Coef Transmissão
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The transmission coefficient calculator determines the proportion of wave intensity that transfers between two media with different impedances. The formula T = 4Z₁Z₂/(Z₁+Z₂)² uses the impedances Z₁ and Z₂ of adjacent materials. This is applied in acoustics, electromagnetism, and optics to predict transmission efficiency.
Impedance (Z) represents a medium's resistance to wave propagation. When Z₁ equals Z₂, the coefficient reaches maximum (1), indicating full transmission. Unequal values generate losses, with partial reflection. The calculator helps optimize systems like optical fibers or acoustic barriers.
Use this tool in engineering projects where reflection minimization is critical. For instance, antenna design or audio systems to prevent distortions. Note: Impedance values must share the same unit (ohms, kg/s³, etc.) for accurate results.
Frequently asked questions
How does transmission coefficient relate to reflection coefficient?
The sum of transmission (T) and reflection coefficients is 1. If T = 0.8, reflection (r) = 0.2, meaning 80% transmitted and 20% reflected.
What units should be used for Z₁ and Z₂?
Use the same unit for both impedances, such as ohms for electromagnetism or kg/s³ for mechanical waves.
What do values close to 1 indicate?
Values near 1 mean efficient transmission, useful in systems like coaxial cables to minimize signal loss.
What happens if Z₁ = Z₂?
Equal impedances achieve the maximum theoretical transmission coefficient (T = 1), indicating no reflection.