Title: Miniaturized, low-cost, self-biased circulators for space and airborne applications
Presenting Author: Trifon Fitchorov
Organization: Metamagnetics
Co-Author(s): Anton Geiler, Ogheneyunume Obi, Michael Geiler, Lee Burns, Matthew Boudreau

Abstract:
Circulators reduce the number of components used for communications, as they enable using one antenna for both transmit and receive functions in a T/R module. Reduced component count leads to lower cost and enables increased payload. Using an innovative approach, Metamagnetics has exploited the exceptional properties of low loss ferrites prepared using Metamagnetics' proprietary processing procedure, that eliminates the need for large, heavy, and expensive external permanent magnets, enabling a small, light and sturdy self-biased circulator. The absence of a permanent magnet provides the self-biased circulator with exceptional shock and vibration tolerance, avoiding magnet 'pop-off' at launch. Moreover, the use of the low-loss ferrite material leads to improved supply chain security, as the magnets used in conventional circulators are made of expensive imported rare-earth elements. The self-biased technology enables miniaturization, reduction in weight (> 90%) and cost (> 30%), shock tolerance, quick production cycle, and high-performance. These properties make the self-biased circulator a desirable electronic component with a wide range of applications in communications, small satellites, UAVs, and phased arrays, among others. Metamagnetics has developed self-biased circulators that operate in the Ku through Ka frequency bands and are characterized by insertion loss lower than 1 dB, isolation greater than 20 dB, and bandwidth of up to 12 %. Development has been funded by NASA SBIR programs and through a NASA ACT grant with the goal of integrating the self-biased circulator into various NASA satellites and Earth Science missions, such as NASA SCaN, NASA ACE, and the TDRS satellite.