Search Results - "de Villiers, D. I. L"

Primary beam effects of radio astronomy antennas – II. Modelling MeerKAT L-band beams by Asad, K M B, Girard, J N, de Villiers, M, Ansah-Narh, T, Iheanetu, K, Smirnov, O, Santos, M G, Lehmensiek, R, Jonas, J, de Villiers, D I L, Thorat, K, Hugo, B, Makhathini, S, Jozsa, G I G, Sirothia, S K

“…ABSTRACT After a decade of design and construction, South Africa’s SKA-MID precursor MeerKAT has begun its science operations. To make full use of the…”
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Design of a Ten-Way Conical Transmission Line Power Combiner by de Villiers, D.I.L., van der Walt, P.W., Meyer, P.

“…Axially symmetric power combiners, such as radial line and conical line combiners, are very effective in combining the output signals from a large number of…”
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The REACH radiometer for detecting the 21-cm hydrogen signal from redshift z ≈ 7.5–28 by de Lera Acedo, E., de Villiers, D. I. L., Razavi-Ghods, N., Handley, W., Fialkov, A., Magro, A., Anstey, D., Bevins, H. T. J., Chiello, R., Cumner, J., Josaitis, A. T., Roque, I. L. V., Sims, P. H., Scheutwinkel, K. H., Alexander, P., Bernardi, G., Carey, S., Cavillot, J., Croukamp, W., Ely, J. A., Gessey-Jones, T., Gueuning, Q., Hills, R., Kulkarni, G., Maiolino, R., Meerburg, P. D., Mittal, S., Pritchard, J. R., Puchwein, E., Saxena, A., Shen, E., Smirnov, O., Spinelli, M., Zarb-Adami, K.

“…Observations of the 21-cm line from primordial hydrogen promise to be one of the best tools to study the early epochs of the Universe: the dark ages, the…”
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The SARAO MeerKAT 1.3 GHz Galactic Plane Survey by Goedhart, S, Cotton, W D, Camilo, F, Thompson, M A, Umana, G, Bietenholz, M, Woudt, P A, Anderson, L D, Bordiu, C, Buckley, D A H, Buemi, C S, Bufano, F, Cavallaro, F, Chen, H, Chibueze, J O, Egbo, D, Frank, B S, Hoare, M G, Ingallinera, A, Irabor, T, Kraan-Korteweg, R C, Kurapati, S, Leto, P, Loru, S, Mutale, M, Obonyo, W O, Plavin, A, Rajohnson, S H A, Rigby, A, Riggi, S, Seidu, M, Serra, P, Smart, B M, Stappers, B W, Steyn, N, Surnis, M, Trigilio, C, Williams, G M, Abbott, T D, Adam, R M, Asad, K M B, Baloyi, T, Bauermeister, E F, Bennet, T G H, Bester, H, Botha, A G, Brederode, L R S, Buchner, S, Burger, J P, Cheetham, T, Cloete, K, de Villiers, M S, de Villiers, D I L, du Toit, L J, Esterhuyse, S W P, Fanaroff, B L, Fourie, D J, Gamatham, R R G, Gatsi, T G, Geyer, M, Gouws, M, Gumede, S C, Heywood, I, Hokwana, A, Hoosen, S W, Horn, D M, Horrell, L M G, Hugo, B V, Isaacson, A I, Józsa, G I G, Jonas, J L, Jordaan, J D B L, Joubert, A F, Julie, R P M, Kapp, F B, Kriek, N, Kriel, H, Krishnan, V K, Kusel, T W, Legodi, L S, Lehmensiek, R, Lord, R T, Macfarlane, P S, Magnus, L G, Magozore, C, Main, J P L, Malan, J A, Manley, J R, Marais, S J, Maree, M D J, Martens, A, Maruping, P, McAlpine, K, Merry, B C, Mgodeli, M, Millenaar, R P, Mokone, O J, Monama, T E, New, W S, Ngcebetsha, B

