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Microwaves, Communications, Antennas and Electronics Systems, 2009. COMCAS 2009. IEEE International Conference on

Date 9-11 Nov. 2009

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Displaying Results 1 - 25 of 152
  • Active RFID TAGs system analysis of energy consumption as excitable linear bifurcation system

    Publication Year: 2009 , Page(s): 1 - 9
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (132 KB) |  | HTML iconHTML  

    Active RFID TAG system can be represent as Voltage source (internal resistance), Parallel Resistor, Capacitor, and Inductance circuit. Linear bifurcation system explain Active RFID TAG system behavior for any initial condition V(t) and dV(t)/dt. Active RFID's Coil is a very critical element in Active RFID TAG functionality. Active RFID TAGs system energy consumption can be function of many variables : q(m), u(m), z(m), t(m), tms (m), when m is the number of TAG IDs which are uniformly distributed in the interval [0,1). It is very important to emphasis that basic Active RFID TAG, equivalent circuit is Capacitor (Cic), Resistor (Ric), L (RFID's Coil inductance as a function of overall Coil's parameters) all in parallel and Voltage generator Vs(t) with serial parasitic resistance. The Voltage generator and serial parasitic resistance are in parallel to all other Active RFID TAG's elements (Cic, Ric, and L (Coil inductance)). Optimization can be achieved by Coil's parameters inspection and System bifurcation controlled by them. Spiral, Circles, and other Active RFID phase system behaviors can be optimize for better Active RFID TAG performance and actual functionality. Active RFID TAG losses also controlled for best performance and maximum efficiency. View full abstract»

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  • Systematic design of RSSI and logarithmic amplifiers circuits

    Publication Year: 2009 , Page(s): 1 - 4
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (347 KB) |  | HTML iconHTML  

    This paper presents a systematic design methodology for logarithmic amplifiers and receiver signal strength indicator (RSSI) circuits. A close expression for the maximum detection error using a piece wise linear approximation of the logarithmic function was derived. The design methodology has been proposed that optimizes the power consumption and 3 dB bandwidth of a single stage CMOS limiting amplifier according to the common mode voltages in order to meet the voltage gain and detection error requirements. The results for the RSSI circuit indicate 70 dB dynamic range, 3 dB bandwidth of 500 MHz and maximum detection error of 0.6 dB in the temperature range between -40°C and +70°C. The overall power consumption equals to 10.3 mW in 180 nm CMOS process technology. View full abstract»

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  • Distortion mechanisms in supply modulation of polar transmitters

    Publication Year: 2009 , Page(s): 1 - 4
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (226 KB) |  | HTML iconHTML  

    The distortion mechanisms in supply modulation introduced by the PWM generator, the frequency response of DC regulator and the limited bandwidth of the high frequency recovery unit are analyzed for EDGE polar transmitters. It is demonstrated that there is an optimum regulator bandwidth that minimizes the total residual energy originated from the PWM generator and the low pass filter characteristics of the buck converter. The output spectrum was analyzed for a 5 MHz PWM clock frequency buck converter. The results show that in order to meet EDGE transmission mask requirements, the bandwidth requirements of the high frequency recovery unit should be at least 10 MHz for 300 KHz converter bandwidth while a 95 KHz converter bandwidth demands for no compensation at high frequencies. View full abstract»

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  • Single pixel THz detector for remote imaging

    Publication Year: 2009 , Page(s): 1 - 4
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (955 KB) |  | HTML iconHTML  

    High-resolution single-pixel detector operating near 0.33 THz is described. It consists of FMCW transmitter based on multiplying chain (x32) and heterodyne receiver with sub-harmonic mixer. The X-band FMCW synthesizer is employed as a driver of multiplying chain and LO of the mixer. The Gaussian-beam antennas are used in the Rx and Tx channels. The detector was mounted on the scanning platform and can be employed in various homeland security applications where the remote detection of hidden objects both metal and plastics is required. View full abstract»

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  • Dual frequency cavity resonator for atomic manipulation and spectroscopy

