There are often occasions with RF signal chains where it is desirable to prevent the RF energy in that signal chain from either continuing along the signal chain or from exiting a given port. Given the nature of RF transmission lines, a simple short or open port will result in undesirable reflections and even signal emissions. Hence, it is often crucial to use RF Terminations to safely and securely absorb the excess signal energy while protecting other components in the signal chain from potentially harmful reflections that could cause interference or even damage. An example of this is when the transmission of a radar signal needs to abruptly stop by the time required to shut down the RF signal would take longer than the desired shut-off window. In this case, a switch can be placed in the transmission signal chain that redirects the output of the transmitter to a termination.
For legacy radars, the RF termination used in a radar application would need to be very high power. With the growing prevalence of smaller and more portable radar systems and communication systems, there is a growing need for Low-Power RF Terminations. A couple of factors are leading to this. With multi-input multi-output (MIMO) and beamforming technology there are typically many more signal paths feeding antenna elements than with previous radar and communication technologies that used a single higher power signal path. With a multitude of lower power signal paths, it is now possible to terminate these paths with low-power RF terminations. However, the higher number of signal paths also means that there needs to be a larger number of terminations available to terminate these ports.
Low power RF terminations are also extensively used with test and measurement applications. Many pieces of RF test equipment have exposed ports and benefit from having quality Coaxial Terminations at those ports. Moreover, there are many components and devices commonly used in RF tests that require RF terminations for some test setups, such as with directional couplers where only either the forward or reverse signal is needed.
As there is a plethora of various coaxial connector types, there are RF terminations made with each coaxial connector type. This includes push-connect type coaxial connectors, such as SSMC, SMP, SMC, SMB, etc.
With the growing interest in developing upper millimeter-wave technologies, there is a rising need for RF coaxial terminations that reach beyond 40 GHz. This is why 3.5 mm, 2.92 mm, 2.4 mm, and 1.85 mm are becoming increasingly available.