Searched for: subject%3A%22Antenna%255C+radiation%255C+patterns%22
(1 - 12 of 12)
document
Gaspar Silva, Jose Rui (author), Finkel, M. (author), Laauwen, Wouter M. (author), Yates, S.J.C. (author), Mirzaei, B. (author), Vercruyssen, N. (author), Young, Abram (author), Walker, Christopher (author), Gao, J.R. (author)
We have simulated and measured the beam properties of lens-antenna coupled hot electron bolometer mixers at a few supra-terahertz frequencies between 1.4 and 5.3 THz. The quasi-optical structures consist of an elliptical lens and a logarithmic spiral antenna. The model used for our simulations consists of a finite-element analysis to simulate...
journal article 2023
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Gasparsilva, Jose Rui (author), Finkel, M. (author), Laauwen, Wouter (author), Westerweld, Menno (author), More, Nikhil (author), Young, Abram (author), Kulesa, Craig (author), Walker, Christopher (author), Van der Tak, Floris (author), Gao, J.R. (author)
We report a high accuracy pointing technique for quasi-optical hot electron bolometer (HEB) mixers in focal-plane arrays designed to operate at 1.4, 1.9, and 4.7 THz. The high accuracy pointing is achieved by prealignment of a HEB chip to a lens, measuring the angular error of each mixer in an array assembly, and then realignment of the chip...
journal article 2022
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Puskely, J. (author), Mikulasek, Tomas (author), Aslan, Y. (author), Roederer, A.G. (author), Yarovoy, Alexander (author)
In this article, a concept of a phased antenna array based on substrate integrated waveguide (SIW) technology for 5G base stations is proposed. The array has a cosecant radiation pattern in the vertical plane for uniform illumination in a sector area. The array itself consists of 16 SIW traveling wave subarrays of 12 slot-coupled microstrip...
journal article 2022
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Wang, J. (author), Aubry, P.J. (author), Yarovoy, Alexander (author)
Ground penetrating radar imaging from the data acquired with arbitrarily oriented dipole-like antennas is considered. To take into account variations of antenna orientations resulting in spatial rotation of antenna radiation patterns and polarizations of transmitted fields, the full-wave method that accounts for the near-, intermediate-, and...
journal article 2018
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Syed, W.H. (author), Cavallo, D. (author), Neto, A. (author)
In this paper, we present an overview of our recent works on artificial dielectric layers (ADLs), used to enhance the radiation efficiency of planar printed antennas and arrays. The artificial material is realized by introducing planar sub-resonant metallic inclusions in a host material. This allows to enhance the permittivity of the host...
conference paper 2016
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Lager, I.E. (author), de Hoop, A.T. (author)
A full time-domain analysis is presented of the radiation properties of array antennas composed of identical, mutually translationally shifted, pulsed electric-current excited elements. An expression is derived for the radiated field in the farfield region, the parameters in which provide the basis for studying the pulsed-field beam-shaping and...
journal article 2015
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Cavallo, D. (author), Syed, W.H. (author), Neto, A. (author)
We present an analytical method to model artificial dielectric layers (ADLs) of finite height. Starting from the closed-form solution for the scattering from a single layer under plane wave illumination, the formulation is extended to the multi-layer case, by including the higher-order interaction between parallel layers in analytical form. The...
conference paper 2015
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Bentum, Mark J (author), Lager, I.E. (author), Bosma, S. (author), Bruinsma, W.P. (author), Hes, R.P. (author)
The impact of the fluctuations in the locations of elementary radiators on the radiation properties of three-dimensional (3D) array antennas is studied. The principal radiation features (sidelobes level, beam squint) are examined based on illustrative examples. Some atypical behaviours, that are specific to 3D arrays, are highlighted. The effect...
conference paper 2015
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Hortensius, H.L. (author), Öztürk, A. (author), Zeng, P. (author), Driessen, E.F.C. (author), Klapwijk, T.M. (author)
Antenna-coupled suspended single carbon nanotubes exposed to 108?GHz microwave radiation are shown to be selectively heated with respect to their metal contacts. This leads to an increase in the conductance as well as to the development of a power-dependent DC voltage. The increased conductance stems from the temperature dependence of tunneling...
journal article 2012
document
Pietersen, O.B.M. (author), Klinker, F. (author), Roefs, H.F.A. (author), Lucas, A.M.G.M. (author)
report 1984
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Pietersen, O.B.M. (author), Klinker, F. (author)
An analysis is given of possible interference induced by a position marker system, called RASP, into aircraft radio altimeters. The RASP system is used as a marker beacon in flight tests for trajectory measurements, and operates on 4.3 GHz. It is concluded that radio altimeters will not experience any harmful interference from a RASP transmitter.
report 1981
document
Schering, D.C. (author), Tellegen, H. (author)
Instationary methods in measuring radiation patterns of aircraft antennas are described.
report 1978
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