Visual Observation and Quantitative Measurement of the Microwave   Absorbing Effect at X band
  We have setup a simple field mapping measure system to describe graphically the 2D quasi-free-space electromagnetic wave in a parallel plate waveguide at the X-band frequencies. Our apparatus illustrates a potential application in characterizing the microwave absorbing materials. The visual demonstration about the physical process and quantitative measurement of reflectivity coefficients can be achieved. This simple apparatus has have an advantage over with conventional testing methods which usually involve huge, expensive anechoic chambers and demand samples of large size. 
L. Zhao, X. Chen, C. K. Ong