    Publication Year: 2009 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (489 KB) |  | HTML iconHTML  

    We propose a new approach for the design of a cavity for atom vapor based devices, where atomic manipulation via two frequencies is required. The cavity provides a homogenous field at two different frequency bands -6.8 GHz and 2 MHz; the first frequency is supported by a cylindrical resonator with conductive walls and dielectric bases, the second frequency is applied from an external source and penetrates into the cavity by taking advantage of the skin effect phenomenon of the resonator thin metal walls. In the specific design presented here, the cavity contains a glass cell with Rubidium vapor and enables the two-photon manipulation of the 52S1/2 ground state manifold. View full abstract»

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  • Optimization of the carrier tracking loop for 8PSK transmission

    Publication Year: 2009 , Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (96 KB) |  | HTML iconHTML  

    The performance of discrete-time decision directed (DD) first order phase locked loops (PLL) for a 8PSK modulated signal is evaluated under the disturbance of thermal noise and 1/f2 phase noise. A continuous time model is developed that closely approximates the loop's behavior. Fokker-Planck techniques are applied to compute the mean time to lose lock for both PLLs. We optimize the loop filter using the MTLL as the optimization criterion. Monte-Carlo simulation results are presented to validate the analytic analysis. Applicability of the results for second order PLL is discussed. We apply the analytic results to investigate the necessity of pilots for 8PSK reception in DVB-S2. View full abstract»

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  • Linear FM radar operating in the Tera-Hertz regime for concealed objects detection

    Publication Year: 2009 , Page(s): 1 - 4
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (554 KB) |  | HTML iconHTML  

    Sub-millimeter and terahertz waves maintain reasonable penetration depth in certain common materials, such as cloth, plastic, wood, sand and soil. Therefore, THz radiation can detect concealed weapons since many non-metallic, non-polar materials are transparent to this type of radiation (and are not transparent to visible radiation). Target compounds such as explosives and illicit drugs have characteristic THz spectra that can be used to identify these compounds. Investigation, design and development of a sub-millimeter wave remote sensing RADAR system for homeland security applications are presented. The RADAR, operating at 330 GHz is based on transmission of a frequency modulated continuous wave (FMCW) and aimed at detection of concealed objects for ranges up to 20 m. The system consists of 2 horn-lens antennas integrated with a homodyne transceiver. The synthesized linear FM signal with a frequency span of 200 MHz at X-band is multiplied by a factor of 32 to generate the transmitted Tera-Hertz wave. Using a splitter, the signal is fed to an antenna and to a local oscillator port of a second harmonic balanced mixer. As a result, an intermediate frequency signal is obtained, containing the information on the target. Distance measurements were made by performing data acquisition and signal processing commercial programs, resulting in a range resolution better than 1 cm. Preliminary Tera-Hertz imaging was also carried out to perform a three-dimensional image of the object. View full abstract»

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  • A novel semi-analytic method for 3D scattering problems

    Publication Year: 2009 , Page(s): 1 - 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (245 KB) |  | HTML iconHTML  

    The method for the solution of scattering problems with homogeneous dielectric scatterers immersed in uniform dielectric media based on a single coordinate multipole expansion and the Stratton-Chu integral is proposed in the present talk. Its convergence is proved. The sources of ill-conditionality of the constitutive algebraic system are established. The method of its regularization based on the use of stabilization terms is suggested. The method of iterative accumulation of errors has been found to generate regularization factors. Additionally, the method of discrete drains is being proposed, as a method for checking the accuracy of the multipole approximation. For the sake of validation, the numerical analysis is performed for different testing objects. View full abstract»

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  • The use of 3D electromagnetic simulation tools in the design of Microwave Integrated Circuits: An accuracy assessment

    Publication Year: 2009 , Page(s): 1 - 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (202 KB) |  | HTML iconHTML  

    The accuracy of well-known commercially available 3D electromagnetic simulation tools has been examined through designing, building, and testing several original microwave integrated circuits. It turns out that the accuracy of the tools considered is acceptable for most practical purposes, for frequencies up to 3 GHz (upper limit of our investigation). View full abstract»

