Tarush Ganesh ShenoyElectronics and TelecommunicationThakur College of Engineering and Technology,[email protected] Kumaresha AcharyaElectronics and TelecommunicationThakur College of Engineering and Technology,[email protected] JangidElectronics and TelecommunicationThakur College of Engineering and Technology,[email protected] Dr.
VinitkumarDongreElectronics and TelecommunicationThakur College of Engineeringand Technology,[email protected] Abstract—Worldwide, there is anaverage demand of nearly 96 million barrels of oil and liquid fuels per day.
With such high demands of fuel, we cannot afford to have losses. The majorlosses take place when this fuel is stored and the measurements are taken. Thefuel tanks are majorly 40m in height as well as 40m in radius. In such largefuel tanks, even an error of a small millimeter can cause a large loss. Thus itis really important to design a system which is highly accurate in measuringfuel levels.
The current measuring devices available in the market are havingan accuracy of 3mm-10mm. Using FMCW (Frequency Modulated Continuous Wave) RADARat a very high frequency (of 24GHz) is what we aim, so as to lessen the errorup-to 1mm. By doing this we can save up-to 4000$ dollar behind every fuel tank.The system works on the beat frequency concept.
The receiver system is designedfor receiving the beat frequency and processing the received signal to get the fuellevel measurement.Keywords- FMCW, high frequency, 24GHz, LNA, Signalprocessing, quadrature mixer, accuracy, beat frequency, LABview I. IntroductionIn recent times, FMCW (Frequency Modulation ContinuousWave)are being widely used for the measurement of distance/range in a varietyof industrial applications like automotive safety, level gauges, defense seekers, security etc. It is popular in most of the modern industrial plantsfor the measurement of bulk materials sincethe digital approach is more flexible and program updates are very easy. Here,our aim is to use FMCW radar operating in the frequency range of 24-24.
3 GHz soas to obtain much better and accurate results.Currently available products in the market give accuracy of about 3mm-10mmwhich causes large loss in mass storage tanks (40m in height x 40m in radius). Themain focus of this project is to reduce that error of measurement to about0.05mm. The work for this project hasbeen effectively carried out and the software simulation has been done andtested successfully.
Once this system is deployed, the losses faced by theindustries for the same can be minimized. A lot of intense research is beingdone to find out the best hardware components that could be used to suchaccurate implementation. Due to hardware and environmental constraints we aretargeting the expected hardware accuracy between 0.5mm and 1mm, which will befar better than the current available products. The ultimate idea is toproductize a device which gives accuracy less than or equal to 1mm and save thelosses of the fuels due to inaccurate measurement.
II. LITERATURE SURVEY1 M. Challal, A. Azrar, H. Bentarzi, Electrical Engineering andElectronics DGEEFSI, University of Boumerdes UMBBBoumerdes, ALGERIA published apaper on “Microstrip Design of Low Noise Amplifier forApplication in NarrowBandand WideBand”. Here a low-noise amplifier (LNA) is presented in thispaper. TheLNA is designed and optimized for narrowband andwideband operations along withminimum noise figure around 24GHz (K-Band). The designed LNA employs microstripinput andoutput matching networks; it achieves a noise figure of 3.
85 dBand10.55 dB of gain along with 10.27 dB and 17.83 dB of inputand output returnlosses, respectively for its narrow band.
Whereas for its wideband itaccomplishes a gain of 6.5 dB with ±0.3 dBflatness from 24 to 25.25 GHzwideband frequency range, thenoise figure obtained for the presented LNA is inclose proximityto the minimum noise figure over 23 – 24.5 GHz frequency range.
2 Jeffrey Keyzer, Anthony Long published a paper on “A Dual-Stage Low-Noise Amplifier for 24 GHz UsingPackaged p-HEMTs” where amplifier designs exist at 24 GHz which employ the useof inexpensive, packaged components. A designwas presented which used commonlyavailable components and construction techniques to achieve a noise figure of2.0 dB and 14 dB of gain.
3 Zhao Zeng-rong, Bai Ran ElectronicsDepartment of Hebei Normal University, Shijiazhuang, China published a paper “AFMCW Radar Distance Measure System based on LabVIEW” which presents anacquisition and process system for frequency modulation continuous wave (FMCW)radar. The procedure was designed in LabVIEW7.0. The system adopted FMCW radarsensor and high-quality data acquisition card. The intermediate frequency (IF)signal of the FMCW radar could be collected in time. The intermediatefrequency, distance and velocity forward vehicle can be calculated by animproved algorithm. It can give the alarm when a collision danger is predicted,and it can assist the driver to brake control, thus some collision accidentswill be avoided.
