Tuesday, August 17, 2010

A Through-Dielectric Radar Imaging System, this month in Trans. on AP-S



Good news: my article in Transactions on Antennas and Propagation has been published. It is titled, 'A through-dielectric radar imaging system.' If you would like to read it click here.

A photo of the experimental setup is shown above. Yes, the measurements were made in my backyard :) The modeling and simulations were developed while i was a graduate student at the Michigan State University Electromagnetics Research Group. The radar system was built in my basement and my garage. This project shows you that you can build PhD level projects in your own backyard.

To learn more about the modeling and this radar system please see the project page.

Here is the abstract:

Through-lossy-slab radar imaging will be shown at stand-off ranges using a low-power, ultrawideband (UWB), frequency modulated continuous wave (FMCW) radar system. FMCW is desirable for through-slab applications because of the signal gain resulting from pulse compression of long transmit pulses (1.926–4.069 GHz chirp in 10 ms). The difficulty in utilizing FMCW radar for this application is that the air-slab boundary dominates the scattered return from the target scene and limits the upper bound of the receiver dynamic range, reducing sensitivity for targets behind the slab. A method of range-gating out the air-slab boundary by significant band-limiting of the IF stages facilitates imaging of low radar cross section (RCS) targets behind the slab. This sensor is combined with a 1D linear rail and utilized as a rail synthetic aperture radar (SAR) imaging system. A 2D model of a slab and cylinder shows that image blurring due to the slab is negligible when the SAR is located at a stand-off range of 6 m or greater, and thus, the two-way attenuation due to wave propagation through the slab is the greatest challenge at stand-off ranges when the air-slab boundary is range-gated out of the scattered return. Measurements agree with the model, and also show that this radar is capable of imaging target scenes of cylinders and rods 15.24 cm in height and 0.95 cm in diameter behind a 10 cm thick lossy dielectric slab. Further, this system is capable of imaging free-space target scenes with transmit power as low as 5 pW, providing capability for RCS measurement.