The standard Smith chart is usually designed to accommodate reflection coefficient values of 1.0. However, in certain cases this may not be the case. For instance in problems of negative resistance manipulations using the Smith Chart. When this is the case an extended Smith Chart can be drawn for any value of the reflection coefficient. This chart can then be used in the same way as the standard chart. Of course if the values of the negative resistance become too large then these can lead to impractical circuits.