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Reza Khodadadi, Parviz Amiri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 6, November- December 2012, pp.214-224 Designing Optical Beam Filter And Detector Based On Photonic Crystals Structure By FMCW method Reza Khodadadi *, Parviz Amiri ** *(Department of Electrical Engineering, Ahar Branch, Islamic Azad University, Ahar, Iran.)** (Electrical and Computer engineering Department,Shahid Rajaee Teacher Training University,Tehran ,Iran.)ABSTRACT In this study designing and simulation oflaser range finder has been studied by FMCW other hand ,applying laser, one after another, is notmethod that a set based on one-dimensional possible and because of recognizing beamphotonic crystals structure as mid-pass filter and reflector from far distances, laser with relativelybeam detector has been replaces and designed. high power is needed ; so in this conditionThe material of Silicon (Si) and Germanium (Ge) parameters such as cost , dimension and heathas been considered and gained by transfer stability of system are introduced [5, 6]. Usingmatrix method (TMM) of light detector with too high power laser with wave repeat or wavenarrow band width, about 5 nanometers. Also by continuity is impossible and one of the reasonsusing of defect effect and apodization of for measuring distances that are more than onerefraction coefficient profile, wave length bound kilometer by laser pulse transmission is theof optical detector from(630 nm – 645 nm) amount of transmitted beam power.becomes controllable. So measuring ranges is bychoosing transmitter`s laser type and it dependson the wave length of transmitted beam andproportionate to it, error percentage of system isdecreased.Keywords - Range finder, FrequencyModulation of Continuous Wave (FMCW) ,detector , photonic crystalsI. INTRODUCTION Since there are different technics in Fig. 1. One sample of diagram block of distancemeasuring distances as time of flight measuring system(TOF),frequency modulation of continuous wave(FMCW) and phase change , it is possible to According to FMCW method structure ,measure in each condition by continuous spectrum commuting time of conversion is differentiated toof signal or pulse transmission [3,4]. In this frequency and by this way measuring becomes easyresearch, we will study distance measuring by for short and average distances.Therefore in thisfrequency modulation of continuous wave (FMCW). process, laser in continuous state of CW is used andAs we know , using the technics of continuous mentioned state is useable in law powers , so aswave (CW) or laser, one after another , is applied mentioned before, it`s applicable for law distancesfor average distances [1, 3, 4]. Diagram block of [4, 5, 6]. Since the amount of measuring error anddistance measuring system by modulation of accuracy of system is considered in this condition,continuous wave has been shown in figure (1). On for receiving the transmitted beam we shouldthe other hand, applying laser,one after another, is provide condition in a way that can detectnot possible and because of recognizing beam transmitted beam. Also since we have somereflector from far distances , laser with limitations in increasing band width of modulationrelatively high power is needed .So in this wave frequency (linear function of system) [1, 4], ifcondition parameters such as cost , dimension and we limit received and transmitted wave length in aheat stability of system are introduced [5, 6]. special band width by offering a structure basedUsing high power laser with wave repeat or on photonic crystals, we could record the amount ofwave continuity is impossible and one of the distance or measured changes by detecting receivedreasons for measuring distances that are more wave length, Figure (2), [5, 6, 7].than one kilometer by laser pulse transmissionis the amount of transmitted beam power. On the 214 | P a g e
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Reza Khodadadi, Parviz Amiri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 6, November- December 2012, pp.214-224 c.PIR.Fa d (4) 4.F c. f d V (5) 4. f c III. FUNCTION OF FMCW METHOD ANDFig. 