BRIGHT SOLITON GENERATION USING P-CHANNEL MOSFET. Thanjavur,Tamilnadu, India.

Transcription

1 Volume 119 No , ISSN: (on-line version) url: BRIGHT SOLITON GENERATION USING P-CHANNEL MOSFET 1 M.Easwaran, 2 Dr.R.Ganapathy 1 Department of ECE, School of EEE, SASTRA Deemed University, Thanjavur,Tamilnadu, India 2 Department of ECE, School of EEE, SASTRA Deemed University, Thanjavur,Tamilnadu, India 2 rganapathy@ece.sastra.edu Abstract: A periodic train of short duration pulses are used in number of applications such as high speed sampling, wide band radars and RF high power generation. Solitons are a special type of pulse, dumbbell shaped waves that propagate without changing their wave shape in a medium. A balancing mechanism between non linearity and dispersion (linearity) is responsible for the soliton phenomena. In this paper, we have presented a very simple method to generate a train of pulse (bright solitons) using the inherent parameters of the p-channel MOSFET. Keywords: Soliton, Bright Soliton, Dark Soliton, NLTL 1. Introduction: An electrical bright soliton pulse is characterized by its ability of maintaining its size and shape unaltered during the propagation through a given medium.the electrical soliton can be generated by balancing the linear effects and nonlinear effects [4,5,6]. Extensive research work has been carried out in the generation of electrical bright and dark soliton pulses as they help in the understanding of the concept and the nature of complex nonlinear system [1,2,3]. Soliton based communication systems are more efficient with less noise than square pulse. Soliton based carriers are most suitable for ASK,FSK transmission rather than square pulse[4,5]. Two different types of soliton oscillator have been developed. In 2007,D.Ricketts developed Electrical soliton oscillator and On the self-generation of electrical soliton pulses. It comprises CMOS amplifier circuit,feedback through NLTL with adaptive bias control. NLTL having the parallel combination of inductor and variable 2785

2 capacitor(varactor).when exact balancing takes place between linearity and nonlinearity,soliton pulses are generated. Another type of Reflection Soliton Oscillator developed by D.Ricketts and Donhee Ham in 2009.This oscillator consist of a nonlinear transmission line(nltl).one side of it which is connected to one port amplifies and the other side is open. After steady state a selfgenerated short duration pulses travels back and forth on the NLTL,reflected at both ends due to impedance mismatching. In this paper we are very simply generating the soliton pulses by utilizing the inherent parameters of the MOSFET.When the continuous (sinusoidal) signal is applied on the nonlinear region of the P-MOSFET transfer curve,the input signal split into different frequency component i.e., the pulses are generated. Normally NLTL is madeup of parallel combination of inductor and capacitor.inductor will provide linear effect and capacitance will provide non- linear effect [10,11].Bright soliton pulses arises when there is perfect balancing between the linear and non- linear effects [8,12].When the continuous signal (sinusoidal) is applied as Vgs is slightly greater than Vgs threshold (in nonlinear region or moderate inversion region) the pulse will be obtained. For an appropriate value of voltage Vgs,perfect balancing takes place between dispersion and nonlinearity.due to this effect sharp pulses are generated,taking FFT of this narrow pulse amplitude of the harmonics are exponentially decreased [16-19]. If it is operated in nonlinear region but dispersion and nonlinearity are not exactly balancing means we get somewhat wider pulse (not narrow), more number of harmonics are present.[20] Fig.1.Transfer curve of P- MOSFET 2786

3 Fig.2. Equivalent circuit of P channel MOSFET. Fig(1) shows the transfer curve of P MOSFET slightly greater than Vgs threshold(moderate inversion region-highlighted in the curve) the channel will be created between gate and source, that is given as Fig(2) Equivalent circuit of P- channel MOSFET. Fig.3. RC equivalent circuit Fig.4. L-C equivalent circuit Fig(3) RC equivalent circuit of the channel given. Normally delayed periodical arrangement of resistor provides the effectof inductance, so the channel equivalent circuit will become L-C combination[13,14] given in Fig(4) shows L-C equivalent circuit of the P-channel.ie nonlinear transmission line(nltl). For a particular value of the applied input sinusoidal signal balancing between the dispersion and nonlinearity takes place and solitons pulses are generated. 2787

4 2. Materials &Methods VDD 9V R1 1kΩ 2 output 1 q1 0 V1 0 Fig 5(a) Circuit Diagram Fig 5(b) PCB for the Circuit Fig.5.c the channel is created. (starts conduction) Fig.6a.Soliton Pulse Fig. 6(b) FFT of Soliton 2788

5 Fig 7a. Pulse Fig 7b.FFT of the Pulse Fig 8a.Wider Pulse Fig 8b.FFT of Wider Pulse 3. Results & Discussion Some properties of soliton pulses are proved experimentally. When a continuous input signal (Sinusoidal waveform) is applied into a nonlinear region of MOSFET characteristics it will split into different pulses. This is the basic principle of generating soliton pulses and obtained it experimentally. Another principle is collision of pulses, i.e. suppose two different pulses with different frequency travels ina same channel the two signals are collide and after that both are travelling in the same channel without changing their wave shape,i.e. the wave shape will be preserved after the collision takes place. During the collision both signals are in phase the amplitude increases and rest of the time it travels as such a way, this is applicable for soliton pulses only. Here we have tested for three different cases. First we used square pulses, snapshot given for each case first one shows Fig 9 (a) 2789

