Implementation of types of VCO

Author(s):  
Akshata O. Kattimani

Abstract: A Voltage Controlled Divider (VCO) is a basic building block in most of the electronic systems. Phase-locked loop (PLL), tone synthesizers, Frequency Shift Keying (FSK), frequency synthesizers, etc make use of VCO’s to generate an oscillating frequency that can be decided with the help of components. Voltage Controlled Divider can be implemented for analog applications. The project proposes three types of VCO using Electric tool and LT Spice XVII tool. The three VCO’s that are implemented are CMOS Ring Oscillator, Colpitts Oscillator and Relaxation Oscillator. These circuits generate two oscillating frequencies that is decided by the circult components. Keywords: Voltage Controlled Divider (VCO), CMOS Ring Oscillator, Colpitts Oscillator, Relaxation Oscillator, oscillating frequency.

Author(s):  
Suryo Novantara ◽  
Heroe Wijanto ◽  
Basuki Rahmat

Dengan ditertibkannya frekuensi siaran FM (Frequency Modulation) dalam spasi kanal 200 kHz, maka suatu sinyal siaran FM stereo yang hanya memerlukan lebar-pita frekuensi 112 kHz (2 ? 56 kHz multipleks pita-dasar FM stereo termodulasi secara narrow band FM) akan memberikan ruang spektral sisa selebar sekitar 94 kHz pada setiap spasi kanal. Penyisipan informasi lain pada ruang sisa spasi kanal tersebut biasa disebut SCA (Subsidiary Communication Authorization), yang bertujuan untuk meningkatkan efisiensi penggunaan alokasi spektral FM. Penelitian ini mengusulkan penyisipan informasi berupa sinyal Data Text digital termodulasi FSK (Frequency Shift Keying) sebagai fasilitas siaran tambahan. Informasi Data-Text diperoleh dari deretan kode biner serial berkecepatan 1200 bps yang dibangkitkan dari port RS-232 komputer. Sinyal FSK Data-Text tersebut dimodulasikan ke subcarrier 67 KHz untuk selanjutnya digabungkan dengan sinyalsinyal multipleks audio stereo. Seluruh sinyal komposit dipancarkan dalam modulasi narrow-band FM dengan frekuensi carrier sesuai alokasi siaran FM 88 � 108 MHz. Sinyal tambahan ini perlu dijaga agar tidak terjadi tumpang-tindih spektral dengan sinyal matriks audio stereo melalui BPF (Band Pass Filter) pada frekuensi tengah 67 kHz dan bandwith 13,4 kHz. Untuk proses demodulasi sinyal FSK-Data-Text SCA dapat digunakan rangkaian PLL (Phase-Locked Loop). Untuk tampilan Data-Text digunakan LCD.Kata kunci : SCA, multipleks audio stereo, FSK-Data-Text, narrow band FM, LCD


2012 ◽  
Vol 532-533 ◽  
pp. 827-831
Author(s):  
Jiang Hua Xia ◽  
Jing Guo ◽  
Xiao Ming Wang

The Frequency-Shift Keying (FSK) signal is frequently used in track circuits because of the strong ability of resistance interference. Symbol rate is one of the important signal parameters for safety of railway. The paper propose a algorithm of high precise detectation of FSK signal using Chirp-Z transform; Theoretically gives the detailed explanation to the major technique, and has carried on the Matlab simulation, The simulation result indicates this method during the enhancement is shifted signal examination precision, reduced the computation order of complexity.


1982 ◽  
Vol 30 (5) ◽  
pp. 1048-1051 ◽  
Author(s):  
R. LaRosa ◽  
T. Marynowski ◽  
K. Henrich

Sensors ◽  
2015 ◽  
Vol 15 (8) ◽  
pp. 18641-18665 ◽  
Author(s):  
Laurent Segers ◽  
David Van Bavegem ◽  
Sam De Winne ◽  
An Braeken ◽  
Abdellah Touhafi ◽  
...  

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