2. The block of how beam is received in INTRODUCING STRUCTUREdesigned structure For measuring and comparing minimum and maximum distance, in two following states, weII. FUNCTION OF FMCW METHOD AND study how wave is transmitted and then we consider INTRODUCING STRUCTURE resulted comparisons as follows: In FMCW method, laser power offrequency modulated with sloped surface or sinus a) Triangle and sawtooth wave with fm = 2 KHzwave is done by PRI (Pulse Repetition Interval) b) Triangle and sawtooth wave with fm = 1 KHzalternation period [2, 4]. In this paper transmitted Then after studying each case, quantitativesignal 𝑓𝑒 (𝑡) and received signal 𝑓𝑟 (𝑡) with comparison is done between two states.minimum (fmin) and maximum (fmax) modulationfrequency in band width bound has been called B First state: triangle and sawtooth wavethat received signal after returning from a time with fm = 2 KHzdelay is td that we can observe frequencydifference of beat in both signals as fIF = fe(t) - In this state by exerting modulationfr(t) , Figure (3). signal of triangle and sawtooth wave with PIR = 0.0005 in bound of 4 KHz minimum and 60 KHz maximum , We can study condition by (6) and (7) equations that mentioned signals difference ( Frequency Beat ) is observed in (4) and (5) figures.Fig. 3. Specifications of received andtransmitted signal and their difference In conditions that purpose is assumedfixed , we can measure summation difference andreceived and transmitted frequencies differenceaccording to(1) equation that parameter d is theamount of measured distance and parameter V,purpose speed (movable).In this way, acceptableambiguity bound is CT/2 [4,5,6]. f bu f bd fr (1) 2 f bu f bd fd (2) Fig. 4. Transmitted and received triangle signal 2 with fm = 2 KHz with delay ( above figure ) – c.T . f r two signals difference ( following figure )d (3) 2.B Approximate amount of distancemeasuring is calculated by equation (4) and ifpurpose is no t fixed, by equation (5) speedmeasuring is provided. 215 | P a g e
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Reza Khodadadi, Parviz Amiri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 6, November- December 2012, pp.214-224 Second state: Triangle and sawtooth wave with fm = 1 KHz In this state according to mentioned conditions , by exerting modulation signal of triangle and sawtooth wave with PIR = 0.0001 in bound of 4 KHz minimum and 60 KHz maximum , we can study existed signals difference (Beat Frequency) and observe them in (7) and (8) figures [1, 2, 4].Fig. 5. Transmitted and received sawtooth signalwith fm = 2 KHz with delay ( above figure ) –two signals difference ( following figure) 4.B.d min Fa (min) 4 KHz (6) c.PIR 4.B.d max Fa (max) 60KHz (7) c.PIR So we can study the results of minimumand maximum measuring amounts of distances Fig. 7. Transmitted and received triangle signalfrom 2m to 30m have been considered in with fm =1 KHz with delay ( above figure ) –figure (6) for both triangle and sawtooth wave two signals difference ( following figure)in a condition that PIR = 0.0005 and observedone calculations. Fig. 8. Transmitted and received sawtooth signal with fm = 1 KHz with delay ( aboveFig. 6.Minimum and maximum distance with figure ) – two signals difference ( followingPIR=0.0005 of triangle wave ( above figure ) figure )– sawtooth wave ( following figure ) 216 | P a g e
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Reza Khodadadi, Parviz Amiri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 6, November- December 2012, pp.214-224By observing distance amounts change in figure wave figure of received and transmitted(9), we can see increase in distance measure from mixed signal with modulation wave frequencyminimum amount of 4m to maximum amount of fm = 2 KHz and analyze simulation results toof 60m and consider gained results with PIR= observe input beam to considered mid-pass0.001 and compare with figure (6). filter.Fig. 9.Minimum and maximum distance withPIR= 0.001 of triangle wave ( above figure ) – Fig. 10. Wave figure of mixed signal in two sawtooth wave ( following figure ) states ( triangle – sawtooth ) with modulationTherefore we can conclude that one of the frequency of 2 KHzmethods of increasing measure of maximumand minimum amounts is distance bound of Since in distance measuring of systemfrequency decreaseof fm modulation wave that structure, APD is used to detect received andenforcing this condition has limitation and transmitted mixed signal [3, 4], in this conditionbecause of having linear function , we can`t by applying a mid-pass filter design consideredincrease PIR more than limit amount [6] . So as band width and to measure distance ,exert outputwe observe in figure (9) , to increase distance final signal to one microcontroller(AVR). So inmeasure bound from minimum amount of this study , first we offer performed design in4m to maximum amount of 60m, conditions circuit level and then explain the structure ofare provided in a way that by exerting triangle suggested optical defector by photonic crystals.or sawtooth wave with 1 KHz