6 Fig 9 (a) Two square pulses travel at different frequency and different channels Fig 9 (b) Both are travelling in same channel two different square pulses with different frequency travels in different channels. Fig 9 (b) shows the collision of two square pulses and the original signal cannot retraced (both are combined). For second case we used a narrow pulse with two different pulses with different frequency travelling in different channel shown in Fig 10. Fig. 10(a) Two different pulses travelling at different frequency and channels. Fig. 10(b) FFT of the Pulse Fig. 10(c)Collision takes place Fig. 10(d) After the collision two waveforms are settled (amplitude of the pulses are varied) 2790

7 In Fig 10 (a) (c) (d) shows the collision, after the collision the two signals are retracedone with same amplitude and another signal amplitude is very much reduced. For third case considering two solitons with different frequency travelling in same channel shown in Fig 11 (a). Fig. 11(a) Two waveforms are close each Other for collision Fig. 11(b) Collision takes place and both are in phase the amplitude is increased Fig. 11(c) After the collision the two signals Fig. 11(d) After the collision the two signals are retrieved Are travelling in the same channel without changing their waveshape In Fig 11 (b) (c) (d) shows the collision of solitons, both are in same phase the amplitude increases and both signals are retraced without changing their wave shape[15]. The wave shape of the soliton pulses looks like a dum bell shape, mathematically it is derived and proved assech(x). In all aspect it is proved the generated pulse as a bright soliton.here the experimental result and simulated waveform are compared and it is shown in figure

8 Fig. 12 Comparison of experimental and simulated results. 4. Conclusion Bright soliton pulses are generated by very simple method using the inherent parameters of P-Channel MOSFET. In the communication applications square wave based carrier signals are affected by the infinite number of harmonics and the pulse shape also changed at high frequency. So, cost effective soliton based carrier signal can be used in the communication application effectively with less error rate. REFERENCES [1] Amiri IS, Alavi SE, Idrus SM. Soliton coding for secured optical communication link. 1 st ed. Singapur: Springer-Verlag;2015. [2] Hirota R. The direct method in soliton theory. 1 st ed. UK: Cambridge university press; [3] Filippov AT. The versatile soliton. 1 st ed. USA: Springer science and business media; [4] Kivshar YS, Agrawal G. Optical solitons: From fibers to photonic crystals. 1 st ed. USA: Academic press; [5] Porsezian K, Ganapathy R, Hasegawa A and Serkin V N. Non autonomus soliton dispersion management. IEEE J Quantum Electron 2009, 45: [6] Ganapathy R. Soliton dispersion management in nonlinear optical fibers. Communications in nonlinear science and numerical simulation 2012; 17: [7] Yildirim OO, Ricketts DS, Ham D. Reflection soliton oscillator.ieee Trans. Microwave Theory and Technique 2009; 57: [8] Li X, Ricketts DS, Ham D. Solitons in electrical networks. McGraw-Hill 2008 yearbook of science and technology;

9 [9] Ricketts DS, Li X, Sun N, Woo K, Ham D. On the self-generation of electrical soliton pulses. IEEE J. Solid- State Circuits 2007; 42: [10] Ham D, Li X, Denenberg S, Lee TH, Ricketts DS, Ordered and chaotic electrical solitons: communication perspectives. IEEE Communications Magazine 2006; 44: [11] Ricketts DS, Ham D. Electrical solitons: theory, design and applications. USA: CRC Press; [12] Remoissenet M. Waves called solitons: Concepts and Experiments. 1 st ed. USA: Springer science and business media; [13] Ytterdal T, Cheng Y, Fjeldly T. Device modeling for analog and RF CMOS circuit design. UK: John Wiley and Sons Ltd; [14]YannisTsividies, Cocin Me Addrew The Mos Transistor 3 rd Edition 2013 Oxford University Press. [15] Ferran Martin Artificial transmission lines for RF and microwave applications, John wiley&sons,2015. [16] Mohanraj.R,Easwaran.M, Vimala.R, Aravind britto.k.r, Certain performance investigations of various pulse triggered, 2018: 119: [17] Easwaran, M. Electrical dark soliton generation using CMOS seven stage ring oscillator with adaptive bias control, Journal of Advanced Research in Dynamical and Control Systems, vol. 9, pp , [18]Easwaran, M., and R. Ganapathy. "DARK SOLITON GENERATION USING CMOS RING OSCILLATOR.", ARPN Journal of Engineering and Applied Sciences, vol. 13,no. 3, pp , Feb [19] Easwaran, M,. "Dark soliton generation using N-Channel MOSFET.", International Journal of Pure and Applied Mathematics, vol. 117, pp , [20]Dr. Divya Midhunchakkaravarthy, An Efficient And Secure Detection Of Internet Worm Using Propagation Model, International Journal Of Innovations In Scientific And Engineering Research, Vol.3, Issue.1, 8-15,

10 2794