Non-mechanical beam steering using reflection-mode readout of volume gratings in a photorefractive material

2020 ◽  
Author(s):  
Austin Scott ◽  
Partha P. Banerjee ◽  
Jonathan Slagle
Keyword(s):  
Beam Steering ◽  
Reflection Mode ◽  
Photorefractive Material ◽  
Volume Gratings

An improved design for an Scanning Tunnelling Microscope (STM) for use in a Transmission Electron Microscope (TEM)

1991 ◽  
Vol 49 ◽  
pp. 384-385
Author(s):  
W.K. Lo ◽  
J.C.H. Spence
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Mechanical Stability ◽  
Scanning Tunnelling Microscope ◽  
Reflection Mode ◽  
Specimen Holder ◽  
Transmission Electron ◽  
Scanning Tunnelling ◽  
Improved Design

An improved design for a combination Scanning Tunnelling Microscope/TEM specimen holder is presented. It is based on earlier versions which have been used to test the usefulness of such a device. As with the earlier versions, this holder is meant to replace the standard double-tilt specimen holder of an unmodified Philips 400T TEM. It allows the sample to be imaged simultaneously by both the STM and the TEM when the TEM is operated in the reflection mode (see figure 1).The resolution of a STM is determined by its tip radii as well as its stability. This places strict limitations on the mechanical stability of the tip with respect to the sample. In this STM the piezoelectric tube scanner is rigidly mounted inside the endcap of the STM holder. The tip coarse approach to the sample (z-direction) is provided by an Inchworm which is located outside the TEM vacuum.

Symmetric-pair antennas for beam steering, direction finding or isotropic-reception gain

1991 ◽  
Vol 138 (4) ◽  
pp. 368 ◽  
Author(s):  
R. Benjamin ◽  
W. Titze ◽  
P.V. Brennan ◽  
H.D. Griffiths
Keyword(s):  
Beam Steering ◽  
Direction Finding ◽  
Symmetric Pair

Electromagnetically Driven 2-axis Optical Beam Steering MEMS Mirror and Its Dependence of Actuation on Magnetic Field

2010 ◽  
Vol 130 (4) ◽  
pp. 107-112 ◽  
Author(s):  
Yoshiyuki Watanabe ◽  
Yutaka Abe ◽  
Shinnosuke Iwamatsu ◽  
Seiya Kobayashi ◽  
Yoshiyuki Takahashi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Beam Steering ◽  
Optical Beam

An Optimized Scheme for Optical Phased Array Beam Steering Controlled by Wavelength

PIERS Online ◽  
2007 ◽  
Vol 3 (2) ◽  
pp. 127-131 ◽  
Author(s):  
Ying Zhao ◽  
Xiaozhou Yang ◽  
Qin Cai ◽  
Weiwei Hu
Keyword(s):  
Phased Array ◽  
Beam Steering ◽  
Optical Phased Array

scholarly journals Low-complexity beam-domain channel estimation and power allocation in hybrid architecture massive MIMO systems

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Xiao Chen ◽  
Zaichen Zhang ◽  
Liang Wu ◽  
Jian Dang
Keyword(s):  
Channel Estimation ◽  
Power Allocation ◽  
Spectral Efficiency ◽  
Communication Systems ◽  
Mimo Systems ◽  
Beam Steering ◽  
Estimation Method ◽  
Low Complexity ◽  
Estimation Accuracy ◽  
Hybrid Architecture

Abstract In this journal, we investigate the beam-domain channel estimation and power allocation in hybrid architecture massive multiple-input and multiple-output (MIMO) communication systems. First, we propose a low-complexity channel estimation method, which utilizes the beam steering vectors achieved from the direction-of-arrival (DOA) estimation and beam gains estimated by low-overhead pilots. Based on the estimated beam information, a purely analog precoding strategy is also designed. Then, the optimal power allocation among multiple beams is derived to maximize spectral efficiency. Finally, simulation results show that the proposed schemes can achieve high channel estimation accuracy and spectral efficiency.

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