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Self-Biased Circulators and Isolators

Self-Biased Circulators and Isolators


At Ka band, the biasing magnet of traditional circulators and isolators attributes to 90% of the component size and this problem is augmented as you move up in frequency and the magnet becomes an even larger portion of the device. By the time you reach 20 GHz in frequency a traditional circulator can no longer fit in the array spacing for phased array radar systems. Our planar, self-biased circulators not only save space, but enable novel RF system layouts such as stackable TR modules. An array system may contain over 10,000 of these components resulting in monumental gains to the overall architecture as the size of individual components is reduced.


UAVs, missiles and space systems are weight-sensitive to the gram. By eliminating the biasing magnet required by traditional devices, Metamagenetics has achieved a 95% reduction in component weight. This provides additional benefit to airborne platforms where weight is a factor of system design.

Resistant to shock and vibration

To avoid interference with the circuitry, a traditional circulator has its magnet attached by a weak epoxy. This creates a significant problem in any application with high shock or vibration. For example, in a standard rocket launch, it is expected for a large number of these components to fail. Metamagnetics self-biased circulators have been tested to survive up to 50,000 Gs. Not only does this eliminate the problem of component failure in missile and rocket systems, but our devices now enable new communication platforms for small caliber projectiles as well.

End to rare-earth dependancy

The composition of the biasing magnet found in traditional circulators is typically the rare earth metals NdFeB (Neodinium Iron Boron) or SmCo (Samariam Cobalt). Unfortunately the majority reserves of these compounds are found in China. Without the magnet, Metamagnetics self-biased circulators eliminate this dependency making them an ideal candidate for defense applications.


A re-engineered product design has enabled Metamagnetics to remove many of the costly steps in the manufacturing process. This creates a circulator with enhanced performance and functionality while boasting a highly competitive price point.

Key Characteristics:

  • Composed of advanced self-biased materials fabricated without rare-earth elements
  • Maximum isolation without compromise to micro- and millimeter-wave frequencies (Ku band and beyond)
  • Ideal for weight-, size- and cost constrained systems
  • Alleviate problems in high shock or vibration environments

Side by side comparison of a Ka band magnetic biased circulator (left) next to our self-biased circulator (right). Note without a biasing magnet our circulator sits completely flat and is 90% smaller. A phased array radar system can have 5,000 to 10,000 of these components, making SWAP a major concern.

Contact us today to learn more about our self-biased circulators and isolators. Our team of experts can help you find the best fit with a pre-existing component or a custom designed solution to meet the most rigorous specifications of both DOD and commercial customers.


Please direct all sales and informational inquiries to (617) 833-2950.