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  • A wideband LNA with dual-feedback for TV tuner

    Publication Year: 2009 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (595 KB) |  | HTML iconHTML  

    A wideband LNA is the first amplifying stage in TV tuner system. It requires a low noise figure with a sufficient gain and a high linearity such as high IIP2 and IIP3 due to the many adjacent channels. This paper represents the wideband CMOS LNA using a dual feedback for the tuner application, which can suppress the second and the third order distortions with a low noise and a suitable gain. In the dual feedback, the weak negative feedback improves the linearity of the transconductance partially, thereby maintaining the high gain and low noise. The residual distortion and the distortion of the buffer are cancelled by the positive feedback. Consequently, the proposed wideband LNA with the dual feedback improves noise figure and linearity with a high gain. The LNA fabricated in 0.18 ¿m RF CMOS demonstrates the expected performances. View full abstract»

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  • A hybrid wafer level packaging technique for multi-chip interconnect using low loss organic layers

    Publication Year: 2009 , Page(s): 1 - 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (303 KB) |  | HTML iconHTML  

    This paper presents a new wafer level packaging (WLP) technique that combines thin, low cost organic layers with high performance MMICs. More specifically, we present a GaAs-based single stage amplifier covered with layers of a low loss liquid crystal polymer organic material. It was observed that the RF performance of the MMIC is virtually unaffected by this technique unlike conventional packaging processes that degrade the RF performance due to the overlay of the dielectric material on the MMIC. The insertion loss for the laser ablated 50 micron vias was minimal up to 20 GHz. These results show that the hybrid WLP can be successfully implemented with virtually no performance degradation. View full abstract»

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  • Overview of GPS antennas

    Publication Year: 2009 , Page(s): 1 - 4
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (267 KB) |  | HTML iconHTML  

    GPS antennas should cover most of the sky and see as much satellites as possible. The antenna should have a broad radiation beam and low gain. The antenna must be well-matched in the relevant frequencies and be Right Hand Circular Polarized. The key factor in GPS systems for high position accuracy and for short acquisition time is the antenna. It is the objective of this paper to present the requirements from GPS antennas and to describe and compare different antenna types. View full abstract»

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  • Constant loss miniature 45nm RF-CMOS 24 GHz phase shifter

    Publication Year: 2009 , Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (327 KB) |  | HTML iconHTML  

    We present design and characterization of an integrated passive analog phase shifter at 24 GHz in a commercially available 45 nm RF-CMOS process. The design is based on a well known RC bridge topology which was optimized for maximum phase shift and minimal amplitude response variation versus phase and frequency. Phase is controlled by varying DC voltage on a varactor, resulting in 60° maximum phase shift with 0.1 dB amplitude variation at 24 GHz. The size of the phase shifter circuit excluding pads and input/output buffers is 40×50 ¿m2. View full abstract»

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  • Cutoff wavelengths of metallic waveguides with elliptical cross section

    Publication Year: 2009 , Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (240 KB) |  | HTML iconHTML  

    The cutoff wavelengths ¿cmn of metallic waveguides with elliptical cross section are determined analytically. Two alternative methods, namely, a field and a shape perturbation method are used in the proposed analysis. Exact, closed form expressions, free of Mathieu as well as of Bessel functions, are obtained for the cutoff wavelengths, when the solution is specialized to small values of the eccentricity of the elliptical cross section. Numerical results for all types of modes are also included. View full abstract»

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  • High resolution high power W-band spectroscopy system (92–100 GHz)

    Publication Year: 2009 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB) |  | HTML iconHTML  

    High resolution high power W-band (92-100 GHz) spectroscopic system was constructed and experimentally tested. The system is based upon two parabolic mirrors, high power high resolution continuous wave tunable THz source and unique THz detector. The spectrometer is fully computerized. The quasi-optical system was design to transfer maximum beam power with minimum aberrations and minimum system internal reflections. Stray refractions were eliminated by placing absorber blocks around the system. Spectral resolution of tens of kHz is achievable. The system was designed to measure transmission function of sample using wide collimated beam of 75 mm diameter in order to simulate THz imaging situation. View full abstract»

