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Microwaves, Radar and Remote Sensing Symposium, 2008. MRRS 2008

Date 22-24 Sept. 2008

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Displaying Results 1 - 25 of 73
  • Integrated hardware reduction schemes for retrodirective array architectures

    Publication Year: 2008 , Page(s): 12 - 15
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1579 KB) |  | HTML iconHTML  

    This paper will present and review a few recent developments in retrodirective array architectures that integrate schemes for hardware reduction. The proposed systems offer simplified architectures for retrodirective array application that can lead to low-cost solutions for various communication scenarios. First, the flexibility of the retrodirective architecture is discussed with simple integration into sparse arrays. Combination of a sparse array with a switching network allows a single phase conjugator to be shared by four radiating elements within a six element aperture. Finally, an example of a conformal sparse retrodirective array is presented in a potential mobile platform application that is known to have limited hardware requirements. View full abstract»

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  • Reconfigurable reflectarrays based on RF MEMS technology

    Publication Year: 2008 , Page(s): 16 - 21
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (6896 KB) |  | HTML iconHTML  

    Innovative and high-performance antenna systems are required by the increasing demand of bandwidth and service quality in modern communication systems, as well as in a number of industrial applications. At the same time, new technologies and devices are emerging to comply with such specifications. Thanks to their inherent low costs and high performance, RF-MEMS can potentially bring in completely new classes of tuneable devices and circuits for RF applications. This paper focuses on the possible use of RF-MEMS in beam scanning antennas and particularly in reconfigurable reflectarrays. After reviewing some of the basic principles of such systems, two projects recently carried out in the framework of the AMICOM Network of Excellence are described. Besides the general features of these antennas, currently under test, the innovative single wafer architecture and the relevant packaging issues are specifically addressed. View full abstract»

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  • Dual band reconfigurable slot antenna with high frequency ratio

    Publication Year: 2008 , Page(s): 22 - 25
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2188 KB) |  | HTML iconHTML  

    In this paper, a design of compact dual band reconfigurable slot antenna is presented. The dual band operation is realised by effectively changing the slot electrical length using solid state shunt switches. Two resonant frequencies are obtained with the frequency ratio of 2:1. Although the ratio is high, good matching is achieved on both resonant frequencies without the need for a reconfigurable matching network. Also, radiation pattern, polarisation and efficiency remain reasonable similar at both frequencies. Computation results are confirmed with the experimental results. View full abstract»

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  • Comparison of two configurations of a four-reflector beam-waveguide for a large space communication facility

    Publication Year: 2008 , Page(s): 26 - 29
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1417 KB) |  | HTML iconHTML  

    In this paper we perform full-wave two-dimensional (2-D) simulation and performance comparison of the E-polarized beam wave guidance and scattering by two variations of a typical fragment of quasioptical feeding circuit of a deep-space communication antenna. The fragments are similar and consist of a chain of four finite-size reflectors and mirrors with varied position of the second pair. The feed beam generated by the aperture of a corrugated horn is simulated with the incident complex-source-point (CSP) field. Numerical solution is obtained from the coupled singular integral equations (IEs) discretized using new quadrature formulas of interpolation type that take full account of the IE kernel singularity and the edge behaviour. View full abstract»

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  • On realization of the transition radiation antenna

    Publication Year: 2008 , Page(s): 30 - 33
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1178 KB) |  | HTML iconHTML  

    Consideration is given to the possibility of realization of the transition radiation antenna. The radiation is formed by relativistic point charge scattering on a metal surface. A plane disk is proposed to be used as a reflector. For the spectrum of a point charge field 0 Hz les f les 1 THz the disk diameter should not exceed 1 m. The discrete character of radiation formation is marked. The antenna is a UWB antenna of a low-level power and can be used in the space-based systems. View full abstract»

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  • Coherent scattering from distributed targets

    Publication Year: 2008 , Page(s): 36 - 41
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1609 KB) |  | HTML iconHTML  