“…ABSTRACT We present the SARAO MeerKAT Galactic Plane Survey (SMGPS), a 1.3 GHz continuum survey of almost half of the Galactic Plane (251° ≤l ≤ 358° and 2° ≤l…”
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Author Correction: The REACH radiometer for detecting the 21-cm hydrogen signal from redshift z ≈ 7.5–28 by de Lera Acedo, E., de Villiers, D. I. L., Razavi-Ghods, N., Handley, W., Fialkov, A., Magro, A., Anstey, D., Bevins, H. T. J., Chiello, R., Cumner, J., Josaitis, A. T., Roque, I. L. V., Sims, P. H., Scheutwinkel, K. H., Alexander, P., Bernardi, G., Carey, S., Cavillot, J., Croukamp, W., Ely, J. A., Gessey-Jones, T., Gueuning, Q., Hills, R., Kulkarni, G., Maiolino, R., Meerburg, P. D., Mittal, S., Pritchard, J. R., Puchwein, E., Saxena, A., Shen, E., Smirnov, O., Spinelli, M., Zarb-Adami, K.

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Accurate Beam Prediction Through Characteristic Basis Function Patterns for the MeerKAT/SKA Radio Telescope Antenna by Young, A., Maaskant, R., Ivashina, M. V., de Villiers, Dirk I. L., Davidson, D. B.

“…A novel beam expansion method is presented that requires employing only a few Characteristic Basis Function Patterns (CBFPs) for the accurate prediction of…”
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The 1.28 GHz MeerKAT Galactic Center Mosaic by Heywood, I., Rammala, I., Camilo, F., Cotton, W. D., Yusef-Zadeh, F., Abbott, T. D., Adam, R. M., Adams, G., Aldera, M. A., Asad, K. M. B., Bauermeister, E. F., Bennett, T. G. H., Bester, H. L., Bode, W. A., Botha, D. H., Botha, A. G., Brederode, L. R. S., Buchner, S., Burger, J. P., Cheetham, T., de Villiers, D. I. L., Dikgale-Mahlakoana, M. A., du Toit, L. J., Esterhuyse, S. W. P., Fanaroff, B. L., February, S., Frank, B. S., Gamatham, R. R. G., Geyer, M., Goedhart, S., Gouws, M., Gumede, S. C., Hlakola, M. J., Hokwana, A., Hoosen, S. W., Horrell, J. M. G., Hugo, B., Isaacson, A. I., Józsa, G. I. G., Jonas, J. L., Joubert, A. F., Kapp, F. B., Kenyon, J. S., Kriek, N., Kriel, H., Krishnan, V. K., Liebenberg, D., Lord, R. T., Lunsky, B. M., Madisa, K., Mahgoub, O., Makhaba, A., Makhathini, S., Malan, J. A., Manley, J. R., Marais, S. J., Mauch, T., Merry, B. C., Millenaar, R. P., Mnyandu, N., Mokone, O. J., Monama, T. E., Mphego, M. C., New, W. S., Ngcebetsha, B., Ngoasheng, K. J., Ockards, M. T., Oozeer, N., Otto, A. J., Passmoor, S. S., Patel, A. A., Peens-Hough, A., Perkins, S. J., Ramaila, A. J. T., Ramanujam, N. M. R., Ramudzuli, Z. R., Robyntjies, A., Sambu, N., Schollar, C. T. G., Schwardt, L. C., Schwartz, R. L., Serylak, M., Siebrits, R., Sirothia, S. K., Smirnov, O. M., Sofeya, L., Taljaard, B., Tasse, C., Tiplady, A. J., Twum, S. N., van der Byl, A., van der Merwe, C., Van Tonder, V., Van Wyk, R., Venter, A. J., Venter, M., Wallace, B. H., Welz, M. G., Williams, L. P., Xaia, B.

