A test station and method of testing a design under test are disclosed. One method includes applying a first test frequency signal to a reference path to determine a first known attenuation level, and applying the first test frequency signal to a design under test to determine a first tested attenuation level of the design under test at the first test frequency. The method also includes applying a second test frequency signal to the reference path to determine a second known attenuation level, and applying the second test frequency signal to the design under test to determine a second tested attenuation level of the design under test at the second test frequency. The method includes determining whether the design under test is faulty based on the first tested attenuation level and the second tested attenuation level.