RF test fixtures are used to test integrated circuit boards in devices like televisions. They allow for testing of signals up to 6GHz by providing radio frequency compatible shielding and protection for printed circuit boards. RF test fixtures have key features - they shield against outside interference, allow for non-reflective measurement of high frequency signals, provide a quick exchange system that allows changes without tools, and can adjust in post conditions. RF test probes are used to transmit signals with minimal loss or reflection from the circuit boards to the test system through an EM-compatible RF chamber.