The reflection coefficient, VSWR, reflection/return loss conversion

```  REFL_COEF (VOL) .. reflection coefficient (in voltage))
REFL_COEF (PWR) .. reflection coefficient (in power))
VSWR (VOL) .. voltage standing wave ratio
VSWR (dB) .. voltage standing wave ratiomin (in dB)
REFL_LOSS (dB) .. reflection loss
RETN_LOSS (dB) .. return loss
```

Select the type of parameter and input it's value, then click the "compute" button.

Unmatched load connected with transmission line causes reflected waves and following phenomenon.
```  1) transmission loss by reflection
2) frequency dependency of transmission characteristics
3) standing wave caused by interference between incident and reflected
waves
```
Generally following parameters are used to evaluate the amount of reflection. We must pay attention that all the parameters other than "reflection coeeficient" have no information about direction of reflection.

## reflection coefficient

This is the ratio of reflected wave to incident wave at point of reflection. This value varies from -1 (for short load) to +1 (for open load), and becomes 0 for matched impedance load.

## reflection coefficient in power

This is a squere of the eflection coefficient which means the ratio of the reflected power to the incident power.

## Voltage Standing Wave Ratio (VSWR)

This is the ratio of maxmum voltage to minimum voltage in standing wave pattern. It varies from 1 to (plus) infinit.

## reflection loss

This is a ratio of reflected power to incident power in dB.

## return loss

This is the dB value of absolute reflection coefficient. It is rather curious concept for transmission engneering. This loss value becomes 0 for 100% reflection and becomes infinite for ideal connection.

The reflection coefficient can be calculated from the "normalized value" of the load impedance.

```  r = (Zn - 1)/(Zn + 1)
Zn = Z/Z0

where   r = reflection coefficient
```  reflection coefficient in power = r^2