What is an RF Load and where are RF Terminations used?
RF terminations/RF loads are fundamental components used throughout an RF signal chain in virtually all RF applications from test and measurement to military and aerospace. Essentially, RF loads, and terminations describe the same type of component, which is a passive component that absorbs the RF energy at the terminus of a signal chain branch. In most applications, an RF termination presents a load impedance that is identical to the intrinsic impedance of the transmission lines used in the interconnect between the termination and the upstream component/device. In this way an open-end or unused port, such as an unneeded forward or reverse port in a directional coupler, can be terminated so that it prevents unwanted reflected signals from returning from the termination and impacting upstream signal chain components.
RF Terminations/loads come in a variety of types for both coaxial and waveguide interface types. One of the main defining features of RF Terminations is the specific coaxial type or waveguide size, as well as the power handling capability of the termination. In general, the power handling capability is limited by the coaxial or waveguide connector type, the type of RF load within the termination, and the thermal management design of the termination. Some RF Terminations have additional features, such as a retention chain, environmental sealing gaskets, and specific metal plating to enhance the corrosion resistance. Though not typically available for every Coaxial RF Termination type, some Coaxial RF Terminations are also made double ended with a different coaxial connector type on each end. This feature allows for termination of multiple coaxial connector ports without an additional termination or coaxial adapter. The following are key RF termination performance parameters:
Key RF Termination Performance Parameters:
- Impedance
- Power (W)
- VSWR
- Return Loss (dB)
- Package Type
- Power Handling
- Interconnect Interface
- Size
- Weight
- Environmental Ratings
- Operating Temperature Range