    Based on the formulation for coherent backscattering from distributed targets previously published by the first author, this paper presents a unified formalism for incorporating the small amplitude, the small slope, the physical optics as well as a ldquotwo-scale modelrdquo approximation into analyses of backscattering by irregular air-dielectric interfaces. The distinguishing feature of this approach is that it takes explicit account of the antenna radiation properties and provides a direct means of numerically assessing the effects of spatial coherence of the surface irregularities on the receiver response. In particular, this leads to a generalization of the normalized backscattering cross-section which becomes dependent on both the antenna radiation properties and surface scattering characteristics. Numerical results obtained under the small amplitude approximation show that spatial coherence of the surface irregularities can lead to significant deviations from the classical Bragg scattering formula. View full abstract»

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  • Status of advanced scattering distortion system analysis for navaids and radar - examples of A380 and wind turbines

    Publication Year: 2008 , Page(s): 42 - 47
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (6066 KB) |  | HTML iconHTML  

    Modern systems, e.g. navigation, landing, radar and communication systems, rely on the physics of antennas and propagation. Their electrical performance is determined by the intended radiation and by the scattering of distorting objects. The scattering analysis is an integral part of the system simulations. The modeling of the antennas, the environment, the distorting objects and of the system itself are the basic steps of the simulation process. This paper describes the aspects of state-of-the art system simulations by evaluating actual examples, such as the new A380 with respect to the landing system ILS and wind turbines WT to radar systems, in particular to weather radar. View full abstract»

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  • Material parameter measurements for microwave anti reflection coating development

    Publication Year: 2008 , Page(s): 48 - 53
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2734 KB) |  | HTML iconHTML  

    The main steps for characterization and measurement of microwave absorbent materials in the 1-10 GHz range is introduced. The coaxial reflection-transmission type of material parameter measurement is analyzed in detail and the main measurement error is corrected. The microscopic material particle parameter measurement concept is also presented using different mixing rule laws to determine the material parameters of the single particles from the macroscopic parameters. Two dimensional FDTD simulations have been used to model the behavior of mixed electric and magnetic type of material. View full abstract»

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  • Analysis of generalized polarimetric measurement equations for Stokes polarimetry techniques

    Publication Year: 2008 , Page(s): 54 - 57
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1177 KB) |  | HTML iconHTML  

    We study the errors variances for some popular strategies of Stokes vector measurement. It was shown that the errors of the Stokes parameters measurement are non-uniformly distributed for different measurement strategies. This fact can be used in optimization of the polarization parameters measurement. View full abstract»

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  • Coherent multilateration systems

    Publication Year: 2008 , Page(s): 60 - 65
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1264 KB) |  | HTML iconHTML  

    Passive coherent location systems using ldquotransmitters of opportunityrdquo like radio or TV broadcasters, GSM base stations, satellite communication and GNSS signals has reached a substantial attention in the last years. In this paper the coherent location system, based on bistatic radar principle with multiple non-cooperative transmitters is described and various aspects of signal processing and signal parameters are discussed. View full abstract»

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  • A compact highly sensitive radiometer for thermal sounding of atmosphere in 5 MM band

    Publication Year: 2008 , Page(s): 66 - 70
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2291 KB) |  | HTML iconHTML  

    Design and characteristics of a compact highly sensitive direct detection MMIC radiometer of 5 MM wave band with a goal of atmosphere temperature profile determination are presented. The radiometer has bandwidth 56.6 plusmn 0.25 GHz and fluctuation sensitivity 35 mK/Hz1/2/65 mK/Hz1/2 in a ldquototal powerrdquo/modulation mode. The radiometer was successfully used for atmospheric temperature profile measurements with the thermal sounder MTP-5. Average deviation of a measured atmospheric temperature profile from the temperature profile constructed according to 11 probes was 0.2 C-0.4 C, average mutual difference of two devises was equal to or less than 0.2 C. View full abstract»

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  • Interactive-mode X-band direction-finder

    Publication Year: 2008 , Page(s): 71 - 74
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1547 KB) |  | HTML iconHTML  

    The compact broad-band direction-finder is presented in this paper. The bearing features and the operation algorithm of the system using the ldquonull-amplituderdquo technique are described in detail. Based on the results of model experiments the sensitivity and resolving capacity of the direction-finder prototype are evaluated. The problems of bearing more than one SHF sources are discussed. View full abstract»

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  • PaRaDe - PAssive RAdar DEmonstrator family development at Warsaw University of Technology

    Publication Year: 2008 , Page(s): 75 - 78
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1903 KB) |  | HTML iconHTML  

