Figure 4
The illumination bandwidth can be exploited to generate multispectral microwave images.
The reflectance properties of five sub-wavelength wire resonators of decreasing length are shown. In (A) there are five wires of decreasing length (L to R: 17.5 mm, 15 mm, 12.5 mm, 10 mm and 7.5 mm) placed vertically in styrofoam (which is transparent in the X-band). In (B) a gray scale linear intensity image is shown (full 5 GHz bandwidth). In (C) a multi-spectral image is shown where the primary colors red, green and blue represent the lower, middle and upper frequency bands of illumination, respectively. The smaller wires are not as reflective of the longer wavelengths, causing them to appear bluer. The individual frequency band images are shown in (D–F).
