It is because it represents 180 degrees of a wavelength. every 180 degrees the impedance on a transmission line repeats itself
i looks circular like
It is a circular chart which is divided into at least two parts.
pie chart
Data collection
It can also be called a circular graph
Phillip Smith has written: 'Electronic applications of the Smith Chart'
A circular pie chart is a type of graph that does not have an x and y axis.
If you look at the reflection coefficient curve as a function of frequency, it follows a counter-clockwise direction about the Smith chart. You should see a loop, and at the "top" of the loop, that is the oscillation frequency.They both have in common an open-loop gain greater than one, however. So the curve will be outside the Smith chart.
Phillip Hagar Smith has written: 'Electronic applications of the Smith chart' -- subject(s): Smith charts
to calculate impedence of power supply
Charts are excellent tools used to create visual representations of data. Circular flow charts are particularly helpful when demonstrating cycles or exchanges.
The movement of income from producers of goods and services to consumers, and back to the producer is known as the circular flow. Circular flow is generally shown in a circular flow chart or model.