Microwave engineering ch2
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This document provides an overview of transmission line theory and microwave transmission lines. It discusses the lumped element circuit model used to model transmission lines and the concept of wave propagation in transmission lines. It also covers different types of transmission lines including microstrip lines, waveguides, and coaxial cables. Key transmission line parameters are defined, such as characteristic impedance, cut-off frequency, and electromagnetic mode. Specific modes and characteristics are described for microstrip lines and rectangular waveguides.
Microwave engineering ch2
- 2. WEEK 1 • CLASS 1:The lumped-element circuit model for a transmission line,Wave propagation in a transmission line • CLASS 2: Field analysis of transmission lines, Classification of transmission lines,
- 3. WEEK 2 • CLASS 3:The terminated lossless transmission line, VSWR,The Smith Chart. • CLASS 4:The quarter wave transformer,Transients on transmission lines, Generator and load mismatches
- 5. A transmission line is a system that is capable of “guiding” the energy transfer between a generator and a load Derivation of the Telegrapher’s Eqtn Equation (6) - Board } Gives rise to voltage and current that is a function of time and distance Lumped element circuit model of a TL
- 6. WAVE PROPAGATION IN ATRANSMISSION LINE Wave Propagation in TL Equation: Equation (7) - Board
- 7. TYPES OFTRANSMISSION LINES Microstrip Line Waveguide Coax Cable Field Lines
- 8. SEVERAL “CONCERNS”WITHTL CHARACTERISTIC IMPEDANCE CUT-OFF FREQUENCY ELECTROMAGNETIC MODE Ratio of the voltage to current when there is no reflection from the load (infinitely long line) Frequency at which the desirable field patterns are excited in any type ofTL. The EM field pattern measured at a plane perpendicular (i.e., transverse) to the propagation direction of the wave. Note that aTL can have more than one mode
- 9. TYPE OF EM MODE Transverse Electric-Magnetic (TEM) Transverse Electric (TE) Transverse Magnetic (TM) Neither electric nor magnetic field in the direction of propagation No electric field in the direction of propagation. These are sometimes called H modes because there is only a magnetic field along the direction of propagation No magnetic field in the direction of propagation. These are sometimes called E modes because there is only an electric field along the direction of propagation
- 10. MICROSTRIP LINE Dielectric CHARACTERISTIC IMPEDANCE CUT-OFF FREQUENCY ELECTROMAGNETIC MODE SIDEVIEW Fundamental Mode: Quasi TEM @ ‘d’ Anything above the fc, a different EM mode is excited (higher- order mode)
- 11. RECTANGULAR WAVEGUIDE Dielectric CHARACTERISTIC IMPEDANCE CUT-OFF FREQUENCY ELECTROMAGNETIC MODE Fundamental Mode: TE(10) @ ‘d’ Anything above the fc, a different EM mode is excited (higher- order mode) TE TM