Ultra-fast Broadband Low-cost T/R Switches based on Vanadium Dioxide Metal-insulator Transition Materials
Navy SBIR FY2013.1

Sol No.: Navy SBIR FY2013.1
Topic No.: N131-031
Topic Title: Ultra-fast Broadband Low-cost T/R Switches based on Vanadium Dioxide Metal-insulator Transition Materials
Proposal No.: N131-031-0436
Firm: Metamagnetics Inc.
480 Neponset Street
Canton, Massachusetts 02021-1938
Contact: Andrew Daigle
Phone: (781) 562-0756
Web Site: www.mtmgx.com
Abstract: Over the course of this small business innovative research (SBIR) phase 1 (Ph1) program Metamagnetics proposes the development of next generation ultra-fast and broadband T/R switches with high isolation (>30 dB) based on thin films of vanadium dioxide (VO2) metal-insulator transition (MIT) materials produced via pulsed laser deposition method. The crystalline uniformity of these films will be strictly monitored via controlled deposition parameters including oxygen pressure, substrate distance from target, and laser power. This will ensure the best quality oxide films as in the fabrication of T/R switches crystalline uniformity as well as the design of the R/F microwave switch have both been shown to be crucial elements of the switching speed and isolation bandwidth performance. In fact, sub pico-second responses have been theorized for VO2 based T/R switches when more efficient RF microwave designs are utilized which is a marked improvement over existing MEMs and GaN T/R switch technologies. Other advantages of switches based on VO2 MIT materials include low fabrication costs, low insertion losses, and high isolation over broad bandwidths of operation. Together, these attribute make the development of VO2 switches based on MIT materials a very attractive solution for next generation T/R switch applications.
Benefits: Microwave switches fabricated on GaAs are integral component of T/R modules and have been the "go-to" RF/microwave switch since the 1980s. It was at this time that MMIC circuits became readily available at low prices with greatly improved reproducibility. These field-effect transistors (FET) have remained popular due to their low power operation, small size and design simplicity. However since the existing technology is mature at this point and costly to produce, overwhelming improvement to device performance is unlikely. Due to this, alternative switch technologies such as Silicon-on-Sapphire (SOS), Silicon-on-Insulator (SOI), and MEMs are gaining market share with the MEMs market alone exceeding $650 USM in 2012. Metamagnetics proposed T/R switches are similar to novel SOI/SOS technologies, in that they are based on vanadium oxide metal-insulator transition materials however they utilize single crystal sapphire substrates. The low-cost nature of these substrates in recent years has been linked to developments in the LED industry where the number of substrates sold exceeded 120 billion units in 2012. This growth is expected to continue in the future, making sapphire substrates the go-to single crystal substrates for next generation low-cost devices applications.