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  • Low-cost high-efficient 10-Watt X-band high-power amplifier

    Publication Year: 2009 , Page(s): 1 - 6
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (882 KB) |  | HTML iconHTML  

    A high power X-band amplifier with an output power over 10 Watts and a Power Added Efficiency (PAE) in excess of 40 percent has been developed. The design was fabricated in a 0.25 ¿m pHEMT GaAs process (WIN Semiconductor PP25-01). The small die area in combination with a 6-inch wafer technology provides the possibility for low cost production of a high performance X-band T/R chipset. View full abstract»

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  • Assessment of optimal exposure time of broadband microwave radiation on bone marrow cell vitality

    Publication Year: 2009 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (241 KB) |  | HTML iconHTML  

    In this study, we investigated the effect of exposure time of broadband microwave radiation on bone marrow cell cultures. The cells were illuminated by electromagnetic radiation using a broadband noise source operating in the range from 60 to 400 GHz. The vitality of the cells was estimated as a proportion of dead cells. All experimental results were treated employing statistical methods. The optimal exposure time was determined for specific experimental conditions. The cytoprotective influence of mm-wave radiation was assessed. View full abstract»

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  • Attenuated Total Reflectance (ATR)-FTIR spectral measurements in MIR and FIR (THz) range

    Publication Year: 2009 , Page(s): 1 - 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (274 KB) |  | HTML iconHTML  

    Mid-Infrared (MIR) spectroscopy is an extremely reliable and well recognized fingerprinting method. Far-Infrared (FIR) and THz spectroscopy is quite difficult since it requires special sources, quasi optics, special materials and sensitive detectors. The technique of Attenuated Total Reflectance (ATR) has in recent years revolutionized solid and liquid sample analyses because it combats the most challenging aspects of infrared analyses, namely sample preparation and spectral reproducibility. An attenuated total reflection accessory operates by measuring the changes that occur in a totally internally reflected infrared beam when the beam comes into contact with a sample. In this work a spectral measurements using the ATR-FTIR technique will be presented. Spectral measurements of liquids and powders in the THz regime will be discussed and analyze. Furthermore, we will present ATR-FTIR spectral measurements that were carried out for commercial companies. View full abstract»

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  • Fast and noise-aware power-up for on-die power gated domains

    Publication Year: 2009 , Page(s): 1 - 5
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (270 KB) |  | HTML iconHTML  

    On-die PSO is used for leakage power reduction. The power-up process at PSO exit (gated supply voltage recovery) is usually designed to be relatively slow process. This is done in order to keep quiet continuous power supply of always powered-on devices. We propose a way of acceleration the power-up, while holding the continuous power supply at acceptable level of noise. This is achieved by monitoring the IR droop level of the continuous power supply. It allows significant reduction of the power-up time with no functionality impact. The theoretical background, the arrangement schematics and the simulation results are presented. View full abstract»

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  • Fibers vs. coax for RF delay line applications

    Publication Year: 2009 , Page(s): 1 - 2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (117 KB) |  | HTML iconHTML  

    A comparison between the RF-over-fiber and the RF-over-coax technologies is presented. It is shown that while in relatively short delay lines the coax technology will do, for delay lines longer than a certain distance the fiber technology has a clear advantages: Beyond several microseconds it is better in terms of volume, noise figure and cost. View full abstract»

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  • A non-linear model for analysis of limit cycle behavior in CDR with bang-bang phase detector

    Publication Year: 2009 , Page(s): 1 - 4
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (318 KB) |  | HTML iconHTML  

    Analysis of the control loop of clock-data recovery circuits (CDR) that use bang-bang phase detector is complicated by the fact that the loop behavior is determined by the jitter profile of the input signal. We present a method for constructing a non-linear average deviation model that permits fast simulation of the limit cycle behaviors. In addition, linear AC analysis performed on the model allow observing the control loop transfer functions. The main idea is to model the average behavior of the non-linear phase detector using the cumulative density function (CDF) of the total jitter. The random jitter (RJ) component is assumed Gaussian and the deterministic jitter (DJ) is modeled using a histogram approach. The total jitter CDF is obtained by convolving the RJ and DJ components. For ease of implementation in VerilogA, we use a polynomial approximation for the Gaussian CDF. Finally we present simulation results that show correlation with the long time consuming full circuit simulations. View full abstract»

