In mobile communication, a less explored technique to mitigate fading effects is based on the physical parameter of the transmitter by varying the physical dimension of the transmitting antenna. This paper deals with a self adaptive system to eliminate severe fading effects in different multi antenna set-ups by adaptively updating the effective aperture of the transmitting antenna. The system c...

In this paper, we report the mode area scaling of a rare-earth doped step index fiber by using low numerical aperture. Numerical simulations show the possibility of achieving an effective area of ~700 um² (including bend induced effective area reduction) at a bend diameter of 32 cm from a 35 μm core fiber with a numerical aperture of 0.038. An effective single mode operation is ensured followin...

INTRODUCTION: Historically, tibial tunnel creation in ACL reconstruction was performed by antegrade insertion of a tibial guide pin followed by antegrade reaming from the anteromedial tibial metaphysis (distal aperture) to the tibial plateau (proximal aperture). In the last few years retrograde reaming has been introduced.[1, 2] It has been theorized that the retrograde tibial tunnel drilling t...

   In this manuscript, a solar cavity packed with thermoelectric generator modules is investigated numerically. The hot plate of TEG modules make the inner surface of the cube, and the cold plate is outside of the cavity, under natural convection. The TEG modules are electrically in series. The solution algorithm using the equations of heat transfer and generated power of TEG modules is d...

The purpose of this study was to evaluate the use of diverging-cut aperture to minimize collimator contamination in proton therapy. Two sets of apertures with nondivergent and divergent edge were fabricated to produce a 10 cm × 10 cm field at the radiation isocenter of a single-room proton therapy unit. Transverse profiles were acquired in a scanning water tank with both aperture sets. Up to 9....

National Institute of Standards and Technology, Gaithersburg, MD 20899-0001 This paper presents the results of heat flux sensor calibrations in two blackbody facilities: the 25 mm variable temperature blackbody (VTBB) primary facility and a recently developed 51 mm aperture spherical blackbody (SPBB) facility. Three Schmidt-Boelter gages and a Gardon gage were calibrated with reference to an el...

Abstract Due to the weak power of Terahertz sources, metal tips are often used enhance signal intensity scattering scanning near-field optical microscope (THz s-SNOM). However, while enhancing near-field, also affect field distribution on sample surface. In this paper, a home-built 97.8GHz sub-Terahertz imaging system was image graphene disks with dozens microns in diameter. It found that signi...

For microwave imaging systems that utilize antennas with spatially separated feeds and apertures, arrival time correction based on the antenna aperture location is one of the fundamental steps in radar data processing. The estimates of the antenna aperture time and the corresponding average velocity in the material in contact with the antenna are expected to have a significant impact on the qua...

Sparse aperture imaging provides the opportunity to achieve high resolutions image with groups of smaller apertures rather than a large single aperture. Eliminating large monolithic apertures provides both a cost and weight reduction among other possible benefits. Imaging with sparse apertures requires that both amplitude and phase of the incident field be captured so that an effectively larger...