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A Workshop on Advanced Antenna Technology, 2010 Indian Antenna Week

Date May 31 2010-June 4 2010

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Displaying Results 1 - 14 of 14
  • Identification of anomalies in paraboloid antenna reflector surface from its power radiation patterns

    Publication Year: 2010 , Page(s): 1 - 9
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3616 KB) |  | HTML iconHTML  

    Explosive growth of geo-stationary communication satellites has reduced the inter satellite space. This has resulted in very tight radiation specifications for earth station antennas. Antennas with surface flaws usually do not meet these specifications. This paper provides a method of identifying flaws on the surface of a parabolic reflector which when rectified would allow these antennas to meet radiation specifications without any expensive rebuilding or reassembly process. View full abstract»

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  • Antenna coupling for high power microwave tubes

    Publication Year: 2010 , Page(s): 1 - 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3057 KB) |  | HTML iconHTML  

    Microwave tubes are used for generation and amplification of high power (up to MW of pulsed/CW output power) and high frequency (0.3GHz to 1000GHz) electromagnetic waves. These tubes are in great demands for defense, communication, remote sensing, and for numerous industrial, scientific, and medical (ISM) applications. Input and output RF couplings in microwave tubes are very significant for efficient and reliable operation of these devices. Any coupler for a tube basically consists of four constituents: (i) probe, loop or slot for coupling e.m. waves from or into the RF structure, (ii) coaxial or waveguide impedance transformation section, (iii) glass or ceramic window to provide vacuum barrier and lossless transmission of rf power, and (iv) standard coaxial or waveguide output. Antenna probe is used to excite the waveguide output in case of coaxial transition. 3-dimensional e.m. field simulators like Ansoft HFSS and MWS-CST codes are used to achieve well matched and broadband design of the input and output couplers with the antenna probe. Standard mechanical codes like ANSYS, COSMOS are used to achieve thermal efficient and mechanically rugged design of the antenna coupling. Antenna couplings for some of the microwave tubes are presented in this paper. View full abstract»

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  • Concentric circular antenna array synthesis using Particle Swarm Optimization with Constriction Factor Approach

    Publication Year: 2010 , Page(s): 1 - 4
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1200 KB) |  | HTML iconHTML  

    In this paper, optimal array synthesis of three-ring concentric circular antenna arrays (CCAA) without and with central element feeding are reported. For each optimal synthesis, optimal current excitation weights and optimal radii of the rings are determined having the objective of maximum Sidelobe Level (SLL) reduction. The optimization technique adopted is Particle Swarm Optimization with Constriction Factor Approach (PSOCFA). The extensive computational results show that the CCAA having central element feeding yield much more reduction in SLL as compared to the same not having central element feeding. Moreover, the particular CCAA containing 4, 6 and 8 number of elements in three successive rings along with central element feeding yields grand minimum SLL (−36.00 dB). View full abstract»

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  • Comparison of hybrid-polarization with Quad-polarization schemes based on airborne SAR images

    Publication Year: 2010 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (718 KB) |  | HTML iconHTML  

    Now-a-days there has been growing interest in dual-pol systems, especially in hybrid-pol mode. In comparison to quad-pol system, the dual-pol system has the advantage of halved average transmitted power and double swath coverage. In this paper, we have discussed, in brief, the benefits of using hybrid-pol scheme. We also present comparisons of hybrid-pol and Quad-pol data based on the amount of information content. The airborne multi-polarization GTRI data set is used for demonstration. View full abstract»

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  • Diversity employment into target plus clutter SAR imaging using MIMO configuration

    Publication Year: 2010 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (434 KB) |  | HTML iconHTML  

    Multiple Input Multiple Output (MIMO) configurations in radar systems provide architectural and performance advantage over conventional monostatic and bistatic systems due to the implicit diversity characteristics of any MIMO system. Various authors are individually addressed either of these diversities. This work aims at parameterizing all the three, spatial, frequency and waveform diversities and hence designing a new MIMO SAR system for high resolution achievement. This system is designed taking into account both target and clutter, as clutter background pollutes the images substantially. The parameterizations and hence the constraints obtained on the system architecture and transmit signal properties ensure high resolution and better performance over conventional SAR imaging systems. View full abstract»

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  • Miniaturization of patch antennas using magneto-dielectric materials

    Publication Year: 2010 , Page(s): 1 - 4
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1036 KB) |  | HTML iconHTML  

    Miniaturization of antennas using novel magneto-dielectric substrates having permeability and permittivity values greater than one is proposed. The limitations of magneto-dielectric substrates at higher GHz frequencies and their suitable alternatives are discussed. The use of such substrates for the development of miniaturized antennas is validated by synthesis of a nickel cobalt zinc ferrite substrate with permittivity of 10.3 and permeability of 2.3 and loading it in an aperture coupled patch antenna. The loaded substrate shifts the resonance frequency of the base patch antenna to lower frequencies with improvement in return loss thus demonstrating the capability for miniaturization. View full abstract»

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  • Polymer ceramic composites for microwave substrate and antenna applications

    Publication Year: 2010 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (707 KB) |  | HTML iconHTML  

    The preparation and microwave dielectric properties Ca[(LiNb)0.8Ti0.2]O3-δ ceramic filled polymer composites for microwave substrate applications is discussed in this paper. The prediction of the dielectric properties of polymer-ceramic composites using different theoretical models is also discussed. A Coplanar Waveguide Monopole Antenna is designed and fabricated using epoxy-CLNT polymer-ceramic composite and compared its response with standard FR-4 epoxy. View full abstract»

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  • CPW- fed antenna with two rectangle slots for wideband application

