Formulas
Attenuation
Voltage: Av = 20log(Vout/Vin)
Power: Ap = 10log(Pout/Pin)
Electrical Length
L(nsec) = d(ft) x (√K) / Co
Where K = dielectric constant and Co = speed of light » 1 ft/nsec
Impedance
Transmission Line: ZO = √(L/C)
Where C = capacitance, L = inductance
Propagation Delay
PD (nsec/ft) = (√K)/Co
Where K = dielectric constant and Co = speed of light » 1 ft/nsec
Reactance
Capacitor: XC = 1/(2πfC)
Inductor: XL = 2πfL
Where f = frequency, C = capacitance, L = inductance
Velocity of Propagation
VP (%) = 1/(√K) x 100
Where K = dielectric constant
Wavelength
λ = Co /f (in air)
λ = Co /(f x √K) (in any dielectric)
Where Co = speed of light and f = frequency
For example: λAIR = (1.18 x 1010 in/sec)/(5 x 109 Hz) = 2.4 inches @ 5 GHz
λFR-4 = (1.18 x 1010 in/sec)/((5 x 109 Hz)(√4.5)) = 1.1 inches @ 5 GHz
