By Topic

Antenna Technology (iWAT), 2011 International Workshop on

Date 7-9 March 2011

Filter Results

Displaying Results 1 - 25 of 123
  • [Front cover]

    Publication Year: 2011 , Page(s): c1
    Save to Project icon | Request Permissions | PDF file iconPDF (369 KB)  
    Freely Available from IEEE
  • Table of contents

    Publication Year: 2011 , Page(s): 1
    Save to Project icon | Request Permissions | PDF file iconPDF (721 KB)  
    Freely Available from IEEE
  • General co-chairs

    Publication Year: 2011 , Page(s): 1
    Save to Project icon | Request Permissions | PDF file iconPDF (413 KB)  
    Freely Available from IEEE
  • Technical Program Committee chair message

    Publication Year: 2011 , Page(s): 2
    Save to Project icon | Request Permissions | PDF file iconPDF (408 KB)  
    Freely Available from IEEE
  • Sponsors and exhibitors

    Publication Year: 2011 , Page(s): 3 - 5
    Save to Project icon | Request Permissions | PDF file iconPDF (441 KB)  
    Freely Available from IEEE
  • About iWAT

    Publication Year: 2011 , Page(s): 6
    Save to Project icon | Request Permissions | PDF file iconPDF (394 KB)  
    Freely Available from IEEE
  • Keynote speakers

    Publication Year: 2011 , Page(s): 14 - 20
    Save to Project icon | Request Permissions | PDF file iconPDF (459 KB)  
    Freely Available from IEEE
  • Student poster paper contest

    Publication Year: 2011 , Page(s): 21 - 23
    Save to Project icon | Request Permissions | PDF file iconPDF (405 KB)  
    Freely Available from IEEE
  • International advisory committee

    Publication Year: 2011 , Page(s): 24
    Save to Project icon | Request Permissions | PDF file iconPDF (408 KB)  
    Freely Available from IEEE
  • Organizing committee

    Publication Year: 2011 , Page(s): 28
    Save to Project icon | Request Permissions | PDF file iconPDF (415 KB)  
    Freely Available from IEEE
  • Wideband curl antenna

    Publication Year: 2011 , Page(s): 110 - 111
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (71 KB) |  | HTML iconHTML  

    A conventional curl antenna is modified into a staircase curl antenna to realize a wideband axial ratio characteristic. It is found that the staircase curl has a dramatically wide bandwidth of approximately 50% for a 3 dB axial ratio criterion. It is also found that the VSWR exhibits values of less than 2 within this axial ratio bandwidth. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Antenna technologies from 435 MHz to 356 GHz for ESA's candidate Earth Explorer satellite missions

    Publication Year: 2011 , Page(s): 112 - 115
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (309 KB) |  | HTML iconHTML  

    As a result of down-selection after Phase 0 for the 7th Earth Explorer mission following the User Consultation Meeting held in Lisbon, Portugal in Jan 2009, three candidate missions were selected for further feasibility investigations (Phase A). Each of the candidate missions is now being defined in detail through two parallel and competing industrial system studies and supporting complementary science and technology studies, aiming to the final down-selection in 2012, followed by the mission implementation with a planned launch in the 2017 timeframe. The microwave payloads of those candidate missions cover the frequency range from 435 MHz to 356 GHz. The BIOMASS candidate mission aims to measure the global forest biomass at P-band (435 MHz) using the synthetic aperture radar (SAR) technique. Due to the long wavelength and large distance between the satellite and the Earth, a very large antenna aperture is required (50-100 m2). The CoReH2O candidate missions aims to quantitatively measure the global distribution of snow over land and sea ice at X-(9.6 GHz) and Ku-band (17.2 GHz) using the SAR technique. The PREMIER candidate mission, carrying an infrared limb sounder and a microwave limb sounder, the latter covering the frequency range of 313-356 GHz, aims to measure atmospheric composition in the upper Troposphere and lower Stratosphere. Three very distinct antenna technologies are required for enabling those satellite missions. This paper describes the different antenna concepts proposed and corresponding technology developments which are on-going. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Electromagnetic macromodels and Maxwellian circuits

    Publication Year: 2011 , Page(s): 116 - 119
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1131 KB) |  | HTML iconHTML  

    Discrete approximations and numerical solution of Maxwell's curl equations provide a foundation for the development of a variety of macro-models of electromagnetic passive devices, components, and sub-systems. In their majority, such macro-modeling is aimed at containing the cost of numerical computation by offering compact, computationally efficient models as alternatives to the computationally more expensive, detailed models of structures of multi-scale complexity. Preserving key physical attributes of the electromagnetic structure, as Maxwellian circuits attempt to do, is a highly desirable property of the macromodel, albeit not always possible. The aggressive pursuit of on-chip RF and mixed-signal functionality integration prompts us to consider electromagnetic macro-modeling from a different angle. More specifically, this paper entertains the possibility of using electromagnetic macro-models for the seamless insertion of spatially-accurate (distributed) models of integrated passives and their interactions in the nonlinear, high-frequency circuit simulators used for computer-aided analysis and design of on-chip RF and mixed-signal functional blocks. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Time-domain finite element analysis of electromagnetic radiation and scattering and microwave circuits

