Free Learning Resources

RF & Antenna Education

From first principles to advanced beamforming — our library of guides, tutorials, and deep-dives is free for engineers, students, and enthusiasts worldwide.

Browse by Topic

Learning Paths

Structured topic guides — each covers a complete subject area with articles, equations, and worked examples.

Microstrip transmission line cross-section showing conductor, substrate, and ground plane

Transmission Line Theory

Wave propagation on guided structures — characteristic impedance, reflection, standing waves, and microstrip design.

Microstrip Impedance VSWR εeff Stripline

Explore topic →

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.

Patch Dipole Yagi-Uda Horn Helix Arrays

Explore topic →

Electromagnetics · 10-Part Series

Maxwell's Equations

From electric and magnetic fields to the four equations, electromagnetic waves and boundary conditions — and how they shape lines, waveguides and antennas.

Gauss's Law Faraday Ampère–Maxwell EM Waves Boundaries

Explore topic →

RF Fundamentals · 12-Part Series

Smith Chart & Impedance Matching

From impedance, reflection coefficient and VSWR to reading the Smith chart and designing L-network and stub matches for real antennas.

Impedance Γ & VSWR Smith Chart L-Networks Stubs

Explore topic →

Showing 35 articles · Page 5 of 6

6 per page

RF Fundamentals

Understanding Characteristic Impedance of Transmission Lines

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.

RF Fundamentals

Understanding Load Impedance and Reflection Coefficient

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.

RF Fundamentals

Standing Waves and Voltage Standing Wave Ratio (VSWR)

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.

RF Fundamentals

Impedance Transformation Along Transmission Lines

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.

RF Fundamentals

Introduction to the Smith Chart

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.

RF Fundamentals

Understanding Normalized Impedance on the Smith Chart

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.

Have a Technical Question?

Reach out directly — we're a small team of RF engineers and we actually reply.

Ask a Question View Products