Approaches for performing in line wafer testing are provided. An approach includes a method that includes generating a radio frequency (RF) test signal, and applying the RF test signal to a device under test (DUT) in a wafer using a buckling beam probe set with a predefined pitch. The method also includes detecting an output RF signal from the DUT in response to the applying the RF test signal to the DUT, and sensing at least one frequency component of the detected output RF signal.