A key component of such systems is the circulator, a device found in the Simultaneous Transmit And Receive circuitry. Conventional circulator designs rely on magnets positioned on either side of the device. These magnets tend to be large and heavy, and add significant cost. Thousands of them are needed for the most advanced radar systems. As a result, radar platforms can weigh several tons and take up a lot of space on host aircraft and ships.
It turns out magneticceramic thin films have what is called a spontaneous magnetic moment. This moment is sufficient to eliminate the circulator magnets. A screenprinting process inexpensively makes the millimeter-thick films of Ba-hexaferrite. Researchers are now working on prototypes and hope to have the technology ready for deployment by 2008. Funding for the research comes from the Office of Naval Research as part of the "Navy After Next" initiative, Darpa, and the National Science Foundation.