“…Abstract The inner ∼200 pc region of the Galaxy contains a 4 million M ⊙ supermassive black hole (SMBH), significant quantities of molecular gas, and star…”
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The REACH radiometer for detecting the 21-cm hydrogen signal from redshift 7.5 to 28 by Acedo, E. de Lera, de Villiers, D. I. L, Razavi-Ghods, N, Handley, W, Fialkov, A, Magro, A, Anstey, D, Bevins, H. T. J, Chiello, R, Cumner, J, Josaitis, A. T, Roque, I. L. V, Sims, P. H, Scheutwinkel, K. H, Alexander, P, Bernardi, G, Carey, S, Cavillot, J, Croukamp, W, Ely, J. A, Gessey-Jones, T, Gueuning, Q, Hills, R, Kulkarni, G, Maiolino, R, Meerburg, P. D, Mittal, S, Pritchard, J. R, Puchwein, E, Saxena, A, Shen, E, Smirnov, O, Spinelli, M, Zarb-Adami, K

“…Nature Astronomy 6, p 984 998, 2022 Observations of the 21-cm line from primordial hydrogen promise to be one of the best tools to study the early epochs of…”
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Primary beam effects of radio astronomy antennas -- II. Modelling the MeerKAT L-band beam by Asad, K. M. B, Girard, J. N, de Villers, M, Ansah-Narh, T, Iheanetu, K, Smirnov, O, Santos, M. G, Lehmensiek, R, Jonas, J, de Villiers, D. I. L, Thorat, K, Hugo, B, Makhathini, S, Jozsa, G. I. G, Sirothia, S. K

“…After a decade of design and construction, South Africa's SKA-MID precursor MeerKAT has begun its science operations. To make full use of the widefield…”
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Efficient Analysis of Large Aperiodic Antenna Arrays Using the Domain Green's Function Method by Ludick, Daniel J., Maaskant, Rob, Davidson, David B., Jakobus, Ulrich, Mittra, Raj, de Villiers, Dirk

“…An efficient method-of-moments (MoM) based domain decomposition technique, viz., the domain Green's function method (DGFM), is presented for analyzing large…”
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Prediction of Aperture Efficiency Ripple in Clear Aperture Offset Gregorian Antennas by de Villiers, Dirk I. L.

“…Electrically small clear aperture dual offset reflector systems often exhibit a directivity ripple over frequency due to the interference of the diffracted…”
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Constant Radiation Characteristics for Log-Periodic Dipole Array Antennas by Lehmensiek, Robert, de Villiers, Dirk I. L.

“…Given the correct terminal voltages on each element of a log-periodic dipole array constant radiation characteristics can be achieved for an omni-directional…”
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Modeling of the Radiation Pattern of a Pair of Thin Circular-Arc Dipoles Over an Infinite Ground Plane by de Villiers, Dirk I. L., Lehmensiek, Robert

“…This communication presents a model of the radiation pattern of two circular-arc dipoles above an infinite perfectly electrically conducting ground plane. A…”
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A comparison of full pattern and response feature based modeling of antenna radiation patterns by de Villiers, D. I. L.

“…This paper compares the interpolation based modeling of antenna radiation pattern response features when the models are built directly on the response feature…”
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Probe Positioning Error Sensitivity Analysis for Planar Near-field Antenna Measurements by Kriel, S. G. H., de Villiers, D. I. L.

“…Unmanned aerial vehicle based field measurements have been proposed as a possible solution to provide calibration data for large ground based radio telescope…”
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Receiver design for the REACH global 21-cm signal experiment by Razavi-Ghods, Nima, Roque, Ian L. V, Carey, Steven H, Ely, John A, Handley, Will, Magro, Alessio, Chiello, Riccardo, Huang, Tian, Alexander, P, Anstey, D, Bernardi, G, Bevins, H. T. J, Cavillot, J, Croukamp, W, Cumner, J, Acedo, E. de Lera, de Villiers, D. I. L, Fialkov, A, Gessey-Jones, T, Gueuning, Q, Josaitis, A. T, Kulkarni, G, Leeney, S. A. K, Maiolino, R, Meerburg, P. D, Mittal, S, Pagano, M, Pegwal, S, Pieterse, C, Pritchard, J. R, Saxena, A, Scheutwinkel, K. H, Scott, P, Shen, E, Sims, P. H, Smirnov, O, Spinelli, M, Zarb-Adami, K

