kicad/pcb_calculator/attenuators/tee_formula.md

Tee Attenuator

a is attenuation in dB
Z_in is desired input impedance in Ω
Z_out is desired output impedance in Ω

K = V_I/V_O = 10^a/20
L = K² = 10^a/10
A = (L+1) / (L−1)

R2 = 2·√(L · Z_in · Z_out) / (L−1)
R1 = Z_in · A − R2
R3 = Z_out · A − R2