# Transmission / Reflection Goal

Optimise the transmission and reflection quantities that are solved as part of the Feko model.

On the Request tab, in the Optimisation group, click the  Add goal function icon. From the drop down list, select  Transmission / Reflection Goal. The Focus is identified based on the label of a Transmission/Reflection coefficient request in CADFEKO or of a TR card in EDITFEKO.

## Focus type

Transmission
The transmission coefficient is calculated as
(1) $\tau =\frac{{\text{E}}_{t}}{\text{E}{}_{i}}$
Reflection
The reflection coefficient is calculated as
(2) $\rho =\frac{{\text{E}}_{r}}{\text{E}{}_{i}}$

## Polarisation

Choose to optimise Co-polarisation or Cross-polarisation.