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Article
Study of temperature- dependent modulated VCSEL dynamics
دراسة لحركيات ليزر شبه الموصل ذي التجويف الشاقولي والباعثة للضوء سطحيا المضمن والمعتمد على درجة الحرارة

Author: H. A. Sultan حسن عبدالله سلطان
Journal: Journal of Basrah Researches (Sciences) مجلة ابحاث البصرة ( العلميات) ISSN: 18172695 Year: 2011 Volume: 37 Issue: 4A Pages: 38-43
Publisher: Basrah University جامعة البصرة

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Abstract

In this work the nonlinear dynamics of Vertical Cavity Surface Emitting Laser (VCSEL) is studied. The rate equations describing VCSEL dynamics are solved numerically. The simulation shows that the directly modulated VCSEL output power and its modulation response are sensitive to the injection current, the modulation signal amplitude and frequency. The study proves that VCSEL dynamics is strongly affected by the variation of temperature.

درس في هذا العمل الحركيات اللاخطية لليزر شبه الموصل ذي التجويف الشاقولي والباعثة للضوء سطحيا. تم حل معادلات الحركة التي تصف هذا الليزر عدديا. أظهرت المحاكاة أن قدرة خرج الليزر المضمن وكذلك استجابته للتضمين تكون حساسة لتيار الحقن, سعة أشارة التضمين والتردد المضمن. أثبتت الدراسة أن حركيا ت هذا الليزر تتأثر بشدة عند تغيير درجة الحرارة.


Article
Design and Implementation of Frequency Modulation Continuous Wave Radar for Adaptive Cruise Control Interfaces with PIC Microcontroller

Authors: Dr. Manal H. Jassim1 --- Tamara Z. Fadhil2
Journal: IRAQI JOURNAL OF COMPUTERS,COMMUNICATION AND CONTROL & SYSTEMS ENGINEERING المجلة العراقية لهندسة الحاسبات والاتصالات والسيطرة والنظم ISSN: 18119212 Year: 2016 Volume: 16 Issue: 1 Pages: 92-103
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Abstract –This paper, presents the design and implementation of Frequency Modulation Continuous Wave (FMCW) radar system working at 77GHz for Adaptive Cruise Control (ACC) technology which is a flexible system to estimate the speed and distance in accordance to vehicle ahead, which reduces the forces on the rate of accidents by warning the driver when two vehicles become too close. In addition, the principle of FMCW radar is presented to generate Linear Frequency Modulated Continuous Wave (LFMCW) sweep waveform through frequency bands with triangular frequency modulation using Voltage Control Oscillator (VCO), a triangle sweep pattern adopt will resolve ambiguity without Doppler processing. This improves the decision making before hardware implementation. The simulation design is achieving the desired performance, one parameter warrants further attention. In the FMCW configuration, the sweep time is about 25 microseconds. Therefore, the system needs to sweep a 140 MHz band within a very short period. Such an automotive radar may able to meet the cost requirement.

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