alternationperiod , we can gain considered results. So IV. DESIGNING IN CIRCUIT LEVELaccording to identical conditions of minimum According to the block diagram ofand maximum modulation frequency in each figure (1) in this design , circuit in figure (11) hastwo triangle and sawtooth signal ,we can been used as VCO unit for making 2 KHz triangleconclude that by increasing the amount of wave oscillator in controllable bound with 3 voltalternation period of modulation signal ( PIR minimum and 7 volt maximum.), measureable distance is increased and in fact , VCC 1according to equation (8) this condition has R2 R3reverse relation with frequency modulation ofconsidered wave ( triangle or sawtooth wave) [5, U1 LM311 510]. 0 R1 8 R4 2 V+ 6 B + B/S 1T PIR d (8) Vi V1 = 0 OUT 7 Out 1 fm V2 = 5 PW = 0.25ms 3 - 4 G 1 PER = 0.5ms V- Now according to the function of 0system against PIR changes , we study -VCC 1 217 | P a g e
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Reza Khodadadi, Parviz Amiri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 6, November- December 2012, pp.214-224 C1 Therefore existing equations of this circuit are R6 studied and analyzed as follows: U2 -VCC2 VCC1 LM318 V (U1) ,V (U1) Vin (9) 4 5 R5 2 2 V- C3Out 1 - 8 VCC1 if Vin Vo (U1) VCC1 C2 6 OUT Out 2 (10) 3 + 7 C1 1 2 V+ VCC1 if Vin Vo (U1) V1 (U1) VCC1 (11) R7 2 R8 VCC 2 2 (Vm ax Vm in )VCC1 0 SignalRamp TrFig.11. Triangle wave producer circuits with 2 42 KHz frequency 16000 v (12) 0.5 10 3 s Working procedure of above circuit is atthis way: first we should produce one slopesignal for frequency modulation, in this design, we R have used comparator ICs of LM311 model for Vo ( dc ) (U 2) V 1 6 Vdc ( Ramp) 5 (13) R producing TTL square pulse and complex circuit 5 of LM318 model for making triangle waveproducer. 1 RC So it`s necessary to regulate voltage level Vo ( dc ) (U 2) Vi (t )dtof this pulse in a way that necessary slopes for VCC1 VCC1triangle wave would be accessible, by changing 16000 R5 .C1 (14)suggested volume of R7 in sample design , we R5 .C1 16000can change the amount of output offset level andcontrol it. Also resistance amount of R6 variableis chosen so big that by increase in fixed time According to mentioned materials , invalue of integration system , smooth triangle transmitting continuous wave modulation signalwave is made (or by choosing C2 variable we can study the difference between simulationscondenser , we can increase capacity amount ). of range finder with two different states and compare the difference between these two states of MC1648 complex circuit. D1 C3 MV1404 Out 1 L1 0.68uH 0 D2 U3 FM out MV1404 10 3 12 BPT OUT TANK C2 5 AGC 1 R9 14 VCC1 Vcc1 7 VCC2 C4 C5 VEE 0.1uF MC1648 0 Fig. 13. VCO oscillator circuit by using of MC1648 Down complex circuit is a voltage controllable oscillator (VCO) in linear function bound of 55Fig. 12. Input - output pulse simulation signals , MHz to 130 MHz.out1 and out2 of circuit of figure (11) 218 | P a g e
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Reza Khodadadi, Parviz Amiri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 6, November- December 2012, pp.214-224 2VCC1 2V BE I C (Q3) hfe (Q 6). I PIN (17) R10 I C (Q3) VCC1 VBE hfe (Q6). I PIN I LD (18) 2 RC1 2 VFM ( R hie(Q1) 2 E 0.4 RE V mA (19) I LD 1 hfe 7Fig. 14. Output signal of VCO oscillator According to above conditions , we canmake the driver of transmitted beam bystimulation of MC1648 complex circuit. Soaccording to complex circuit data sheet,we selectcircuit elements proportionate to designingmethod to have QL>100 maximum. 1 f min (15) 2 L(C D (max) C S ) Now according to mentioned conditionsand oscillator signal production , we exert Fig. 15. SLD1132VS laser driver circuitresulted output to a laser driver circuit . Appliedlaser diode of this design is SLD1132VSthat in wave length bound is minimum 625nm to maximum 645 nm that in normalcondition and in normal temperature has 635nm wave length with output power of Po = 3mW. In this level ,through driver circuit offigure (15) ,wave length is transmitted bychoosing laser transmitter that in this paper, SLD1132VS laser diode with normal wavelength of 635 nm has been used fordesigning simulation part.As we know , oscillationextent for modulation of laser current isconsidered 10% of the amount of fixedcurrent [6]. So laser current oscillates as 7 mA around 60mA. In offered driver circuit we have used adifferentiated reinforcement to control current byAPC circuit , the duty of APC circuit isconverting diode current to control current. Socircuit form and related equations of laser diode Fig. 16. Characteristic of simulated laser driverfunction are as follows. circuit gain I B (Q6) I PIN (16) RE resistances have been added to increase the bound of circuit linear function that for large 219 | P a g e
