October 11, 2005 – Technology Breakthrough Enables Low Loss Tunable Microwave Devices on Cost-Effective Commercially Scaled Substrates
nGimat, a leading manufacturer and innovator of engineered nanomaterials, today announced the availability of a family of continuously variable phase shifters utilizing epitaxial BST films. The phase shifters operate at L, S, and C-band at frequencies covering 700 MHz to 7GHz with a minimum phase shift of 90 degrees and a minimum relative bandwidth of 30 percent, and with the ability to produce higher frequencies. The primary applications for these phase shifters include broadband, satellite communications, phased array radar and smart antennas.
With the pervasive growth of electronic communication systems in the military, commercial and public safety marketplaces, there is an increasing demand for low cost devices with reduced size, weight and power yet with added functionality and superior performance, said Dr. Andrew Hunt, CEO of nGimat. Using our proprietary CCVD process, nGimat has grown epitaxial BST films on inexpensive sapphire substrates and developed a planar low-voltage capacitor structure with improved power handling capability. The breakthrough makes possible the commercialization of low loss tunable microwave devices at low costs on commercially scaled substrates.
About nGimat’s Analog Ferroelectric Phase Shifters
While ferroelectric BST materials exhibit unique characteristics suited for microwave applications, there are a number of problems that have impeded the progress made on BST tunable devices including 1) high loss attributed to poor crystalline quality, 2) the required DC bias voltage was too high (~100 V) or IMD was too low, and/or 3) the high costs associated with making high-quality, large-area BST. nGimat has developed a process of making highly epitaxial BST films on commercially practical sapphire wafers, which demonstrate low loss and high tunability. A proprietary low-voltage (<20V) capacitor structure was designed and fabricated, which displays improved IMD performance.
To maximize performance and minimize processing cost, BST films are deposited smooth, dense and epitaxial onto sapphire substrates using nGimat’s proprietary combustion chemical vapor deposition (CCVD) process. Phase shifters fabricated on these BST coated sapphire substrate have a footprint of www.ngimat.com. Samples are available upon request.
The Georgia Institute of Technology was instrumental in the development of nGimat’s next-generation ferroelectric BST phase shifters, and the projects were supported by the Air Force Research Lab and the National Science Foundation SBIR programs.