RF Circulator

This page covers rf circulator basics and provide link to manufacturers of rf circulator.

It is a passive device, does not require any power to operate. It usually will have 3 or 4 ports and pass signal from one port to the next in any one direction either clockwise or anticlockwise. RF circulators are made up of magnetically biased ferrite material.

One of the application of RF circulator is using single antenna for both the transmitter and receiver. As mentioned in the figure, this is counter clock wise circulator hence directional of interface is between port1->port2, port2->port3 and port3->port1. Transmitter connected at port1 can send data using antenna connected with port 2 and received data from antenna is passed to receiver connected at port3. Hence due to this functionality of transmission and reception using one antenna circulators are also referred as duplexer. RF or microwave circulators are very essential for RF test and measurement systems. If port 3 is terminated then RF circulator becomes isolator because port 2 to port 1 offers reverse isolation.

rf circulator

RF Circulators are of three main types viz. drop-in circulator, coaxial circulator and waveguide circulator as mentioned in the figures below. There are adaptors avaiable to convert between coaxial and waveguide circulators.

RF Circulator specifications

•  Frequency range: 0.8-2.0 GHz
•  Insertion Loss between ports: 0.5dB
•  Reverse Isolation between ports: 20dB
•  VSWR at individual ports: 1.2dB
•  Average power: 50W
•  Operating Temperature: -30 to +75°C

RF Circulator with high isolation and low insertion loss is best choice for the buyer. These type of RF circulator delivers high performance accuracy in the test and measurement system.

As mentioned in the technical specifications there are circulators designed for different frequency ranges. Also roughly circulator return loss should be equal to Isolation. In this case isolation is 20dB and return loss is 20.828(VSWR of 1.2)


•  RF circulator is used to control flow of RF signal in the direction of interest.
•  Sharing single resource, example-using single antenna between Tx and Rx.

Popular manufacturers

•  DiTom Microwave Inc. contact sales@ditom.com to buy. Manufacturer of RF circulators operating at frequencies from 300 MHz to 40 GHz for both military and commercial applications.
•  Pasternack
Refer our page on RF CIRCULATOR vendors, suppliers, Manufacturers.

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