appendices
- Page 728 and 729: APPENDIX A Useful Math The material
- Page 730 and 731: A p p e n d i x A : U s e f u l M a
- Page 732 and 733: A p p e n d i x A : U s e f u l M a
- Page 734 and 735: A p p e n d i x A : U s e f u l M a
- Page 736 and 737: A p p e n d i x A : U s e f u l M a
- Page 738 and 739: A p p e n d i x A : U s e f u l M a
- Page 740 and 741: A p p e n d i x A : U s e f u l M a
- Page 742 and 743: A p p e n d i x A : U s e f u l M a
- Page 744 and 745: A p p e n d i x A : U s e f u l M a
- Page 746 and 747: A p p e n d i x A : U s e f u l M a
- Page 748 and 749: Appendix B Suppliers and Other Reso
- Page 750 and 751: A p p e n d i x B : S u p p l i e r
- Page 752 and 753: A p p e n d i x B : S u p p l i e r
- Page 754 and 755: A p p e n d i x B : S u p p l i e r
- Page 756 and 757: A p p e n d i x B : S u p p l i e r
- Page 758 and 759: A p p e n d i x B : S u p p l i e r
- Page 760 and 761: B.1.6 Rotators and Controllers Alfa
- Page 762 and 763: A p p e n d i x B : S u p p l i e r
- Page 764 and 765: A p p e n d i x B : S u p p l i e r
- Page 766 and 767: Index Note: Boldface numbers denote
- Page 768 and 769: I n d e x 747 Binns, Jack, first ma
- Page 770 and 771: I n d e x 749 dipole (Cont.): slopi
- Page 772 and 773: I n d e x 751 grounding and ground
- Page 774 and 775: I n d e x 753 ionospheric propagati
- Page 778 and 779: I n d e x 757 noise (Cont.): sky no
- Page 780 and 781: I n d e x 759 reactance: cancellati
- Page 782 and 783: I n d e x 761 standing waves: on an
- Page 784 and 785: I n d e x 763 transmission lines, 1
- Page 786 and 787: I n d e x 765 vertically polarized
- Page 788: I n d e x 767 Yagi antennas (Cont.)
756 I n d e x<br />
mismatch (VSWR) losses, transmission lines,<br />
135–138<br />
mobile antennas, 375–383, 369–370, 372<br />
bandwidth, 381–382<br />
capacitive Âtop-Âhat, 379, 382<br />
coil-Âloaded whips, 380–382<br />
collinear, 376<br />
efficiency, 376–379<br />
feedpoint impedance and matching, 377,<br />
380<br />
height limitations, 376, 378–379<br />
helical whips, 380–381<br />
HF/MF, 376–383<br />
loaded (monopole) whips, 379–382<br />
losses, 377–378<br />
multiband resonator assembly, 381<br />
top-Âloaded whip, 379<br />
tuning, 380, 382–383<br />
vehicular considerations, 376, 378<br />
VHF/UHF, 375–376<br />
VSWR minimum, 382–383<br />
windowsill-Âmounted, 369, 371<br />
modeling software, 545–557<br />
basis, 545–546<br />
convergence, 556<br />
coordinate systems, 546–547<br />
EZNEC+ example, 549–554<br />
graphical user interface (GUI), 546,<br />
549–554<br />
grounds, 550, 552, 555, 556<br />
method of moments, 545, 554<br />
modeling and simulation benefits, 545<br />
model space, 546, 548<br />
pattern plots, 550, 553<br />
propagation modeling, 76–78, 556–557<br />
standing wave ratio (SWR) plots,<br />
553–554<br />
stepped diameter (taper) algorithms,<br />
292–293, 554–555<br />
terrain-Âmodeling, 78–79, 556–557<br />
transmission lines, 555<br />
wires, 546–548<br />
segments, 546–547, 555<br />
monomatch SWR bridge, 607<br />
monopulse feeds (parabolic “dish” antennas),<br />
484, 485<br />
Moore, Clarence, 315<br />
Morris, Steve, K7LXC, 671, 674<br />
Morse code, 3, 4<br />
Moxon, L. A., G3XN, 307<br />
Moxon beam, 306–308<br />
multiband and Âtunable-Âwire antennas, 217–227<br />
antenna tuning unit (ATU), 221–222, 225<br />
bandswitching jumpers, 220<br />
end-Âfed Zepp antenna, 222–224<br />
feedpoint, 222<br />
G5RV multiband dipole, 224<br />
harmonic operation, 222–223<br />
log-Âperiodic, 220–221<br />
longwire, 225<br />
multiple-Âband dipole, 219–220<br />
off-Âcenter-Âfed dipole, 225–226<br />
trap dipole, 217–218<br />
tuned feeder antennas, 221–225<br />
Windom, 226–228<br />
multiband fan dipole, 204<br />
multifilar winding, 542<br />
multihop propagation, 60–64<br />
multipath propagation, 32<br />
Myers, W. L., K1GQ, 309<br />
N<br />
NASA, 20<br />
National Bureau of Standards (See National<br />
Institute for Standards and Technology)<br />
National Institute for Standards and<br />
Technology (NIST), 50, 58<br />
natural logarithms (ln), 709, 710<br />
Naval Research Laboratory, 4<br />
near field vs. far field, 472<br />
near-Âvertical incidence skywave (NVIS), 165,<br />
216<br />
NEC-2, 546, 556<br />
NEC-4, 546, 556<br />
license, 557, 740<br />
NECWin Plus, 546, 556<br />
nepers, 120, 710<br />
nitrogen-Âcooled receiver, 492<br />
nitrogen-Âfilled cable, 112<br />
nodes (See current; voltage)<br />
noise:<br />
antenna noise temperature, 491–495<br />
atmospheric noise (QRN), 331, 389<br />
canceling devices, 366, 423<br />
galactic noise, 49<br />
Johnson (thermal) noise, 491–492<br />
man-Âmade noise (QRM), 266<br />
noise bridge, 592–598<br />
signal-Âto-Ânoise ratio (SNR), 491
Change language