📡 EM Wave

Frequency f—
Wavelength λ—
Wave speed c3.00×10⁸ m/s
Impedance Z₀377 Ω
|S| Poynting—
Maxwell plane wave
E = E₀ sin(kx−ωt) ŷ
B = B₀ sin(kx−ωt) ẑ
B₀ = E₀/c, Z₀ = μ₀c = 377 Ω
S = E×B/μ₀ (x̂ direction)