Optical fabrication of organic nonlinear DAST crystals for high frequency modulation

2003 ◽  
Author(s):  
Yoshiharu Namba ◽  
Sho Koyama ◽  
Hiromasa Ito ◽  
Young-Mok Son ◽  
Naoki Ohsaki
Keyword(s):  
Frequency Modulation ◽  
High Frequency ◽  
Optical Fabrication

High-frequency modulation of twin-stripe semiconductor lasers

2003 ◽  
Author(s):  
Edeltraud Gehrig ◽  
Nicoletta Gaciu ◽  
Markus Pessa ◽  
Ortwin G. Hess
Keyword(s):  
Semiconductor Lasers ◽  
Frequency Modulation ◽  
High Frequency

High-Frequency Modulation of GaAs/AlGaAs LEDs Using Ga-Doped ZnO Current Spreading Layers

2014 ◽  
Vol 35 (1) ◽  
pp. 36-38 ◽  
Author(s):  
Shang-Fu Chen ◽  
He-Long Syu ◽  
Chi-Chen Huang ◽  
Yueh-Lin Lee ◽  
Chong-Long Ho ◽  
...  
Keyword(s):  
Frequency Modulation ◽  
High Frequency ◽  
Current Spreading ◽  
Doped Zno

scholarly journals Analytical, FEA, And Experimental Research of 2D-Vibration Assisted Cutting ( 2D-VAC) In Titanium Alloy Ti6Al4V

2021 ◽  
Author(s):  
Rendi Kurniawan ◽  
Farooq Ahmed ◽  
Gun Chul Park ◽  
Tae Jo Ko
Keyword(s):  
Residual Stress ◽  
Plastic Strain ◽  
Cutting Force ◽  
Frequency Modulation ◽  
High Frequency ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Von Mises Stress ◽  
Micro Hardness ◽  
Micro Structure

Abstract In the 2D-Vibration Assisted Cutting (2D-VAC) method, the cutting tool shakes in a 2-dimensional approach because of superimposed high-frequency modulation. This high-frequency modulation effect creates a displacement at a tiny scale of micrometers and causes an escalation in the resultant cutting speed. Consequently, 2D-VAC has superior advantages compared to traditional cutting (TC). This manuscript describes research on 2D-VAC that focuses on modeling cutting forces (mathematical model) and finite element analysis (FEA) results. The FEA results are focused on the von Mises stress, plastic strain, cutting force, cutting temperature, and residual stress. In addition, an experiment for the chip formation, micro-structure layer, and micro-hardness was also analyzed in this study. According to the modeling results, the cutting force has a comparable pattern to the FEA results. The stress contour result confirms that the 2D-VAC method has lower stress than that in the TC method during tool retraction mode. Additionally, the plastic strain in the 2D-VAC method can be higher than that in the TC method. According to the temperature results, the peak temperature in the 2D-VAC could be higher than that in the TC method. The residual stress shows that there is a compressive effect. Thus, the compressive stress is higher than that in the TC method. Micro-hardness results confirmed that there is not too much change from the original surface in the 2D-VAC method. The result of micro-structure morphology also confirmed that there is a significant shear deformation flow in case of the TC method, although less occurs in the 2D-VAC method.

A SOLUTION TO STABILIZE THE RECEIVER BEAMWIDTH WHEN CHANGING THE OPERATING FREQUENCY OF HIGH-FREQUENCY SURFACE WAVE RADAR

2021 ◽  
pp. 2614-2624
Author(s):  
H. H. Dung, C. V. Linh
Keyword(s):  
Signal Processing ◽  
Surface Wave ◽  
Frequency Modulation ◽  
High Frequency ◽  
Operating Frequency ◽  
Design Solution ◽  
Processing Quality ◽  
Wave Radar ◽  
Single Station ◽  
Interference Frequency

A single-station High-Frequency Surface Wave Radar (HFSRR) consists of transmitting and receiving antennas in an area with a distance between them approximately ten times their wavelength. At the coast, these antennas are usually deployed at fixed optimal distances for an operating frequency in the HF band (3÷30Mhz). Because the signal used is linear frequency modulation (FMCW), the HFSWS always requires an interference-resistant frequency band. So, it is necessary to change the operating frequency in HFSWR to avoid strong interference, frequency bands. This also results in a change in the received waveform, which affects signal processing quality. In this article, a design solution is proposed to maintain a consistent beamwidth when changing the operating frequency in the HFSWS.

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