Presentation on theme: "EMLAB 1 Transmission line. EMLAB 2 An apparatus to convey energy or signal from one place to another place. Transmitter to an antenna connections between."— Presentation transcript:
EMLAB 2 An apparatus to convey energy or signal from one place to another place. Transmitter to an antenna connections between computers in a network hydroelectric generating plant and a substation several miles away interconnect between components of a stereo system CATV service provider and your TV set Connections between devices on a circuit board Transmission line
EMLAB 8 Types of transmission lines Microstrip line Coaxial cable Two-wire transmission line
EMLAB 9 Distribution of electric field strengths of typical TEM lines E/H distributions vary as the structures of transmission lines change. For electromagnetic compatibility, E/H should be confined to small area. Microstrip Two-wire Parallel plate
EMLAB 15 Transmission line 의 특징 H E Direction of propagation H 1.For a magnetic field and an electric field propagating in the same direction, the ratio of E and H (E + /H + ) is kept constant. 2.For a voltage and a current current propagating in the same direction, V + /I + ratio is equal to Z 0. 3.When the ratio is disturbed, reflected waves are generated.
EMLAB 17 +V-+V- +V-+V- +V-+V- +V-+V- +V-+V- Z s = 20 Z 0 = 50 Z L = 1k 0.5m Influence of line length on load voltage Impedance mismatched VinVout R R2 R=1k Ohm MLIN R R1 R=20 Ohm VtPulse SRC1 t Z 0 = 50
EMLAB 25 Transmission line terminated with short, open Zs = Zo V refl V inc For reflection, a transmission line terminated in a short or open reflects all power back to source In phase (0 ) for open o Out of phase (180 ) for short V refl o
EMLAB 26 Transmission Line Terminated with 25 Ω Zs = Zo Z L = 25 W V refl V inc Standing wave pattern does not go to zero as with short or open