We present measurements of the complete terahertz (THz) electric near-field distribution, E(x), E(y) and E(z), in both the time- and frequency-domains, for subwavelength apertures and subsections of subwavelength aperture arrays. Measuring the individual components of the THz near-field with subwavelength spatial resolution, as they emerge from these structures, illustrates how the field intera...

A complete landscape is presented of the acoustic transmission properties of subwavelength apertures (slits and holes). First, we study the emergence of Fabry-Perot resonances in single apertures. When these apertures are placed in a periodic fashion, a new type of transmission resonance appears in the spectrum. We demonstrate that this resonance stems from the excitation of an acoustic guided ...

This paper details a preliminary investigation into space-time-waveform adaptive processing for waveform diverse distributed apertures. The large baseline of such a distributed radar results in angular resolution that is orders of magnitude better than the resolution of a monolithic system (single large radar) with the same power-aperture. This capability comes at the cost of grating lobes (mul...

We model diffraction errors found when using toothed apertures [L. P. Boivin, Reduction of diffraction errors in radiometry by means of toothed apertures, Appl. Opt. 17, 3323-3328 (1978)]. Using toothed (cf. circular) apertures minimizes diffraction by inducing destructive interference within the diffracted signal. Since diffraction effects can be quite complicated, their over-all reduction may...

This paper presents investigations on reflectarray antennas using non-periodic element distributions. The study involves the analysis and design of two reflectarrays based quasi-periodic lattices with rectangular pentagonal profiles, whose performance is compared equivalent comprised regular grids elements. characterization these performed a tailored technique for periodical quasi-periodical gr...

This paper presents electromagnetic encoders useful for chipless-RFID and motion control applications. The consist in a pair of linear chains rectangular apertures implemented by means 3D printing. One these is periodic acts as clock, whereas the other chain contains an identification (ID) code. With two aperture chains, ID code can be synchronously read, so that relative velocity between tag r...

We present a systematic design method for cylindrical conformal array of rectangular waveguide-fed metasurfaces. The metasurface consists multiple curved waveguides loaded with metamaterial elements—electrically small apertures—inserted into the upper conducting walls waveguides. Each element radiates energy free space to contribute an overall radiation pattern. Thus, geometry or electrical con...

Recent work has shown that the ability of moving contour terminators to determine the perceived motion of untextured contours is strongly constrained by whether contour terminators are classified as intrinsic (belonging to a moving contour) or extrinsic (belonging to a surface occluding a moving contour). It has also been demonstrated that stereopsis can play a decisive role in this classificat...