A valuable tool for terminating any unused port or signal chain that may produce more energy than can be safely handled within the system is a high-power RF termination. RF terminations are used to absorb unwanted RF signal energy and convert that energy into heat. A key aspect of high-power RF terminations is the ability to absorb the energy directed to them with minimal reflections. With the rise of sub-6 GHz wireless applications, especially extended range communication and sensing, components such as high-power RF loads that operate to 6 GHz, are extremely useful in the laboratory and in the field.
There are many situations in communications and sensing applications where the RF energy from a transmitter needs to be stopped prior to other communication or sensing functions. This could be for radars with a switched front-end or for communication transmitters with a switched filter bank output. Other examples included when a communication or sensing circuit needs to go silent as quickly as possible or if a part fails and there is excess signal energy in the signal chain that needs to be safely dumped or it could damage other components. In the laboratory, there are many cases where a given signal path may need to be terminated while live during a test setup before being used, or the signal energy used in testing a device needs to be terminated when an output is switched. Some components and devices involved in high power signal chains may also need to be terminated with a high-power RF termination, such as directional couplers, circulators/isolators, hybris, signal generators, test transceivers, transmitters, etc.
This is why it is important for a high-power RF termination to be able to handle the sustained input power and peak input power while providing good VSWR across the frequency band of operation. For cellular systems, Satellite Communications (Satcom), distributed antenna systems (DAS), test/measurement, and radar, the common sub-6 GHz coaxial standards include DIN 7/16, 4.3-10, and N-type. Though there are other coaxial standards that operate in this frequency range and are commonly used for these applications, these coaxial standards are capable of carrying higher power levels and are more appropriate to high power RF terminations than an SMA, for example. Where a typical RF termination can handle a couple of watts of RF energy within the operation frequency range, high power RF terminations are typically designed to handle 5 Watts, 10 Watts, 50 Watts, or more.