Demonstration of the frequency modulation of optical signals with a high frequency deviation parameter

2008 ◽  
Vol 38 (3) ◽  
pp. 273-275 ◽  
Author(s):  
A V Shamray ◽  
A S Kozlov ◽  
I V Il'ichev ◽  
M P Petrov
2003 ◽  
Author(s):  
Edeltraud Gehrig ◽  
Nicoletta Gaciu ◽  
Markus Pessa ◽  
Ortwin G. Hess

2014 ◽  
Vol 35 (1) ◽  
pp. 36-38 ◽  
Author(s):  
Shang-Fu Chen ◽  
He-Long Syu ◽  
Chi-Chen Huang ◽  
Yueh-Lin Lee ◽  
Chong-Long Ho ◽  
...  

2021 ◽  
Author(s):  
Rendi Kurniawan ◽  
Farooq Ahmed ◽  
Gun Chul Park ◽  
Tae Jo Ko

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.


2021 ◽  
pp. 2614-2624
Author(s):  
H. H. Dung, C. V. Linh

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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