Transmission-line model, telegrapher equations, propagation constant, characteristic impedance and line power.
Distributed circuits & transmission lines from Maxwell
Build transmission-line theory as a controlled reduction of electromagnetic propagation: first local voltage/current and distributed storage/loss, then telegrapher equations, characteristic impedance, propagation constant and line power.
- EM-04 — electromagnetic waves & power
- AC-02 — frequency response
- Basic differential calculus
- Decide when an interconnect must be modeled as a transmission line.
- Derive distributed equations from an infinitesimal line element.
- Connect R′,L′,G′,C′ to fields, loss and stored energy.
- Obtain γ and Z₀ and interpret propagation, attenuation and power.
Distributed circuits & transmission lines from Maxwell
Build transmission-line theory as a controlled reduction of electromagnetic propagation: first local voltage/current and distributed storage/loss, then telegrapher equations, characteristic impedance, propagation constant and line power.
- 01→
From lumped circuits to distributed lines
Decide when propagation delay matters, define voltage and current on a two-conductor line, connect fields to per-unit-length R′, L′, G′ and C′, derive the infinitesimal line element and obtain the time-domain telegrapher equations from local KVL/KCL without treating them as memorized RF formulas.
180–230 min · Advanced · available - 02→
Solve the telegrapher equations
Move the time-domain line equations into AoN phasor form, define the series impedance and shunt admittance per unit length, decouple the system, derive γ²=Z′Y′, interpret γ=α+jβ, and obtain forward/backward voltage and current waves with the correct reverse-current sign.
180–230 min · Advanced · available - 03→
Characteristic impedance
Promote the forward-wave voltage/current ratio to the exact lossy characteristic impedance Z₀=√(Z′/Y′), tie its branch to passive γ, recover the lossless limit, connect Z₀ to geometry through a TEM coax example, derive the low-loss approximation and use the backward-current sign to audit transported power.
190–245 min · Advanced · available - 04→
Propagation constant, loss & distortion
Open γ=α+jβ into exact attenuation and phase, derive the low-loss conductor/dielectric contributions, convert nepers to decibels, distinguish phase and group delay, prove the Heaviside distortionless condition and delimit the frequency-independent RLGC model.
190–245 min · Advanced · available - 05→
Transmission-line power flow
Derive instantaneous and harmonic line power from the fixed voltage/current references, preserve the peak-phasor factor 1/2, distinguish forward/backward signed power, obtain the exact local RLGC loss balance, recover the Poynting-flux identity for a TEM line, connect power to stored energy and introduce a safe real-Z₀ normalization before later scattering theory.
200–255 min · Advanced · available
References
The course uses field theory and microwave texts together so that line quantities retain their electromagnetic meaning.
Distributed-line theory, field interpretation and rigorous transmission-line limits.
Connection between electromagnetic fields, two-conductor lines, stored energy and distributed parameters.