The design method of the system and test data is givensimultaneously. The effectiveness of the designed system is verified by somereal tests. 4 CunlongLi ,Weimin Chen, Gang Liu from Collegeof Optoelectronic Engineering, Chongqing University, China; published a paper “A Noncontact FMCW RadarSensor for Displacement Measurement in Structural Health Monitoring” whichinvestigates the Frequency Modulation Continuous Wave (FMCW) radar sensor formulti-target displacement measurement in Structural Health Monitoring (SHM).The principle of three-dimensional (3-D) displacement measurement of civilinfrastructures is analyzed.
The requirements of high-accuracy displacement andmulti-target identification for the measuring sensors are discussed. Thefundamental measuring principle of FMCW radar is presented with rigorousmathematical formulas, and further the multiple-target displacement measurementis analyzed and simulated. 5 Johanngeorg Otto published a paper on “RadarApplications in Level Measurement, Distance Measurement and NondestructiveMaterial Testing” which presents first an overview over commercial microwavesensor systems in the field of level measurement of liquids and bulk goods.Advances in microwave technique and digital signal processing created newmarkets in process engineering. There a two classes of microwave level sensorsystems: high precision sensor for storage tanks and sensors for process tankwith hard measuring conditions like high temperature, pressure, turbulences,agitators etc.
There exist CW as well as pulse radar systems. The signalprocessing in tanks differs from standard free space distance measurementbecause of the comparatively small measuring distance and the variety ofmultiple and unwanted echo paths. Special features of this signal processingare presented.
6 SerdalAyhan, Mario Pauli, Thorsten Kayserfrom Karlsruhe Institute of Technology (KIT), Germany published a paper on”FMCW radar system with additional phase evaluation for high accuracy rangedetection” which presents a radar based approach of range detection dependingmainly on the utilized radar principle which allows either high accuracy orhigh unambiguous ranges. For the most widely used FMCW radar the entiredistance is not restricted in the meter range whereas the achievable accuracydirectly depends on the bandwidth. An improvement is only possible if systemparameters are changed or a smart signal processing is applied.
In this paperan approach was described which extends the FMCW radar with an additional phaseevaluation to facilitate also high accuracy using low-cost radar components andnone intensive processing methods. 7 Hyeokjin Lim and Seongjoo Lee Department ofElectrical Engineering, Korea published “A Short Range FMCW Radar System withLow Computational Complexity” in which a short range FMCW (Frequency ModulatedContinuous Wave) radar system with low computation complexity is proposed. In orderto improve the frequency linearity, the proposed FMCW radar system adopts thedigital frequency modulation with the counter and look-up tables for sine andcosine waves in an FPGA (Field Programmable Gate Array).
III. PROPOSED SYSTEMA. Blockdigram of the proposed systemFig. 1: Blockdiagram for FMCW radar (Receiver Section) LNA (Low NoiseAmplifier): Possibly weak signals received by an antenna are amplified andnoise is reduced.Quadrature Mixer: Two copies of the received signal are generated,one 90 degrees delayed with respect to the other, and these are separatelymixed with transmitted signal.
The outputis two signals, viz. I and Q signals. They are samples of the same signal thatare taken 90 degrees out of phase, and they contain different information.Higher frequencies are down-converted tolower frequenciesLPF: It is a filter which passes low-frequency signals and blocks,or impedes, high-frequency signals.ADC: It converts the analog signal to Digital signal which is thensent to the Digital Signal Processing section.Signal Processing: Here the digital signal is processed usingLabView software and the fluid level in the tank is calculated.
B. Working principleA high-frequencysignal of 24GHz is first emitted using a radar in the proposed system. Thissignal after hitting the target gets reflected and the reflected frequency iscaptured by the system. A difference between the transmitted and the reflectedfrequency(?f) is calculated and is transformed using Fourier transformation(FFT) for further calculations. The distance calculationis done on the basis of this difference a much accurate result is obtained.
Fig 2:Graphical representation of Transmitted wave and Received wave Here, D= c.l?tl / 2 = c.l?tl / 2.(df/dt)Where, c0 = speedof light = 3·108 m/s?t = delaytime s?f =measured frequency difference HzR = distancebetween antenna and the reflecting object df/dt =frequency shift per unit of time The delay(?t) is proportional to difference between the transmitted and received wave(?f). IV. Hardware Components RequiredThe hardware being employed for such high-frequency circuit implementation are:A. Rogers RTDuroid RO5880 substrate (0.
787mm)This substrate is specifically chosen so as the handle the24-24.3GHz frequency. This substrate can withstand this high frequency withvery minimal, Lowestelectrical loss for reinforced PTFE material, Low moisture absorption,Isotropic, Uniform electrical properties over frequency, Excellent chemicalresistance. Complete implementation of LNA (Low Noise Amplifier), Quadraturemixer circuit and SSC (Signal Conditioning Circuit) will be done on 20 mil (1thousand of an inch) substrate which is able to handle such high frequencies.B.
