Meaning
Specialized interface assembly designed to connect a device under test to measurement instruments while maintaining signal integrity at gigahertz frequencies. Every high frequency test fixture must minimize signal loss and reflection through the use of impedance-matched components and short signal paths. The assembly provides a platform for making repeatable electrical contacts without damaging the device under test.
Signal Integrity
Engineering of the signal path requires the use of dielectric materials with low loss characteristics. Within the high frequency test fixture, coaxial cables and shielding prevent external interference from affecting the sensitive radio measurements. These features allow for accurate characterization of transmitter power and receiver sensitivity without the risk of external noise floor contamination.
Advanced modeling of the electrical path ensures that the fixture does not introduce parasitic inductance into the measurement circuit.
Mechanical Precision
Alignment of the device pins with the contact probes requires tight tolerances in the fixture housing. The high frequency test fixture utilizes precision guide pins to ensure that the device under test seats perfectly every time the lid closes. Even a small misalignment of a millimeter can cause a failure in the high frequency return loss measurement.
Maintenance Requirement
Cleaning of the contact surfaces is necessary to prevent the buildup of debris. Over several thousand cycles, the pogo pins inside the high frequency test fixture will wear and require replacement to maintain measurement accuracy.