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Reza Khodadadi, Parviz Amiri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 6, November- December 2012, pp.214-224 amounts of 2RE.IRE , in comparison with VT linear bound it continues till this amount: 2RE .I RE VFM (20) In this level by using of APD detector through receiving reflected beam , detection is done according to figure (1) block and then in acceptable band In this level by using of APD detector through receiving reflected beam, detection is done according to figure(1) block and then in acceptable band width of 30 KHz , according to figure (17) circuit, designed mid-pass filter is controlled.Since APD Fig. 18. Gain bound of mid- pass filter output detector output signal is a mixed frequency harmonics that should pass through a filter to gain differentiated signal. For eliminating dc Now we turn to offer a suggested surface of mixer output signal , according to structure of continuous photonic crystals of following figure we can use a third rank up- pass Germanium and Silicon and according to filter. offered explanations on detection, we study and simulate the conditions of this design and R21 new function of structure through APD [8, 9]. VCC2 VCC2 In fact, the purpose of this paper is to offer an optical detector based on photonic R18 R20 LM318 4 5 V- C3 crystals that has a combination of received 2R17 - 8 R22 R23 R24 beam and mid- pass filter block in wave C2 R19 OUT 6 length bound ( 625 nm – 645 nm ) jointly , 3 1 -VCC2 + 7 C1 C13 C14 C15 therefore we explain the characteristics of V+ 0 U3 simulated filter completely. C10 C11 C12 -VCC2 0 0 0 V. OPTICAL FILTER AND DETECTORMix Out APD DESIGNING R14 R15 R16 According to the general structure of optical receivers, that has been shown in figure 0 0 0 (19) by considering all introduced noise resources , we have used defect exerting technic to periodic network to study applied Fig. 17. Characteristic of simulated laser driver filter and detector results [2, 9]. So by using of circuit gain transfer matrix method or TMM we study the response of considered filter frequency in wave length bound with (625 nm – 645 nm) band width. According to this condition, we have used an up- pass filter with high resistance amount in mixer output. Then it has been used an OP_Amp for buffering and correcting dc surface. So this RL Ra Amp condition leads to the separation of two down- jamp idet Cd it irs Ca pass and up- pass filters and omits loading effect on each other. Now after buffering, again it has used a third rank down- pass filter that eliminates Fig. 19. Characteristic General structure of optical existed high signals of spectrum. At this way,the receivers output of filter is differentiated signal that should be reinforced. Mid-pass filter has 3 KHz < PB < 60 According to the effect of reinforcing input KHZ passing band. layer that contains (jamp current source, Ca capacitor and Ra resistance), in circuit of optical receivers (APD), we should consider quantum noise (irs) and thermal noise (it) in circuits and compare optical detector capacitor (Cd) and received optical detector 220 | P a g e
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Reza Khodadadi, Parviz Amiri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 6, November- December 2012, pp.214-224 current (idet) proportionate to RL load resistance.In this structure, we have used 203 layers k lx nl cos l , l 0,1,2,...,N , S l (25) symmetrically from left to right first and last layers c have been had Silicon and Germanium crystal with d l xl xl 1 , l 0,1,2,3,..., N (26) nSi= 3.45 and n Ge= 4 refraction coefficients , figure (20). So by identifying the amounts of electric field matrix and A0 , B0 , 𝐴 𝑠 , 𝐵 𝑠 coefficients as first and last layer , we can observe and conclude transmission and reflection diagrams of signal. A0 AS Fig. 20. 