    Publication Year: 2011 , Page(s): 120 - 123
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (71 KB) |  | HTML iconHTML  

    In 1987, Cangellaris, Lin, and Mei proposed the time-domain finite element method as a promising numerical approach to simulating electromagnetic radiation and scattering phenomena. In this paper, we provide a brief overview of the recent progress in the development of the time-domain finite element method at the University of Illinois. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multilevel sparse approximate inverse preconditioning for solving dynamic integral equation by H-matrix method

    Publication Year: 2011 , Page(s): 124 - 127
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (162 KB) |  | HTML iconHTML  

    A novel sparse approximate inverse (SAI) preconditioner in multilevel fashion is proposed to accelerate the convergence rate of Krylov iterations for solving 3D electromagnetic scattering by integral equation. This multilevel formatted preconditioning is derived from the hierarchical data structure of hierarchical (H-) matrix, which overcomes the construction restrict of conventional SAI preconditioner combined with popular fast algorithms like multilevel fast multipole algorithm (MLFMA). Numerical experiments have demonstrated that this proposed preconditioner has a good property, can achieve fast convergence even for very complex structures. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • UWB antenna array

    Publication Year: 2011 , Page(s): 164 - 167
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (292 KB) |  | HTML iconHTML  

    This paper compares the performances of ultra wideband (UWB) arrays that use sinusoidal waveform for power pattern and ultra-short pulse waveform for energy pattern. In general, antenna arrays cannot have element spacing larger than one wavelength in any plane because the resulting grating lobes absorb much power, which will limit the bandwidth of antenna arrays. In particular, there are substantial differences between power pattern and energy pattern for UWB arrays. The grating lobes of UWB antenna array will not occur at the energy pattern even if the element spacing of array is larger than one wavelength. The limited antenna power patterns in frequency domain are used to describe the antenna performance. The energy pattern of antenna is the total response of power patterns in frequency domain. Energy pattern are quite similar to that of power pattern for narrow band antennas. It is enough to describe the antenna performance in narrow band communication systems. However, the limited antenna power patterns in frequency domain are not enough for UWB arrays in communication systems. Energy pattern will be easier to describe the energy pattern instead of power pattern for UWB arrays. In order to verify the theory of antenna pattern in energy, numerical simulations of UWB arrays with different element spacing are demonstrated the significance of these parameters and measured by the impulse time domain radar system. These results are of particular importance to the emerging technology of base band or time domain communications and remote sensing. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design of high performance sleeve dipole array antenna

    Publication Year: 2011 , Page(s): 168 - 171
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (198 KB) |  | HTML iconHTML  

    A 5-element planar dipole array antenna is analyzed and successfully implemented. The proposed antenna is designed for operation at 1.9 GHz band for basic station applications with S11<; -14 dB. The planar dipole array antenna comprises of a 1×5 dipole array and fed by a microstrip line. This structure is easily constructed by printing on both sides of a dielectric (FR4) substrate. The measured -14 dB return loss (VSWR 1.5:1) impedance bandwidth is around 7.0% (1.79-1.92 GHz). A reflector is put behind the dipole array to obtain directional radiation and high gain, and the measured maximum gain for operating frequencies across the 1.9 GHz band is about 6.9-8.6 dBi. The measured results of radiation efficiency, radiation pattern, antenna gain and return loss show that this dipole array is with a good performance. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Time-domain pulse-matched synthesis of ultra-wide band antennas

    Publication Year: 2011 , Page(s): 172 - 175
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (83 KB) |  | HTML iconHTML  

    Antenna synthesis can yield optimal radiating structures in terms of pattern diagram, gain, bandwidth or other figures of merit. Although the synthesis might be more difficult for continuous sources than for antenna arrays the resulting radiating structures are cheaper and easy to manufacture. In this paper, we propose a time-domain synthesis approach for ultra-wide band antennas. The method is based on a finite expansion of the antenna time-domain response. The synthesis is performed with regard to the resemblance between the time-domain radiated waveform and the waveform at the antenna input. The approach is validated by synthesizing a planar, ultra-wide band antenna designed for a particular waveform of excitation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Enhanced gain UWB slot antenna with multilayer Frequency-Selective Surface reflector

    Publication Year: 2011 , Page(s): 176 - 179
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (242 KB) |  | HTML iconHTML  

