0195136047.pdf

674 COMMUNICATION SYSTEMS Witha=0.445 mm,b=1.473 mm,εr= 2 .26 for polyethylene dielectric, tanδ= 2 × 10 −^4 , andρ= 1. 63 × 10 − ...

15.1 WAVES, TRANSMISSION LINES, WAVEGUIDES, AND ANTENNA FUNDAMENTALS 675 (a) For a rectangular air-filled waveguide witha=4.8 cm ...

676 COMMUNICATION SYSTEMS Pin Pout G 1 Preamplifier L 1 α 1 1 G 2 G 3 Repeater Receiving amplifier L 2 α 2 2 Figure 15.1.4Transm ...

15.1 WAVES, TRANSMISSION LINES, WAVEGUIDES, AND ANTENNA FUNDAMENTALS 677 system that involves antennas (with no conductors in th ...

678 COMMUNICATION SYSTEMS G= 4 πAe λ^2 (15.1.17) whereλis the wavelength being transmitted (or received), andAeis theeffective a ...

15.1 WAVES, TRANSMISSION LINES, WAVEGUIDES, AND ANTENNA FUNDAMENTALS 679 L=LtLtaLchLraLr (15.1.22) Srwould then be given by Sr= ...

680 COMMUNICATION SYSTEMS EXAMPLE 15.1.5 (a) Some antennas have a physical aperture areaAthat can be identified and is related t ...

15.1 WAVES, TRANSMISSION LINES, WAVEGUIDES, AND ANTENNA FUNDAMENTALS 681 Transmission line Transmission line Active element (reg ...

682 COMMUNICATION SYSTEMS x z y A (a) (b) Side lobes Main lobe Direction of maximum To R R θ φ x A z y Figure 15.1.8(a)Spherical ...

15.1 WAVES, TRANSMISSION LINES, WAVEGUIDES, AND ANTENNA FUNDAMENTALS 683 (a) (b) Main lobe Main lobe 0 Relative radiation intens ...

684 COMMUNICATION SYSTEMS (a) (b) (c) x y z x y z x y z E− E− E− Figure 15.1.10Polarizations of the electric field.(a)Vertical p ...

15.2 ANALOG COMMUNICATION SYSTEMS 685 Nao= kTsysBNGa(f 0 ) Lr (15.1.30) The signal-to-noise power ratio at the system output is ...

686 COMMUNICATION SYSTEMS 15 kHz. Distortion at most stations is below 1%. Besides broadcast applications, FM is also used in sa ...

15.2 ANALOG COMMUNICATION SYSTEMS 687 whereas the sinusoidal carrier waveform is given by c(t)=Accos(ωct+φc)=Accos( 2 πfct+φc) S ...

688 COMMUNICATION SYSTEMS USB LSB LSB USB Spectral impulse due to carrier Spectral impulse due to carrier Lower sideband (LSB) A ...

15.2 ANALOG COMMUNICATION SYSTEMS 689 EXAMPLE 15.2.1 Letf(t) be a sinusoid given byf(t)=Amcosωmtwith periodTm= 2 π/ωm. Apply Equ ...

690 COMMUNICATION SYSTEMS A relatively simple method to generate a DSB SC AM signal is by employing two (identical) conventional ...

15.2 ANALOG COMMUNICATION SYSTEMS 691 television broadcast system. The generation of VSB is similar to the generation of SSB, ex ...

692 COMMUNICATION SYSTEMS 1 fc << RC << 1 W (15.2.8) The simplicity of the demodulator has made conventional DSB AM ...

15.2 ANALOG COMMUNICATION SYSTEMS 693 From thenoise performancepoint of view, all the AM systems yield the same performance for ...