Week 02
Transmission-Line Equations
I revisit transmission lines through Wilkinson and branch-line networks using my assignments, Cadence circuits, and S-parameter figures.
What I connect in this unit
Transmission-line equations begin with per-unit-length R, L, G, and C causing voltage and current to vary with position. Characteristic impedance and propagation constant set forward/reflected-wave relations and attenuation or phase; a lossless line is the R=G=0 case.
Concept map
- Characteristic impedance
- Propagation constant
- Forward and reflected waves
- Lossless lines
Technical anchor
Use Z0=sqrt((R+jωL)/(G+jωC)) and γ=sqrt((R+jωL)(G+jωC)) with V(z)=V+e^-γz+V-e^γz. For a lossless line these reduce to Z0=sqrt(L/C) and γ=jωsqrt(LC).
How I review it
Normalize the per-unit-length units first, then check that the real and imaginary parts of Z0 and γ agree with passive-line attenuation and the chosen propagation convention.
Connection to the full course
Unit 2 of 12. Unit numbers arrange the saved assignments and circuits by concept flow rather than attendance weeks.