    Adequately design Frequency Selective Surfaces (FSSs) allow significant control of the phase of reflection and transmission characteristics over a wide frequency band. This property is used here to develop a multilayer FSS reflector enhancing the gain and radiation properties of antennas for ultra wideband applications. These kinds of reflectors make structures low profile by providing the flexibility in mounting them closer to antenna without disturbing the impedance bandwidth and providing a good gain control in the main beam direction. In order to design a suitable reflector dual layer FSS have been designed and employed with a slot antenna. FSS layer works from 4 GHz to 12 GHz, providing a linear transmission phase in the 133% bandwidth. Performance of the FSS is tested with UWB slot antenna and predicted results show significant gain enhancement while maintain the bandwidth of 140%. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Micro-antenna design for intra-cortical proximity communication

    Publication Year: 2011 , Page(s): 180 - 183
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (928 KB) |  | HTML iconHTML  

    This paper discusses the antenna design considerations for intra-cortical proximity communication. The performances of microstrip patch and monopole antenna systems at 60 GHz have been compared. The monopole antenna system can potentially bring down the power required for brain-machine interface technology to micro-watt level. The receiving power can be significantly improved and meet the sensitivity level of the conventional receivers for successful communications. Moreover, the wave propagates along the skull surface has been studied. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Miniaturized zeroth order resonance antenna over a reactive impedance surface

    Publication Year: 2011 , Page(s): 58 - 61
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (545 KB) |  | HTML iconHTML  

    A miniaturized zeroth order resonance (ZOR) antenna designed on a reactive impedance surface (RIS) is proposed and presented. It is essentially a composite right/left-handed (CRLH) structure which enables the miniaturization by pushing down the left-handed (LH) region. This is achieved by increasing the LH inductor using a shorted meander line. The RIS consists of two-dimensional periodic printed metallic patches. It is an inductive surface which can also miniaturize the antenna size and improve the radiation efficiency. The antenna radiates omni-directional waves in the horizontal plane. Simulated and measured results are provided, which show a good consistency. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Accurate analysis method for probe-fed cavity-backed patch array element

    Publication Year: 2011 , Page(s): 62 - 65
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (99 KB) |  | HTML iconHTML  

    An efficient modal method for the analysis and design of an array of probe-fed, cavity-backed patches with parasitic elements is presented. The probe feed can either be straight, stepped or L-shaped. The method described is very accurate resulting in a reliable design that works to the desired specifications the first time without any need for tuning, modification or successive iterations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Parallel higher-order FE-BI-MLFMA for 3D scattering

    Publication Year: 2011 , Page(s): 66 - 69
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (286 KB) |  | HTML iconHTML  

    The finite element-boundary integral-multilevel fast multipole algorithm (FE-BI-MLFMA) has shown to be very general and powerful for 3D scattering. This paper reports our major progress of FE-BI-MLFMA made over the past years. First, we report the study on different approaches of choosing surface in FE-BI-MLFMA. Second, we present the comparison of different algorithms of FE-BI-MLFMA. Third, we compare different higher-order basis functions in FE-BI-MLFMA. Forth, we present the state-of-the art of capability of our parallel FE-BI-MLFMA. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Application of the theory of Maxwellian Circuits to circular loop scatterers

    Publication Year: 2011 , Page(s): 128 - 131
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (79 KB) |  | HTML iconHTML  

    The conventional investigation on circular loop scatterer involves fairly complicated mathematical or numerical analyses. The formulation based on the theory of Maxwellian Circuits (MC) of circular loop is quite simple-it is a wave equation with constant complex parameters, which can even be solved analytically. The currents computed by MC are in excellent agreement with those computed by MoM. Analytic solutions of the wave equation are concise and suitable for fine tune in the design process and can also be extended to multi parallel circular loops. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A circularly polarized planar and slender antenna using helical element and back conductor

    Publication Year: 2011 , Page(s): 132 - 135
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (242 KB) |  | HTML iconHTML  

    A circularly polarized slender shaped helical antenna is presented. The helical antenna can generate circular polarization (CP) in the normal direction to the helical axias under a condition of structural parameters. However, when a planar and slender antenna shape is required, it may be difficult to satisfy the condition. In the proposed antenna, the ratio of the thickness : vertical : horizontal sides is approximately 1:2:8 which has been obtained generating circular polarization using a back conductor. The back conductor is installed at a close position behind the helical element using a capacitive feed structure in order to keep a low-profile structure. This antenna can be resonated at around 1 GHz with the size satisfying k0 a=0.35 (k0: wave mumber at the resonance frequency, a:radius of a hypothetical sphere circumferencing the antenna). Reasonable agreements have been obtained between simulated and measured results in S11, axial ratio, and radiation pattern. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.