16.360 Lecture 4
Download
1 / 10

16.360 Lecture 4 - PowerPoint PPT Presentation


  • 110 Views
  • Uploaded on

16.360 Lecture 4. Transmission lines. Transmission line parameters, equations Wave propagations Lossless line, standing wave and reflection coefficient Input impedence Special cases of lossless line Power flow Smith chart Impedence matching Transients on transmission lines.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' 16.360 Lecture 4' - guinevere-burch


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

16.360 Lecture 4

  • Transmission lines

  • Transmission line parameters, equations

  • Wave propagations

  • Lossless line, standing wave and reflection coefficient

  • Input impedence

  • Special cases of lossless line

  • Power flow

  • Smith chart

  • Impedence matching

  • Transients on transmission lines


16.360 Lecture 4

  • Transmission line parameters, equations

B

A

VBB’(t) = VAA’(t)

VBB’(t)

Vg(t)

VAA’(t)

L

A’

B’

VAA’(t) = Vg(t) = V0cos(t),

Low frequency circuits:

VBB’(t) = VAA’(t)

Approximate result

VBB’(t) = VAA’(t-td) = VAA’(t-L/c)

= V0cos((t-L/c)),


B

A

VBB’(t)

Vg(t)

VAA’(t)

L

A’

B’

16.360 Lecture 4

  • Transmission line parameters, equations

Recall: =c, and  = 2

VBB’(t) = VAA’(t-td) = VAA’(t-L/c)

= V0cos((t-L/c))

= V0cos(t- 2L/),

If >>L, VBB’(t)  V0cos(t) = VAA’(t),

If <= L, VBB’(t) VAA’(t), the circuit theory has to be replaced.


B

A

VBB’(t)

Vg(t)

VAA’(t)

L

A’

B’

16.360 Lecture 4

  • Transmission line parameters, equations

e. g:  = 1GHz, L = 1cm

Time delay

t = L/c = 1cm /3x1010 cm/s = 30 ps

Phase shift

 = 2ft = 0.06 

VBB’(t) = VAA’(t)

 = 10GHz, L = 1cm

Time delay

t = L/c = 1cm /3x1010 cm/s = 30 ps

Phase shift

 = 2ft = 0.6 

VBB’(t) VAA’(t)


B

A

VBB’(t)

Vg(t)

VAA’(t)

L

A’

B’

16.360 Lecture 4

  • Transmission line parameters

  • time delay

VBB’(t) = VAA’(t-td) = VAA’(t-L/vp),

  • Reflection: the voltage has to be treat as wave, some bounce back

  • power loss: due to reflection and some other loss mechanism,

  • Dispersion: in material, Vp could be different for different wavelength


B

E

16.360 Lecture 4

  • Types of transmission lines

  • Transverse electromagnetic (TEM) transmission lines

B

E

a) Coaxial line

b) Two-wire line

c) Parallel-plate line

d) Strip line

e) Microstrip line


16.360 Lecture 4

  • Types of transmission lines

  • Higher-order transmission lines

a) Optical fiber

b) Rectangular waveguide

c) Coplanar waveguide


16.360 Lecture 4

  • Lumped-element Model

  • Represent transmission lines as parallel-wire configuration

A

B

Vg(t)

VBB’(t)

VAA’(t)

B’

A’

z

z

z

R’z

L’z

L’z

R’z

L’z

R’z

Vg(t)

G’z

C’z

C’z

C’z

G’z

G’z



Definitions of tl dimensions
Definitions of TL dimensions

TEM (Transverse Electromagnetic): Electric and magnetic fields are orthogonal to one another, and both are orthogonal to direction of propagation


ad