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Hu, Weidong (author), Xu, Zhihao (author), Jiang, Huanyu (author), Liu, Qingguo (author), Yao, Zhiyu (author), Tan, Zhen (author), Ligthart, L.P. (author)The terahertz frequency modulation continuous-wave (THz FMCW) imaging technology has been widely used in non-destructive testing applications. However, THz FMCW real-aperture radar usually has a small depth of field and poor lateral resolution, thus restricting the high-precision imaging application. This paper proposes a 150-220 GHz FMCW...journal article 2023
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Yao, Zhiyu (author), Hu, Weidong (author), Feng, Zhiyan (author), Zhang, Wenlong (author), Liu, Yang (author), Xu, Zhihao (author), Ligthart, L.P. (author)Passive multifrequency microwave sensors frequently struggle with difficulties of nonuniform spatial resolution among multiple channels. The raw measurements in the land-sea transition zone are seriously contaminated. Conventional analytical deconvolution techniques suffer from the tradeoff between spatial resolution enhancement and noise...journal article 2023
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Akbar, Fannush S. (author), Ligthart, L.P. (author), Hendrantoro, Gamantyo (author)A novel approach is proposed for building a planar array derived from linear arrays using a toolbox of different types of subarrays located parallel and perpendicular to the linear array axes. The array design assumes constant element patterns and focuses on rectangular array applications with one dimensional, wide-angular beam scanning....journal article 2021
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Akbar, F.S. (author), Ligthart, L.P. (author), Hendrantoro, Gamantyo (author), Lager, I.E. (author)The scanning performance of wide-angular scanning linear arrays is primarily degraded by the limited angular profile of the employed elements' patterns. This paper introduces an innovative strategy for compensating this degradation by using subarrays. Our design uses a uniform linear array with half-wavelength spaced elements, supplemented by...journal article 2019
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Tran, D. (author), Haider, N. (author), Valavan, S.E. (author), Lager, I.E. (author), Szilagyil, A. (author), Yarovyi, O. (author), Ligthart, L.P. (author)Ultra-wideband radio technology (UWB-RT) inherited a potential of extremely high rate of data communications, Claude Shannon discovered this in 1948 and derived the later-called-as Shannon-Hartley‘s channel capacity laws. This famous theoretical law however was not able to substantiate in practice until the development of the sampling...book chapter 2012
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Lian, X. (author), Nikookar, H. (author), Ligthart, L.P. (author)Cognitive radio (CR) is an intelligent radio system and is able to share the spectrum with licensed users (LU). By adopting adaptive beam forming techniques, CR can reuse the spectrum with LU via directing main beams towards CR users while displaying nulls towards LU. In this article, we present a new distributed beam forming (DB) technique, and...journal article 2012
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Hajian, M. (author), Kuijpers, B. (author), Buisman, K. (author), Akhnoukh, A. (author), Pelk, M. (author), De Vreede, L.C.N. (author), Zijdeveld, J. (author), Ligthart, L.P. (author), Spitas, C. (author)The design concept of passive and active reconfigurable reflectarray antennas has been proposed and tested. The antenna elements in the array are identical hollowed patches. In the first phase of study the slots are loaded with a SMD capacitor to set the required phase shift needed for array implementation. Simulations show promising results....journal article 2012
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Lu, H. (author), Xu, T. (author), Nikookar, H. (author), Ligthart, L.P. (author)In this paper, we investigate the diversity, capacity and complexity issues of cooperative Zero-Padding (ZP)-Orthogonal FrequencyDivisionMultiplexing (OFDM) communication. We consider cooperative ZP-OFDM communication over a multipath Rayleigh channel and with multiple Carrier Frequency Offsets (CFOs) existing at different relays. We use a...journal article 2011
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Lian, X. (author), Nikookar, H. (author), Ligthart, L.P. (author)In this paper, we introduce Adaptive Beamforming (AB) and Distributed Beamforming (DB) as two efficient techniques for IntelligentWiMAX (I-WiMAX). I-WiMAX is a new maritime communication system, consisting of Smart Radio (SR) principles and mobile WiMAX based on the IEEE 802.16e standard. Adopting AB, the same spectrum can accommodate more users...journal article 2011
