Similar to the dielectric characterization techniques employed in constructing high fidelity scale models, dielectric materials characterization is available using a variety of methods available at our in-house facility. Using our Bruker Fourier transform interferometer, the transmittance and reflectance of exotic and common materials can be measured between 5 and 7300 wave-numbers (150 GHz - 240 THz). Data are routinely analyzed into the material's complex dielectric constant. Tunable sources are also available from 80 GHz through 180 GHz for high dynamic range reflectance and transmittance measurements.
Staff: Andrew Gatesman, Ph.D.
To measure the complex dielectric properties of materials as well as measure the performance of microwave devices and circuits at microwave and mmw frequencies, STL uses a vector network analyzer. This gives STL the capability to measure a material's or device's microwave transmission and reflection from 10 MHz to 110 GHz. Systems have been configured to measure free-space as well as waveguide-mounted dielectrics. Currently, work is underway to detect embedded dielectric discontinuities or variations useful for modeling applications such as mine detection using ground-penetrating radars.
STL currently operates four compact radar ranges and three major material characterization systems. Operation of these systems rely, in part, on specialized optical components such as output couplers, bandpass filters, beamsplitters, etalons, attenuators, etc. STL focuses on design and fabrication of specialized materials and optics such as capacitive and inductive meshes, low-pass, high-pass, and bandpass filters, frequency selective surface, photonic bandgap materials, left-handed materials, Dällenbach absorbers, and multi-layer dielectric materials.
In order to reduce stray scatter due to unwanted target-room interactions, STL has developed a unique anechoic material called FIRAM®, which is superior by more than two orders of magnitude to other materials previously available at submillimeter wavelengths. Materials have been developed which work from 100 GHz to well into the terahertz. This material is used in a wide range of applications ranging from compact range chamber anechoics to cold loads and absorbers for radio astronomy and remote sensing satellite applications.
The anechoic chambers designed and built by the Submillimeter-Wave Technology Laboratory use our anechoics of our own custom design. Anechoics for use in the millimeter-wave and terahertz are available for purchase. Several anechoic types are available, centered at 160 GHz, 500 GHz, and 1.5 THz.
Get more information about FIRAM®.