RF Terminations or loads absorb incident power at a port with minimal reflection, minimizing signal reflection back into the circuit or system. This is done by terminating the port in its characteristic impedance. Any multi-port RF system, whose ports are not all being used should be terminated so that there are any signal incident on these ports will be absorbed. These are used in couplers, hybrids, isolators, test equipment and in systems where a port needs to be terminated.

Selecting RF Terminations

When selecting a RF termination it is important to know the parameters that you need to specify. Below are a list of the key parameters to look out for when selecting a termination:

Impedance: This is the most important characteristic of a termination. This is the characteristic impedance of the port that needs to be terminated. The impedance value of the termination must match the characteristic impedance of the port being terminated. 50 Ohm termination are the most common, followed by 750 Ohms and then custom values based on the system requirement.

Power (W): This is the power level that can be adsorbed by the termination while maintaining its electrical characteristic.

VSWR & Return Loss: These measure the reflection of the signal back into the circuit. Ideally there should be no reflection, however in the real world this is not the case. The VSWR and Return loss are measures of the amount of reflection in a termination.

Package Type: Termination are available in surface mount form factor as well as connectorized modules with a number of connector options – SMA, BNC, N Type etc.