RF Test Sockets are used to test high frequency IC's without soldering them on to a PCB. The IC is placed in a test socket which is soldered on to a PCB board which is placed within a test setup. It is easy to add and remove an IC from a test socket.

An ideal test socket should be electrically “transparent;” that is, its presence should have no effect on the test results. This characteristic can be achieved with a low self-inductance and capacitance between contacts, and the contact’s ability to maintain controlled impedance. The heart of any test socket are the contacts, as they provide signal transmission paths between the device and the test board. Proper signal transmission depends upon proper contact design and implementation.

In order to minimize losses test sockets are usually designed for specific package types and sizes. However, there are some which support multiple package types and sizes - these test sockets have an adapter type fixture which can be changed based on the package and size of the IC that needs to be tested.

Another important factor to consider when selecting a test socket is its durability or reliability. This is the number of device/IC insertions a test socket could achieve before it needs replacing. Ideally, a socket should require no repair, and operate reliably during its full life cycle. 

When testing RF/High Frequency ICs, it is important to ensure that the test socket can operate up to or above the operating frequency of the IC. As in some cases you might need to test intermodulation effects which are usually at frequencies higher than the operating frequency.