The relationship between Γ L and Z 0 is as follows: or where Γ L = Reflection coefficient at the load (dimensionless number, comprised between +1 and -1) Z L = Impedance of the load ( Ω ) Z 0 = Characteristic impedance of the line ( Ω ). Instead, part of this energy is reflected back toward the source by a reflection coefficient Γ L. DISCUSSION Relationship Between the Reflection Coefficient at the Load and the Load Impedance As you have already learned, when the impedance of the load does not perfectly match the characteristic impedance of the waveguide, Z 0, not all the energy incident at the load is absorbed by the load. You will be able to measure load impedances by using a slotted line and the Smith Chart. 11-1 Exercise 11 Impedance Measurements EXERCISE OBJECTIVES When you have completed this exercise, you will know how a Smith Chart is constructed, and how to use it to determine load impedances.