High-frequencyLow Noise Amplifier ProcessorA low noise amplifier (LNA) significantly improves theperformance of most radio communications systems. To facilitate theconstruction of a transceiver at 24.192 GHz, a dual stage LNA has been designedusing the NE32984D.C. Other Accessories:Coaxial cables, connectors, high-frequency resistors, ultra-capacitors,and inductors are been employed to give maximum output. V. DesigningA.
LNA DesignFig3: LNA architectureThe key figures of merit for a down conversion system arethe system noise temperature and system gain. For the purposes of this circuit,the down conversion system consists of a low noise amplifier followed by amixer, an IF amplifier, and another mixer. This dual conversion architecturepermits the use of widely available and high-qualityVHF single sideband receivers. A low noise front end with high gain results inthe reduction in noise contributed by the following stages. Adding an amplifieris based on the need to increase G1 and decrease F1 inF = F1 + (F2-1)/G1 + (F3-1)/G2*G1 +….
Depending upon the frequency various stages can be added.A single stage of this device gives a 12dB and 2.0 Noise Figure. We will beimplementing a single-stage for the same.B.
Quadrature Mixer DesignFig. 4: Structural diagram ofQuadrature Mixer The block diagram shows the use of a quadrature mixer andcomplex-baseband architecture. In this case, the received signal mixes with thecos() and sin() versions of the LO, with a duplicated IF chain and ADC for thein-phase (I) and quadrature (Q) channels.
C. Reflected Power CancellerFig. 5: Power Canceller Circuit FMCW radar withsingle antenna causes leakage of transmitted signal into the receiver which canreduce the dynamic range and degrade the receiver sensitivity. One of thegreatest challenges in designing continuous-wave monostatic radar lies inachieving sufficient isolation between the transmitter and the receiver. Anovel adaptive reflected power cancellation technique in real-time digitalsignal-processing is proposed to nullify the transmitter leakage at thereceiver front-end to achieve high isolation. With the digital implementation,the proposed scheme requires limited hardware and reduced logical elements thanthe previously reported adaptive digital implementations.
VI. Results Fig. 6: Circuit diagram for evaluation of signals.
The entire system is been simulated in theLabView software for all the parameters that can affect the precision.Different parameters and their constraints were addressed withthesingle aim of degrading errors in the measuringsystem.The system on simulation gives the output of 0.05mm. Currently, the hardware-based research is been done takinginto account the various constraints of the hardware. The hardware designs forvarious blocks ofthereceiver system isbeen done for LNA, quadrature mixer and signal conditioning circuit. The implementation of this high-frequency hardware is the biggestchallenge of the project.
Every minor parametersuch asasubstrate, environmentalconditions, temperatures ranges for system functioning, heat sink, accessories,etc. is taken into account for selectingthe materials for hardware implementation.Further,we will be using here is a horn antenna which is also under designing.
And lastly, we are also currently on designingstage of Low Noise Amplifier (LNA). The LNA is designed for 24 GHz usingp-HEMT. Future ScopeThepresent study has been made to suggest and develop some tools which willeventually be useful to the governments, industries, owners and/or contractorsfor timely and accuratemeasurements of large infrastructure projects atareasonable cost and of a specified quality.References1 Microstrip Design of Low Noise Amplifier forApplication in NarrowBandand WideBand, M.
Challal, A. Azrar, H. Bentarzi, Electrical Engineering and ElectronicsDGEEFSI, University of Boumerdes UMBBBoumerdes, Algeria2 A Dual-Stage Low-Noise Amplifier for 24 GHzUsing Packaged p-HEMTs, Jeffrey Keyzer, Anthony Long3 A FMCW Radar Distance Measure System based on LabVIEW, Zhao Zeng-rong,Bai Ran Electronics Department of Hebei Normal University, Shijiazhuang, China4 A Noncontact FMCW Radar Sensor for Displacement Measurement inStructural Health Monitoring, CunlongLi ,Weimin Chen, Gang Liu from College ofOptoelectronic Engineering, Chongqing University, China5 Radar Applications in Level Measurement, Distance Measurement andNondestructive Material Testing, Johanngeorg Otto6 FMCW radar system with additional phase evaluation for high accuracyrange detection, SerdalAyhan, Mario Pauli, Thorsten Kayser from KarlsruheInstitute of Technology (KIT), Germany7 A Short Range FMCW Radar System with Low Computational Complexity, HyeokjinLim and Seongjoo Lee Department of Electrical Engineering, Korea