Week 01
Distributed-Circuit View
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
When a circuit is not electrically small compared with wavelength, a lumped model cannot treat voltage and current as uniform across a node. Electrical length and phase velocity create position-dependent phase, requiring a distributed-circuit view.
Concept map
- Electrical length
- Wavelength
- Lumped and distributed models
- Phase velocity
Technical anchor
Electrical length is θ=βl=2πl/λ and phase velocity is vp=ω/β. The same physical length produces a larger phase shift as frequency rises and wavelength shortens.
How I review it
Compare the longest interconnect with guided wavelength at the frequency of interest, and represent interconnects as transmission lines once their electrical length is no longer negligible.
Connection to the full course
Unit 1 of 12. Unit numbers arrange the saved assignments and circuits by concept flow rather than attendance weeks.