How RF Isolator Works | How does an RF Isolator work

This page describes RF Isolator working operation. It mentions how RF Isolator works along with its terminal diagram. As we know Ferrite isolator plays very fundamental role in RF and microwave systems.

Isolator is a passive ferrite device which allows energy to pass in one direction only and prevents any reflections to travel in the other direction. It is known as traffic conductors of the RF energy as designed by the RF system engineer. It helps in routing the RF signal in desired direction in RF circuit designs such as RF transceiver, RF Power Amplifier, RF LNA etc.

rf isolator function

➤Let us understand how rf isolator works.
➤RF isolator is similar to diode functionally, but unlike diode which passes current in one direction only, isolator passes RF energy in one direction.
➤When any one port of a 3 port circulator is terminated with 50 Ohm, it becomes Isolator.
➤As shown the device has two ports viz. port-1 and port-2. It allows signal from port-1 to port-2 with minimum attenuation and signal from port-2 to port-1 with maximum attenuation.
➤Moreover any RF energy which enters from port-2 will get routed towards matched termination connected on the port-3. This gets dissipated as heat. Hence any reflections from port-2 to port-1 is eliminated. This prevents any damage to signal source or equipment connected on port-1.

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