    The paper presents a family of passive coherent location (PCL) radar demonstrators, called PaRaDe (passive radar demonstrator), which were developed at Warsaw University of Technology. The systems exploit commercial FM radio transmitters as illuminators of opportunity in order to detect and track airborne targets. In the paper, the details of demonstrator systems are described and the results obtained in tests are presented. View full abstract»

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  • Wide range Time of Flight camera for outdoor surveillance

    Publication Year: 2008 , Page(s): 79 - 82
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (8586 KB) |  | HTML iconHTML  

    This paper presents the application of the time of flight (ToF) cameras to outdoor surveillance. The applications of ToF camera were limited to its non ambiguity distance range, less than 10 meters. We present the problems and the solution for extending the distance use of ToF cameras beyond the non ambiguity range. The distance ambiguity can be solved by measuring the distance with two different frequencies. The needed contrast range of the amplitude image increases with the square of the distance. The efficient use of ToF cameras for outdoor surveillances imposes not only the increase of the illuminating power but also to increase the accuracy of the distance and amplitude images. The ambiguity of the measured distance can be effectively solved if the multiple reflections inside the camera body are reduced. View full abstract»

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  • Availability analysis of the multilateration surveillance system in Kiev (Boryspil) airport

    Publication Year: 2008 , Page(s): 83 - 85
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (944 KB) |  | HTML iconHTML  

    In this paper application of multilateration (MLAT) systems for vehicles localisation is considered. Deployments of such system require special algorithms to be developed and implemented. Analysis of multilateration system deployment is done for Boryspil airport in Kiev, Ukraine. With the help of calculation algorithms, different cases of target position inside the airport area are considered and brief analysis of detection is done. The simulation scheme is developed in order to obtain maximum accuracy of target localization. View full abstract»

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  • Microwave study of ferroelectrics in waveguide

    Publication Year: 2008 , Page(s): 88 - 93
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1249 KB) |  | HTML iconHTML  

    Peculiar feature of ferroelectrics is high dielectric permittivity epsiv which sometimes is accompanied by very big loss tangent tandelta. This is a reason of difficulties to obtain accurate characterization despite of variety of techniques available. This report is devoted to the selection of proper waveguide method for specific cases of bulk or film materials investigation to obtain reliable data of their epsiv and tandelta. View full abstract»

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  • Quasi-optical sapphire resonators for millimeter wave impedance characterization of high-TC superconducting thin films

    Publication Year: 2008 , Page(s): 94 - 97
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1248 KB) |  | HTML iconHTML  

    A number of whispering gallery mode (WGM) dielectric resonators or quasi-optical dielectric resonators (QDR) are proposed by authors for high-temperature superconducting film surface resistance measurement in millimeter wavelength range. Results of comparing advantages and disadvantages of the resonators of three types are presented. The resonators were made of single crystal sapphire in the forms of cylindrical disk, truncated cone and hemisphere with a purpose of work in Ka-band. The peculiarities of resonance frequency spectra, field distribution and interaction of microwave field with the sample under test are considered. In authorspsila opinion each of the resonators has own niche for application. View full abstract»

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  • Amplification of space charge waves of millimeter wave range in transversely inhomogeneous n-GaN Films

    Publication Year: 2008 , Page(s): 98 - 101
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1281 KB) |  | HTML iconHTML  

    Amplification of space charge waves (SCW) due to the negative differential conductivity in n-GaN films placed onto a semi-infinite substrate is investigated theoretically. A general case of transverse inhomogeneous films is considered. The diffusion-drift equations for volume electron concentration were used jointly with the Poisson equation for the electric field. The transverse inhomogeneity results in a decrease of the electron mobility near the surfaces of the film due to surface scattering and, correspondingly, to some decrease of spatial increments of amplification. It is demonstrated that the non-uniform doping can compensate an influence of the surfaces on the spatial increments. It is possible to observe an amplification of SCW in n-GaN films of submicron thicknesses at high frequencies f ges 100 GHz. Also, due to amplification, high (~10 kV/cm) output electric fields of the short wave part of the millimeter wave range can be obtained. View full abstract»

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  • Simulation of electromagnetic wave propagation through dielectric waveguide with p-i-n control element

    Publication Year: 2008 , Page(s): 102 - 104
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1184 KB) |  | HTML iconHTML  