    Publication Year: 2010 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2657 KB) |  | HTML iconHTML  

    This paper presents a CPW-fed antenna for wideband application. This Antenna satisfies the licensed frequency band of wireless communication and covers WLAN (5.15–5.85)GHz application for h= 0.5mm having return loss lower than −10 dB. This antenna is designed on a substrate with dielectric constant εr=4.4. With a size 27.5mm×28mm×0.5mm the antenna operates for wideband application. The effects of shape, length, size, and location of feeding point, substrate and their thickness have been evaluated. And obtained 2D radiation patterns with elevation, VSWR, Return loss, gain and antenna efficiency. The simulation results of this antenna are analyzed by using Method of Moment (MoM) from IE3D software. View full abstract»

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  • A compact novel CPW- fed reconfigurable antenna

    Publication Year: 2010 , Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2167 KB) |  | HTML iconHTML  

    This paper presents a compact novel CPW-fed reconfigurable antenna for two different applications. This Antenna satisfies the licensed frequency band for RFID and C-Band having return loss lower than −10 dB. The antenna is designed on a substrate with dielectric constant εr=4.4. With two different ON and OFF states the antenna can be used for different applications. The effects of shape, length, size, and location of feeding point, substrate and their thickness have been evaluated. And obtained 2D radiation patterns with elevation, VSWR, Return loss, gain and antenna efficiency. The simulation results of this antenna are analyzed by using Method of Moment (MoM) from IE3D software. View full abstract»

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  • A compact 3.5/5.5 GHz dual band-notched monopole antenna for application in UWB communication systems with defected ground structure

    Publication Year: 2010 , Page(s): 1 - 7
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1996 KB) |  | HTML iconHTML  

    A compact ultrawideband monopole antenna having dual band-notched characteristics with a defected ground structure (DGS) proposed. Two symmetrical L-shaped slots are created on the ground plane to generate the UWB characteristics in the proposed antenna. To generate the notch at 5.2/5.8 GHz band, a U-shaped slot is cut in the rectangular radiating element, which mitigate the potential interference with WLAN. To have another notch band simultaneously around 3.0/4.0 GHz, which is the operating band of WiMAX (3.3–3.6 GHz) and C-band (3.7–4.2 GHz), an inverted U-shaped element is printed on the opposite side of the substrate. By properly varying the dimensions of the U-shaped slot and the radiating element, not only two controllable notch resonances, but also a very wide bandwidth from 1.91 GHz to 3.91 GHz (152%) with two sharp notched bands covering all the 3.5/5.5 GHz WiMAX, 4 GHz C-band and 5.2/5.8 GHz WLAN, are achieved. The proposed antenna properly optimized and simulated providing broadband impedance matching, appropriate gain and stable radiation pattern characteristics. View full abstract»

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  • A compact CPW-fed monopole antenna with an U-shaped slot for 5 GHz/6 GHz band-notched ultrawideband applications

    Publication Year: 2010 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (504 KB) |  | HTML iconHTML  

    A planar ultrawideband (UWB) antenna with an U-shaped slot for a 5/6 GHz band notched characteristics is presented. The antenna is a planar structure and has a compact area of 25×25 mm2, which covers the frequency band from 3.1 GHz to 10.6 GHz (VSWR ≤ 2 ). The antenna has a circular slot cut in the ground plane and a circular patch is printed within that. A 50-Ω coplanar waveguide (CPW) transmission line is used to feed the printed circular metal patch. By removing a U-shaped slot from the circular patch, band rejected property in the WLAN band is obtained. The compact antenna has the promising performance including broadband impedance matching, consistent radiation pattern and stable gain View full abstract»

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  • Bandwidh enhancement with multi-band &multi-polarized rectangular microstrip patch antenna

    Publication Year: 2010 , Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1458 KB) |  | HTML iconHTML  

    This paper introduces a novel E-shape microstrip patch antenna for multi-band and multi-polarization facility using single layer structure. This E-shape antenna operates at three sub-bands, namely 5.75, 13.5 and 19.4 GHz with 20%, 70%, and 10% bandwidths respectively. By using only single patch a high impedance bandwidth is achieved. The proposed antenna has simple structure consisting E-shape on a rectangular patch dimension of the antenna come around 35mm×30mm×1.25mm and fed by 50 probe feed. The impedance matching and radiation characteristics of the designed structure are investigated by using MOM based IE3D. It has two ports excited with microstrip line feed mechanism. The simulation results show that the antenna offers excellent performance for UWB application ranging (5.35GHz to 6.52GHz) and (8.42GHz to 17.4) and (18.5GHz to 20.65GHz) simultaneously. View full abstract»

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  • Multi- band patch antenna on conjugate-omega slotted ground

    Publication Year: 2010 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1300 KB) |  | HTML iconHTML  

    A multi-band patch antenna on complementary conjugate omega ground is proposed. The proposed antenna utilizes complementary conjugate omega resonator (CCOR) in the ground plane altering the effective medium parameters of the substrate. The antenna features a multi frequency behavior (four operating bands) with similar gain. To characterize the performance of the CCOR loaded microstrip antenna, the metamaterial substrate has been modeled as an effective medium with extracted constitutive parameters. The embedded CCOR allows many resonant modes to be realized. View full abstract»

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  • A three element planner antenna array in Golden Ratio with 2∶1∶1 corporate feeding

    Publication Year: 2010 , Page(s): 1 - 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1207 KB) |  | HTML iconHTML  

    3 element planner antenna arrays with uniform and non-uniform spacing are compared. The non-uniform spacing uses the Golden Ratio. Simulated and experimental results are presented View full abstract»

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