Ferrite Substrate from Metamagnetics Enables New Capabilities for Defense Communications

Leveraging its expertise in ferrite materials and wireless communications, Massachusetts-based Metamagnetics is bringing new capabilities to military forces and defense contractors seeking improved designs and deployment for their radio frequency and microwave systems – able even to withstand the extreme forces of missile launches where permanent magnets have been known to shake loose. 

Special ferrite substrate serves as the magnet for Metamagnetics circulators/isolators 

The company has developed a ferritic substrate which enables it to make robust, high-performance and miniaturized self-biased RF and microwave circulators and isolators for mission-critical military networks. The devices enable developers to produce high power radar and communication systems that achieve their goals for size, weight, power and cost reductions while also enabling a variety of novel system design and surface mount installation approaches. 

As depicted in the image at top, the innovative material is created by aligning its magnetic grains and then processing it at high temperatures to create an ultra-dense compact that is free of defects and voids—and which ultimately acts as a magnet itself. 

Anton Geiler, Metamagnetics president 

“Using this material as the basis for our self-biased RF/microwave circulators and isolators, we have been able to demonstrate 90% reduction in size and weight over traditional microstrip permanent magnet isolators and circulators,” according to Anton Geiler, president. “Offering planar and monolithic construction, our innovative devices also withstand levels of shock and vibration that far exceed those attainable by microstrip permanent magnet solutions whose magnets are known to detach under harsh conditions, such as missile launches.” 

Removing the permanent magnet that is found in traditional circulators and isolators allows the components to be significantly smaller in size, faster and more durable, says the company. Also important for military customers, supply chain risks are reduced since the locally produced isolators and circulators use readily available raw materials rather than rare-earth metals.  

Metamagnetics Auto-Tune Filter 

Another product from the company that utilizes its special material is the Auto-Tune Filter. This device automatically attenuates interfering signals above a certain threshold, despite having fewer parts and being small in size compared to standard designs.  

The company’s self-biased circulators and isolators have a high frequency range and can be used in a wide variety of commercial and military applications including radar, wireless, and satellite communications. Examples include military target tracking, automotive intelligent cruise control and collision avoidance, 5G high capacity, gigabit-speed wireless and WiFi systems, and satellite-based surface water and ocean topography. 

The biasing rare-earth magnet in a traditional circulator or isolator can be up to 90% of the component size. Without the magnet, however, the component can be smaller, allowing more space to adapt circulators and isolators for higher frequency. Missiles, UAV’s and space systems are weight-sensitive to the gram, and the magnets associated with traditional circulators exacerbate this problem. Metamagnetics says it has achieved a 95% reduction in component weight with the self-biased design by eliminating the dependency of the rare-earth biasing magnet. 

Robustness is another key factor. A traditional circulator has its magnet attached by an epoxy in order to set the operating frequency. This can create a significant problem in any application with high shock or vibration. According to Metamagnetics, its self-biased circulators have been tested to survive over 50,000 Gs, enabling new communication platforms for small form factor munitions. 

Located in Westborough, the company began as a spin-out from the Northeastern University Center for Microwave Magnetic Materials & Integrated Circuits (CM3IC) which is recognized as a leading R&D institute in microwave and mm-wave ferrite materials, metamaterials and multiferroics. For more info, see www.mtmgx.com