“…We detail the the REACH radiometric system designed to enable measurements of the 21-cm neutral hydrogen line. Included is the radiometer architecture and…”
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Ultra-wideband Planar Marchand Balun Design for the Pyramidal Sinuous Antenna by Johnston, M., Van Niekerk, C., de Villiers, D.I.L

“…This article presents the design of an ultra-wideband planar Marchand balun for the pyramidal sinuous antenna. Ground plane slots, placed beneath the…”
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The SARAO MeerKAT 1.3 GHz Galactic Plane Survey by Goedhart, S, Cotton, W. D, Camilo, F, Thompson, M. A, Bietenholz, M, Woudt, P. A, Bordiu, C, Buemi, C. S, Bufano, F, Cavallaro, F, Chen, H, Chibueze, J. O, Egbo, D, Frank, B. S, Hoare, M. G, Ingallinera, A, Irabor, T, Kurapati, S, Leto, P, Loru, S, Mutale, M, Plavin, A, Rajohnson, S. H. A, Rigby, A, Riggi, S, Seidu, M, Serra, P, Smart, B. M, Stappers, B. W, Steyn, N, Trigilio, C, Abbott, T. D, Adam, R. M, Baloyi, T, Bauermeister, E. F, Bennet, T. G. H, Bester, H, Botha, A. G, Buchner, S, Burger, J. P, Cheetham, T, Cloete, K, de Villiers, M. S, de Villiers, D. I. L, Toit, L. J. du, Fanaroff, B. L, Gatsi, T. G, Gouws, M, Gumede, S. C, Heywood, I, Hoosen, S. W, Horn, D. M, Horrell, L. M. G, Hugo, B. V, Isaacson, A. I, Józsa, G. I. G, Jonas, J. L, Jordaan, J. D. B. L, Joubert, A. F, Kriek, N, Kriel, H, Krishnan, V. K, Legodi, L. S, Lord, R. T, Macfarlane, P. S, Magnus, L. G, Magozore, C, Main, J. P. L, Manley, J. R, Maree, M. D. J, Martens, A, McAlpine, K, Merry, B. C, Millenaar, R. P, Mokone, O. J, Monama, T. E, New, W. S, Ngcebetsha, B, Ngoasheng, K. J, Nicolson, G. D, Oozeer, N, Passmoor, S. S, Patel, A. A, Peens-Hough, A, Perkins, S. J, Ramaila, A. J. T, Ratcliffe, S. M, Richter, L. L, Sambu, N, Schollar, C. T. G, Schwardt, L. C, Schwartz, R. L, Serylak, M, Siebrits, R, Sirothia, S. K, Smirnov, O. M, van der Byl, A, Van Tonder, V, Venter, A. J, Williams, L. P

“…We present the SARAO MeerKAT Galactic Plane Survey (SMGPS), a 1.3 GHz continuum survey of almost half of the Galactic Plane (251\deg $\le l \le$ 358\deg and…”
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Surrogate-based antenna element optimization for regularly spaced aperture arrays by Klopper, B., De Villiers, D. I. L.

“…A surrogate-based modelling study of an infinite, regular aperture array of bowtie antenna elements is presented. The sensitivity per element is predicted…”
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Coaxial Marchand Balun - Design and Fabrication by Johnston, M., Van Niekerk, C., de Villiers, D.I.L

“…This article presents the design of an ultra-wideband coaxial Marchand balun for the pyramidal sinuous antenna. The focus of the design is related to the…”
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