Oliver Heaviside
1850 – 1925
Self-taught telegraph engineer who reformulated Maxwell and gave us operational calculus.
A self-taught telegraph operator who never held a university post, Heaviside reformulated Maxwell's twenty equations into the four vector equations physics still teaches. He invented the operational calculus that makes circuit and filter analysis tractable, coined "impedance," "inductance," and "reactance," and predicted the ionosphere.
Cantankerous and impoverished, he was dismissed by the establishment for decades before vindication. Half the electrical vocabulary on this site is his — and the transmission-line math behind the RF tools is his own.
Portrait: a stylized blueprint-line rendering, not a photograph.
Contributions in the toolbox
- 1880
Coaxial cable patented.
→ Coax Loss & Power Out - 1880
Coaxial line patented.
→ Coax Impedance from Dimensions - 1885
Operational circuit analysis normalizes the conductance view.
→ Parallel Resistors - 1885
Operational calculus makes filter math tractable.
→ RC Low-Pass Filter - 1885
Transmission-line theory — reflections quantified.
→ VSWR / Return Loss / Γ - 1885
General conductor case; the effect named and tamed.
→ Skin Depth - 1886
Names and formalizes inductance; reactive behavior theorized.
→ Reactance (XL / XC) - 1886
Coins 'impedance' for AC opposition.
→ Series RLC Impedance - 1887
Transmission-line theory explains velocity factor in cables.
→ Frequency ⇄ Wavelength