From first principles to advanced beamforming — our library of guides, tutorials, and deep-dives is free for engineers, students, and enthusiasts worldwide.
Structured topic guides — each covers a complete subject area with articles, equations, and worked examples.
From why a wire becomes a transmission line to a measured RF board — RLGC model, Z₀, propagation, reflections and VSWR, losses, microstrip, CPW, stripline, stubs, discontinuities and resonators.
A practical guide to the most common antenna types — how each works, where it's used, and how to choose the right one for your application.
From electric and magnetic fields to the four equations, electromagnetic waves and boundary conditions — and how they shape lines, waveguides and antennas.
From impedance, reflection coefficient and VSWR to reading the Smith chart and designing L-network and stub matches for real antennas.
How antennas radiate, and every parameter that describes them — patterns, directivity and gain, impedance, S11, efficiency, bandwidth, polarization, aperture and the Friis link.
Part 2: what a transmission line is, the definition of characteristic impedance Z₀ = √(L/C), voltage and current on a line, Z₀ of coaxial cables and microstrip lines, why 50 Ω and 75 Ω systems are used, and the factors that change Z₀.
Read guide →Part 3: load impedance and reflections, the reflection coefficient Γ = (Z_L − Z₀)/(Z_L + Z₀), its magnitude and phase, short, open and matched loads, return loss, S11 and reflected power, with Smith Chart Calculator examples.
Read guide →Part 4: how standing waves form on a mismatched line, voltage maxima and minima, the definition of VSWR, conversions between VSWR, Γ, return loss and mismatch loss, the VSWR circle on the Smith chart, and why VSWR matters.
Read guide →Part 5: the input impedance of a transmission line, impedance transformation as rotation on the Smith chart, λ/8, λ/4 and λ/2 lines, the quarter-wave transformer, short- and open-circuited stubs, and physical line lengths.
Read guide →Part 6: the purpose and history of the Smith chart, how it is constructed from the reflection-coefficient plane, its regions and special points, the impedance and admittance charts, and how to read the combined Z/Y chart.
Read guide →Part 7: normalised impedance and admittance (z = Z/Z₀, y = Y·Z₀), denormalising chart readings, changing the reference impedance from 50 Ω to 75 Ω, and converting normalised values into inductor and capacitor values.
Read guide →Reach out directly — we're a small team of RF engineers and we actually reply.