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 8: the antenna reflection coefficient derived, return loss, VSWR and mismatch loss, accepted power, reading S11 plots, how cables hide mismatch, and L-network and quarter-wave matches for real antennas.
Read guide →Part 9: radiation, mismatch and total efficiency — conductor loss from the surface current, dielectric loss and loss tangent, efficiency from Q, small antennas and loading coils, ground loss, and Wheeler-cap measurement.
Read guide →Part 10: impedance, pattern, gain and polarization bandwidth, fractional and ratio bandwidth, the −10 dB criterion, bandwidth from Q derived, the Chu limit, the Bode–Fano limit and bandwidth-enhancement techniques.
Read guide →Part 11: the polarization ellipse derived, linear, circular and elliptical polarization, RHCP and LHCP, axial ratio, polarization loss factor, co- and cross-polarization, reflection and Faraday rotation.
Read guide →Part 12: effective aperture A_e = Gλ²/4π derived from reciprocity, physical aperture and aperture efficiency, received power, effective length and effective height, received voltage and the EMC antenna factor.
Read guide →Part 14: antenna types with design equations — dipoles, monopoles, loops, horns, slots, microstrip patches, reflectors, helices, spirals, Yagi-Uda, log-periodic, dielectric resonator, travelling-wave and UWB antennas.
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