Research and Teaching Facilities

        75-110 GHz Fully Polarimetric Bistatic Scatterometer

MMW System

The millimeter-wave (MMW) bistatic scatterometer at the University of Washington is based on the HP8510C MMW vector network analyzer (VNWA). Extensive modifications were made to the front-end part of the system to convert it to a fully polarimetric scatterometer setup. The HP83621 synthesized frequency sweeper generates a microwave signal from 12.5 to 18.3 GHz. The amplified and frequency-leveled microwave signal is then multiplied by 6 to the MMW frequency, 75-110 GHz. In a fully polarimetric operation, the transmitted signal polarization is controlled by a rotational angle of a lambda/2 wave plate in front of the transmitting antenna. The two orthogonal polarizations received by the dual-polarized receiving antenna are down converted by harmonic mixers.

Positioning Systems

Both Tx and Re antennas are mounted on the stepping-motor-controlled Scientific Atlanta stages. The Re antenna can be moved from -100 to +100 degrees with an angular resolution of less than 0.1 degrees. This allows the users to conduct both transmission and near-grazing experiments with the same system. The Tx antenna stage can be moved so that the receiver can be placed at any point on a hemispherical shell surrounding the sample. The sample is mounted on the rotational or translational stage and placed at the center of rotation of the Re antenna. The maximum size is 1 meter in diameter and 20 cm in thickness.

CAD/CAM Rough Surface Fabrication System

CAD/CAM Rough Surface Fabrication System

We have a unique capability of fabricating rough surfaces of different surface parameters. Our system consists of surface generation software and a CAD/CAM system. The milling machine has a resolution of less than 10 mm. The maximum surface size that can be fabricated with this system is approximately 20x30.


Optical System

Optical System

A complete bistatic and fully polarimetric optical scattering system is also available for this project. This system is mounted on a 4x8 optical bench and the data acquisition is completely controlled by computer. A 4x4 complete Mueller matrix is obtained by transmitting 4 different polarizations and measuring the scattered intensity using 6 different polarizers.


Microwave , MMW Material Characterization

We have extensive microwave equipment including Agilent/HP vector network analyzers (8510C, 8720E, 8722ET), an antenna range, and anechoic chamber. Our antenna range has been used for both teaching microwave classes and research involving the design of antennas.   We have also developed a 75-110 GHz fully polarimetric bistatic scatterometer, 30-40 GHz radar, and circular microwave imaging systems. We have also developed hardware and software for microwave/millimeter-wave material characterization systems. These systems can be used for our experiments to verify our theoretical results.  We have computer facilities for our numerical work on Monte-Carlo simulations, integral equation solutions, imaging, and metamaterial research.

 

Microwave probe station for material and device characterizations.

 

Random rough surface created by computer-controlled surface milling machine.

 

      

Left: Anechoic chamber and antenna measurement system.  Right: W-band (75-110 GHz) and V-band (50-75 GHz) systems for transmission and reflection measurements.

 

Millimeter-wave bistatic measurement system