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Tran, D. (author), Haider, N. (author), Aubry, P. (author), Szilagyi, A. (author), Lager, I.E. (author), Yarovoy, A. (author), Ligthart, L.P. (author)The number of topside shipboard antennas doubled every decade; in 1990s they were close to 200 and have no sight of stop growing (Tavik, 2005). The over-crowded present of such many topside antennas in a limited-space of littoral warfare ship has created/caused many critical, unavoidable problem like antenna blockage, electromagnetic...book chapter 2011
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Wang, Z. (author), Krasnov, O.A. (author), Babur, G.P. (author), Ligthart, L.P. (author), Van der Zwan, F. (author)This paper presents the development of a reconfigurable receiver to undertake challenging signal processing tasks for a novel polarimetric radar system. The field-programmable gate arrays (FPGAs)-based digital receiver samples incoming signals at intermediate frequency (IF) and processes signals digitally instead of using conventional analog...journal article 2011
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Babur, G. (author), Wang, Z. (author), Krasnov, O.A. (author), Ligthart, L.P. (author)This paper presents design and practical implementation of the method for cross-channel interference suppression in polarimetric LFM-CW radar with dual-orthogonal sounding signals. Simultaneously transmitted and received signals have limited orthogonality, what results in the interfering signals in the processing channels of the radar receiver....conference paper 2010
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Krasnov, O.A. (author), Babur, G.P. (author), Wang, Z. (author), Ligthart, L.P. (author), Van der Zwan, F. (author)The article describes the IRCTR PARSAX radar system, the S-band high-resolution Doppler polarimetric frequency modulated continuous wave (FM-CW) radar with dual-orthogonal sounding signals, which has the possibility to measure all elements of the radar target polarization scattering matrix simultaneously, in one sweep. The performance of such...journal article 2010
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Lager, I.E. (author), Trampuz, C. (author), Simeoni, M. (author), Ligthart, L.P. (author)An effective and robust strategy for concurrently designing the transmit and receive antennas of a frequency-modulated, continuos-wave radar is discussed. The aperture architecture is based on the use of non-periodic, interleaved sub-arrays. Deterministic element placement is employed for ensuring design efficiency. The procedure yields...journal article 2009
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Tanyer-Tigrek, F.M. (author), Tran, D.P. (author), Lager, I.E. (author), Ligthart, L.P. (author)An optimized coplanar waveguide fed quasimagnetic printed antenna for ultra wideband applications is described. A parameter study, motivated by a design procedure, allowed a substantial increase in the return-loss operational bandwidth. The numerically predicted performance was validated by means of physical measurements of fabricated samples....journal article 2009
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- Budiarjo, I. (author), Nikookar, H. (author), Ligthart, L.P. (author) journal article 2008
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Irahhauten, Z. (author), Dacuna, J. (author), Janssen, G.J.M. (author), Nikookar, H. (author), Yarovoy, A.G. (author), Ligthart, L.P. (author)Ultrawideband (UWB) technology is an attractive alternative for short-range applications, e.g., wireless personal area networks. In these applications, transmit and receive antennas are very close to each other and the far-field condition assumed in most of the link budget models may not be satisfied. Under near-field conditions, variations in...journal article 2008
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Budiarjo, I. (author), Nikookar, H. (author), Ligthart, L.P. (author)This article presents the performance comparison of TDCS and OFDM based cognitive radio for MIMO system using VBLAST receiver architecture to reconstruct the transmitted data. The interference avoidance performance in terms of BER and bitrate are improved by adding multiple antennas to the system and the use of V-BLAST technique at the receiver....journal article 2008
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Savelyev, T.G. (author), Yarovoy, A.G. (author), Ligthart, L.P. (author)This paper presents a 3-D imaging technique for an ultra-wideband (UWB) ground penetrating radar (GPR) with a single transmit antenna and a linear receive array. The video impulse GPR working in the frequency band of 0.3–3 GHz has been designed in IRCTR for landmine detection, i.e., for a near-field application. Installed on a vehicle it can...journal article 2008
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- Yarovoy, A.G. (author), Savelyev, T.G. (author), Aubry, P.J. (author), Ligthart, L.P. (author) conference paper 2007