Everything that travels wirelessly first travels on a wire — through a coaxial cable, a PCB microstrip trace, or a stripline buried in a multilayer board. Understanding how signals propagate on these structures, how reflections arise, and how to design for minimal loss is the foundation of all RF engineering.
Work through these articles in order for a complete understanding of transmission line theory, or jump to whichever topic you need.
Why a wire is not just a wire at RF frequencies — when lumped-circuit models break down, what a transmission line really is, and why understanding wave propagation on guided structures is essential for every RF engineer.
Read article → ● IntermediateA rigorous derivation from first principles. The distributed RLGC circuit model, Kirchhoff's voltage and current laws, the wave equation, propagation constant γ = α + jβ, characteristic impedance Z₀, and travelling voltage and current waves.
Read article → ● IntermediateApplying boundary conditions to a lossless line with an arbitrary load — voltage reflection coefficient, input reflection coefficient, input impedance, quarter-wave transformer, stubs, standing wave patterns, and VSWR.
Read article →Browser-based calculators to apply transmission line theory directly.
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