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  • An RSA processor for near real-time operation

    Publication Year: 2009 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (202 KB) |  | HTML iconHTML  

    The goal of this paper is to research the feasibility of designing and implementing an economical architecture for the real time computation of RSA algorithm, in a sense that the architecture could be implemented on single ASIC with standard logic and power supply. The main challenge in implementing such a design comes out of a need to make arithmetic computations involving very large numbers with bit lengths of thousands of digits. To overcome this, special design of hardware is needed at the algorithms level, and also at the circuit level. The final implementation of our hardware is based on four known algorithms leveraging the use of a CCSA (Carry-Completion-Sensing-Adder) as the building block of the design. This implementation makes it convenient to benefit from a fast hardware adder in a simple algorithm choice, while attempting to keep hardware costs down. The results support the initial assumption that it is possible to implement an embedded RSA encryption engine for real-time or near real-time operation by exploiting the features of a custom hardware processor. View full abstract»

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  • System power consumption minimization for multichannel communications using cognitive radio

    Publication Year: 2009 , Page(s): 1 - 5
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (182 KB) |  | HTML iconHTML  

    Power consumption has been a significant issue for many mobile and wireless devices, especially those with high rate applications. This paper presents a methodology and framework to minimize system power consumption for multichannel communications using cognitive radio (CR) based on the application quality of service requirement, the channel condition, and the radio capabilities and characteristics. The CR framework enables an adaptation process that is aware of the radio (component) capabilities and characteristics. This paper mathematically formulates a system power consumption minimization problem under a rate constraint for multichannel communications and develops numerical solutions. Simulation results show that the knowledge of the radio capabilities and characteristics can help to reduce system power consumption significantly (e.g., up to 55% for a multichannel system with Class A power amplifiers). View full abstract»

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  • Multi-cantilever HEMT-based resonant sensor

    Publication Year: 2009 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (135 KB) |  | HTML iconHTML  

    In this paper resonant sensor based on micro-machined high-electron mobility transistor (HEMT) in which multiple suspended resonant cantilevers serve as floating gates is proposed and its analytical and lumped equivalent circuit models are developed. The proposed HEMT-based multi-cantilever resonant sensor enables electrostatic actuation and electrical readout. Mass absorption by a cantilever results in the change in its mechanical resonant frequency. Mechanical oscillations of such a cantilever excited electrically control the source-drain current. Thus, its resonant frequency shift can be detected as a frequency shift in the resonant peak of the source-drain current. Mechanical oscillations of each cantilever and electromechanical transducer are represented by relevant circuit components. The developed equivalent circuit of multi-cantilever resonant sensor was used to simulate its frequency response using Is-Spice software. The simulation reveals an enhanced source-drain current with a peak at a single frequency for the array of the identical cantilevers. In the case of multiple different cantilevers the simulated source-drain current reveals peaks at frequencies corresponding to mechanical resonances of the cantilevers, as expected. View full abstract»

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  • The influence of antenna directivity on physical layer simulations of 802.11n devices

    Publication Year: 2009 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (158 KB) |  | HTML iconHTML  

    Integration of multiple antennas into 802.11n devices gives raise to many interesting questions. One of the most frequent questions is the desired antenna radiation properties of each antenna elements. Directive antennas are often suggested in an effort to increase the power link budget by increasing antenna gain in the azimuth plane. However, the impact of preferred directions on the received multi-path signal is seldom considered. In this presentation, we improve upon already existing channel models to include antenna directivity in the physical layer (PHY) simulation. The link budgets for 2×2 and 2×(3 choose 2) MIMO systems are presented including omni and directive antenna patterns in a variety of array configurations. View full abstract»

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