    Simulation of the electromagnetic wave interaction with a p-i-n control element in a dielectric waveguide is presented. The problem has been solved numerically. Our simulation gives the coefficient of propagation like a function of basic parameters of a p-i-n structure. The investigation has demonstrated an efficiency of the control element in a dielectric waveguide in mm wave range. View full abstract»

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  • Microwave oscillations in a cavity with dispersive double negative medium

    Publication Year: 2008 , Page(s): 105 - 107
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2666 KB) |  | HTML iconHTML  

    Microwave oscillations excited by a wideband current pulse in a cavity filled with double negative dispersive medium and bounded by a closed perfectly conducting surface is studied. Some features of eigenfrequencies of such electromagnetic system are presented. Transient field evolution is shown. View full abstract»

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  • Hybrid oscillations in composite resonators with uniaxial hexaferrites

    Publication Year: 2008 , Page(s): 108 - 109
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1123 KB) |  | HTML iconHTML  

    The coupled oscillations are theoretically and experimentally investigated in the composite solid-state resonators (ferrite-dielectric structure). The experiments have been conducted for barium ferrite (BaFe12O19) and strontium hexagallate (SrGa12O19) plates in the saturation region. The calculation is carried out for the first four magnetostatic modes of ferrite plate. The obtained results do correlate with theoretical calculations. View full abstract»

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  • System-in-a-package technology for 3D integration of radar modules

    Publication Year: 2008 , Page(s): 112 - 115
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2351 KB) |  | HTML iconHTML  

    3D thin-film technology including substrate vias and integrated passives is used as a platform for heterogeneous integration of high frequency wireless systems and radar. The features of the technology are first described and next demonstrated with an integrated Doppler radar operating in the Ku band. View full abstract»

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  • High-speed photodiodes for microwave and millimeter-wave systems

    Publication Year: 2008 , Page(s): 116 - 121
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1229 KB) |  | HTML iconHTML  

    The high-speed InGaAs/InP p-i-n photodiodes for microwave generation and frequency up-conversion in microwave and millimeter-wave systems is discussed. Based on numerical simulation study of maximal output microwave power with appropriate optical-to-microwave conversion loss for InGaAsP/ InP partially depleted absorber photodiodes in frequency range from 10 to 60 GHz are presented. The design and operation regime peculiarities of InGaAs/InP p-i-n photodiode as optoelectronic up-converter in radio-over-fiber system are provided. View full abstract»

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  • High-temperature superconductor-films microstrip band-pass filters for extreme working conditions

    Publication Year: 2008 , Page(s): 122 - 125
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1471 KB) |  | HTML iconHTML  

    The microwave microstrip band-pass filters (BPF) for 1.7 GHz manufactured on the basis of normal metal (Cu) thin films, Au/YBCO bilayer films and pure YBCO thin films are investigated. Features of the BPF-construction on the basis of YBCO films are described. The designed high-temperature superconductor (HTS) BPF has electrodynamics characteristics (passband-loss, steepness of transition area from the pass-band to the stop-band etc.), which are inaccessible for normal metal film filters. The influence of moisture, storage in real atmosphere, temperature shocks on electrodynamic characteristics of the microwave HTS BPF with a narrow passband has been investigated. The characteristics of the designed HTS BPF in the hermetic housing were stable after 5 cycles of rapid cooling and heating (300 K darr 77 K uarr 300 K) and more than a year of usage. The designed construction of hermetic housings ensures safety of YBCO films in microwave devices for extreme operation regimes in satellite and cellular communication systems. View full abstract»

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  • Quantum interference in transistors

    Publication Year: 2008 , Page(s): 126 - 129
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1338 KB) |  | HTML iconHTML  

    We consider adiabatic charge transport through transistor based on quantum dot caused by two periodically changing external perturbations. Both the magnitude and the sign of the transmitted charge are extremely sensitive to the configuration of the transistor and to the magnetic field. We find the correlation function characterizing the random value of this pumped charge for arbitrary strength of perturbation. In contrast to previous theoretical and experimental claims, the charge is found not to have any symmetry with respect to the inversion of magnetic field. At strong pumping perturbation, the variance of the charge , <Q2> is found to be proportional to the length of the contour in parametric space. View full abstract»

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