In this video, you will able to understand the definition as well as the concept of transmission lines along with its types relevant to various applications. Additionally, you will able to have an idea about various transmission line parameters along with its formula corresponding to each type.
2. INTRODUCTION TO TRANSMISSION LINES
One of the means of transmitting power or information is by guided
structures. Guided structures serve to guide (or direct or navigate) the
propagation of energy from the source to the load.
Typical examples of such structures are transmission lines and
waveguides.
Transmission lines are commonly used in power distribution (at low
frequencies) and in communications (at high frequencies).
A transmission line basically consists of two or more parallel
conductors used to connect a source to a load.
The source may be a hydroelectric generator, a transmitter, or an
oscillator; the load may be a factory, an antenna, or an oscilloscope,
respectively.
Transmission line problems are usually solved using EM field theory
and electric circuit theory
Our analysis of transmission lines will include the derivation of the
transmission-line equations and characteristic quantities, the use of
the Smith chart, various practical applications of transmission lines
3. TYPES OF TRANSMISSION LINES
Typical transmission lines include coaxial cable, a two-wire line, a
parallel-plate or planar line, a wire above the conducting plane, and a
microstrip line.
Coaxial cables are routinely used in electrical laboratories and in
connecting TV sets to TV antennas.
Microstrip lines are particularly important in integrated circuits where
metallic strips connecting electronic elements are deposited on
dielectric substrates.
Co-axial Line 2 Wire Line Planar Line Wire above the
Conducting Plane
Microstrip Line
4. TRANSMISSION LINE PARAMETERS
To describe a transmission line in terms of its line parameters, which
are its resistance per unit length R, inductance per unit length L,
conductance per unit length G, and capacitance per unit length C.
Each of the lines has specific formulas for finding R, L, G, and C.
1. The line parameters R, L, G, and C are not discrete or lumped but
distributed. By this we mean that the parameters are uniformly
distributed along the entire length of the line.
2. For each line, the conductors are characterized by σC, μC, C = 0 and
the homogeneous dielectric separating the conductors is
characterized by σ, µ and .
3. For each line,
LC = μ G/C = σ/