University of Cincinnati
ECE&CS Department
EE-611
Microwave Communications

Prepared by: Prof.Altan M. Ferendeci

Impedance Measurement Using VSWR Meter

Shift in Mimimum

These are based on the condition that:

• The short is connected first and the location of the voltage minima is recorded.
• Then the short is replaced by a load and the new voltage minimum is recorded minimum is recorded.
• From the shift in the minimum, the load reflection coeffient angle q_L is calculated
• From the VSWR reading, the magnitude of the reflection coefficent r_L is calculated.

The shift is either toward the generator or toward the load. These depend on:

1. Capacitive Load.
2. Inductive Load.
3. Purely Resistive load with R_L< Z_o.
4. Purely resistive load with R_L>Z_o.

   Copyright: A.M.Ferendeci, ECECS Dept.University of Cincinnati

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