Frequency Selected Limiters Manufacturing Development

Project No. 21-09

This Opportunity was awarded to Metamagnetics

The Department of Defense (DoD) is seeking prototype support for the Frequency Selected Limiters Manufacturing Development Project.

The Department of the Navy (DoN) uses Radio Frequency (RF) waveforms to execute the Warfighter’s mission requirements. As threats and mission requirements continue to evolve, the DoD is constantly looking to improve and upgrade its radar and Electronic Warfare (EW) system’s capabilities. An emerging capability the Warfighter is looking to include in its systems is tunable filter and tunable limiter technologies. These technologies leverage Yttrium Iron Garnet (YIG) films to provide an excellent combination of high quality (high Q) and broadband tuning range that enable the manufacturing of high-quality broadband pre-selectors and EW receiver front end applications.

Domestic manufacturing processes are immature and they vary from supplier to supplier. This immaturity and variability results in low wafer yields caused by Gadolinium gallium garnet (GGG) and/or Yttrium Iron Garnet (YIG) substrate growth defects, substrate/wafer cracking, and a lack of uniformity related to Electromagnetic (EM) properties of the devices. These domestic process variances result in a dismal production yield of approximately 50 percent.

The lack of reliable domestic manufacturing technology maturity creates challenges for technology adoption and transition to DoD programs. It also drives up production costs. Developing affordable substrate film growth processes for Frequency Selected Limiters (FSLs)  / Auto-tunable Filters (AtF) (FSL/AtF) devices used in microwave DoD applications will require reliable domestic manufacturing capability and capacity. This will require greater uniformity and reproducibility to deliver cost-effective high yield GGG and YIG substrates for use in FSL/AtF devices. Through high yield GGG and YIG substrates growing processes, cost reductions for FSL/AtF end items will be realized. The establishment of domestic manufacturing capability of microwave FSL/AtF devices for a wide range of DoD microwave applications requires domestic manufacturing improvements to increase production throughput.

While YIG films can be applied to multiple substrate materials, GGG has been shown to excel supporting YIG films since their lattice structures are well aligned. Growing the GGG substrates is challenging and that process is not available domestically.

The purpose of this prototyping project is to support establishing a domestic source for GGG substrates that align with the manufacturing of YIG Auto-tunable Filters (AtF) and Frequency Selected Limiters (FSLs) so the upgrade and deployment of higher power and wide bandwidth radar and EW systems can be expedited and built domestically.

The desired end state is a refined microwave device manufacturing process for GGG film growth technology that reduces the density of defects and variation in material properties within individual films and from batch to batch.