The basic function of the Test Fixture is to allow for resource routing from the test system to the Device Under Test (DUT). It also provides application specific resources to be applied to the DUT. To be functional, a fixture needs to do the following:

• Provide the RF, AC, and DC interfaces between the tester and itself.
• Provide the RF, AC, and DC interfaces between itself and the DUT interface board.
  This may also include the DUT Interface Board (DIB) and socket as an integral part of the fixture hardware.
• Provide any specialty signal switching or processing required between the test head and the DUT

The fixture can be thought of as consisting of several physical and software layers.

The physical layers of a fixture include:

• Bottom Plate Assembly - Tester to Fixture Interface
• Interior Routing and Signal processing Layer (Modules, Wiring, and Cables)
• Top Plate Assembly - Fixture to DIB Interface
• DUT interface board (DIB) and socket

• Software Fixture - Defines fixture resource controls and stores calibration data
• Software DUT Interface - Stores DIB calibration data
• Software DUT - DUT Digital Control Registers and DUT Offsets

Device Interface	DUT	Fixture