203- layer structure with air distance and M (27) apodization effect of refraction coefficient profile B0 BS 2 n cos s 1 In order to exert defect in mid layer, we T s (28) have used air distance with n air= 1 refraction n0 cos 0 m11 coefficient ( air distance has been considered in 102th layer ) and apodization effect of refraction coefficient profile in optical filter Since 𝜽 𝟎 = 𝟎 is input wave angle in first layer, behavior.Therefore in second to 101th layers , 𝜽 𝒔 = 𝟎, input wave angle in last layer, n 0 , from left to right respectfully with 0.015 steps, refraction coefficient of first layer and n s refraction coefficients are decreased till refraction of last layer , so band width amount of 102th layer with 1 refraction coefficient. designed optical detector is measured and So from 103th layer to 202th layer , analyzed by equation (29). refraction coefficient is a dded with 0.015 2 steps conversely till finally in 203th layer Si and n 1 Ge crystal are used, so the total number of all T s (29) layers is 203 layers . Also in this suggested n0 m11 sample, we use apodization method of refraction coefficient profile (Graded Index) to get desired Gained results of optical detector band width [2, 8]. simulation are observed and studied in (21) and (22) figures. In this state we can receive VI. EQUATIONS AND SIMULATION RESULTS transmitted beam in wave length band width Performed simulation results are based bound of 630 nm to 645 nm and make on identical layers width (dl=10 nm) and distance measurement conditions possible by numerical modeling and have been used using of an optical converter to digital signal. transfer matrix method (TMM) . So conditions in TE mode and mathematical equations are studied as follows: M 11 M 12 N M D01 Dl Pl Dl1 DS (21) M 21 M 22 i 1 1 1 Dl nl cos l (22) nl cos l In this state , band width amounts are calculated through the calculation of D dynamic matrix and P spreading matrix in boundary conditions and TE mode by supposing 𝜃 𝑙 as input wave angle and dl as identical distance between two consecutive layers. e il 0 Pl il (23) 0 e (a) l k lx d (24) 221 | P a g e
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Reza Khodadadi, Parviz Amiri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 6, November- December 2012, pp.214-224 (b)Fig. 21. Characteristic of optical detectoroutput by using of apodization method ofrefraction coefficient profile – (a) transmission ,(b) reflection Fig. 23. Frequency response change of structure by the effect of layers width increase in identical amount (dL1= dL2= 30 nm) In this level , in order to observe the function of passing beam from offered structure output and detector , we should suppose that mixed beam of figure (10) has been exerted to the suggested structure, in this way we analyze the output of designed detector , gained results are observed in figure (24).Fig. 22. Characteristic of optical detector outputgain in terms of wave length(above figure) –interms of frequency (following figure) Now if there is change in layers width,there will be disorder in structure detectorreceiving bound. In order to prove this claim ifwe increase the width of layers(dl= 30) identically Fig. 24. Received beam figure of crystal detector, we will have frequency shift and beam So by receiving beam in designed structure bound ,receiving bound plurality and will not have beam we can control system operation in this wavereceiving in 636 nm wave length or 473 GHz length and perform distance pulses count throughcentral frequency , suitably,so signal detector wave exertion to an optical beam convertor to electriclength is out of our design and it`s not signal.acceptable,figure (23). 222 | P a g e
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Reza Khodadadi, Parviz Amiri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 6, November- December 2012, pp.214-224VII. COMPARISON OF APD OF S3884 directly, so transmitted wave length will have MODEL BY DESIGNED PHOTONIC identical beam receiving bound. CRYSTAL STRUCTURE According to the characteristics of APD REFRENCESoptical receiver data sheet and offered third [1] Toshiya Mitomo ,Member, IEEE , Naokorank mid- pass filter in this design , received Ono, Hiroaki Hoshino , Yoshiakiwave length in maximum peak is 800 Yoshihara, Member , IEEE ,Osamunanometers. Since the wave length of selected Watanabe, Member , IEEE, and Ichirolaser receiver is 635 nanometers in peak Seto , Member , IEEE “A 77 GHz 90 nmamount , designed detector has been predicted in CMOS Transceiver for FMCW Radara way that has been set in nearest bound to Applications ” , IEEE JOURNAL OFlaser transmitter wave length . Some differences SOLID-STATE CIRCUITS, VOL. 45,of this detector with designed one dimensional NO. 4, APRIL (2010).photonic crystal structure are studied and [2] Jian-Bo Chen , Yan Shen , Wei-Xiobserved in following table. Zhou , Yu-Xiang Zheng, HaiBin ZhaoTable 1. The difference between a photonic and Liang-Yao Chen “Comparisoncrystal structure detector model Study of the Band-gap Structure of aType of Photonic APD 1D - Photonic Crystal by Using TMMdetector crystals (S3884) and FDTD Analyses”, Journal Of theSpectral Korean Physicalresponse 630 to 645 400 to 1000 Society,Vol.58,No.4,April(2011)range 𝞴 (nm) [3] Eugin Hyun , and Jong-Hun Lee “ Method to Improve Range and VelocityCut-Off 473 (Thz) 400 (Mhz) Error Using Deinterle-aving andfrequency ( fc ) Frequency Interpolation forPeak sensitivity Automotive FMCW Radars”,wavelength International Journal of Signal 636 800 Processing , Image Processing and Pattern 𝞴p (nm) Recognition Vol. 2, No. 2, June (2009).Type Filter Method TMM Circuit [4] Shahram Mohammad Nejad,Saeed OlyaeeDetector 4.724 THz 3 KHz “Comparison of TOF, FMCW and Phase-bandwidth < PB < < PB < Shift Laser Range Finding Methods byfilter 4.745 THz 60 KHz Simulation and Measurement”, Quartarly Journal of Technology & Education VolType of .1 , No.1 Autumn (2006). Laser LaserTransmitter [5] D. Dupuy, M . Lescure, M. Cousineau, “A FMCW Laser Range-Finder Based onVIII. CONCLUSION a Delay Line Technique ” , IEEE In this study designing method of one Instrumentation and Measurementoptical beam filter and detector sample has been Technology Conference Budapest ,studied in wave length bound of 630 nm to 645 Hungary, May 21-23, (2001).nm based on Germanium and Silicon photonic [6] Mohammad Nejad S. and Mirsaeedi H.crystals structure. As it was observed , to measure , “ Altitude measurement using laserlonger distances by FMCW method , we should beam reflected from water surface”,decrease the band width amount of continuous International Journal of Engineeringmodulation wave or have the maximum Science ,Vol. 1, No.1, (2005).amount of measurement by PIR increase. [7] Leonhard Reindl , Member , IEEE , Since there is limitation in B decrease or Clemens C. W. Ruppel, Senior Member ,increase in alternation period of wave , that `s IEEE, Stefan Berek, Ulrich Knauer ,enough to provide condition in a way that Associate Member , IEEE , Martintransmitted beam is created in special wave Vossiek, Member, IEEE, Patric Heide,length to perform detection in considered bound Senior Member , IEEE, and Lutz Oréansin opposite point and finally measure unknown ,“Design,Fabrication, and Applicationdistance through optical convertors to digital of Precise SAW Delay Lines Used inones. So we can receive desirable result and an FMCW Radar System ” , IEEEmaximum operation of received beam in TRANSACTION Sn ONmaximum 473 GHz frequency proportionate to MICROWAVE THEORY AND636 nm designed wavelength maximum. Also we TECHNIQUES, VOL. 49, NO.4, APRILcan use this detector in a condition which it has (2001).been set in front of optical beam transmitter 223 | P a g e
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Reza Khodadadi, Parviz Amiri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 6, November- December 2012, pp.214-224 [8] Lu Xiaodong , Han Peide, Quan Yujun ,Ran Qijiang, Gao Lipeng , Zeng Fanping , Zhao Chunhua , Yu Jinzhong “Optical response of high-order band gap in onedimensional photonic crystal applying in-plane integration ” , Optics Communications 277 (2007). [9] Safwat W. Z. Mahmoud, Moustafa F. Ahmed and M. A.Kaid “ Synthesis of Multilayer and Waveguide Filters for use in Optical Communication Systems”, Egypt. J. Solids, Vol. (28), No. (1), (2005). [10] Peter K.C.Chan,W.Jin,Senior Member,IEEE,J.M.Gong and M. S.Demokan, Senior Member , IEEE “ Multip- lexing of Fiber Bragg Grating Sensors Using an FMCW Technique”,IEEE PHOTONICS Technolo Yletters,Vol.11,No.11,November(1999).Authors’ information Reza Khodadadi was born in Tehran , Iran, in 1975.He received the B.Sc. and M.Sc degrees in electrical engineering , electronics , Islamic Azad University , Karaj branch , Karaj , Iran and Islamic Azad University , Ahar, Iran , in 2000 and 2012 , respectively. Hisresearch interests include Strength- ening theOptical Sensors, Photonic Crystals, Laser,WirelessNetworks, LNA,Audio Mixers ,RF Application ,Signal Processing and Artificial Intelligence. Mr.khodadadi is a lecturer in Islamic AzadUniversity, Karaj Branch, Karaj, Iran. Parviz Amiri Received B.S degree in electrical engineering from University of Mazandaran in 1994 and M.S Degree in electrical engineering From Khajeh NasirToosi(KNTU)University in 1997, and PHD degree in electricalengineering from Tarbiat Modaress university in2009 Tehran, Iran, He is currently research inelectronic circuit designing in industries anduniversity. His primary research interest is in RFand power electronic circuits, with focus on highefficient and high linear power circuit design. He iscurrently with the Department of ElectricalEngineering at Shahid Rajaee teacher trainingUniversity in Tehran, Iran. 224 | P a g e
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