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Your search keyword '"Smolders, A. B."' showing total 131 results
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131 results on '"Smolders, A. B."'

1. Modern Antennas and Microwave Circuits -- A complete master-level course

Author

Smolders, A. B., Visser, H. J., and Johannsen, U.

Subjects
Electrical Engineering and Systems Science - Signal Processing, Physics - Applied Physics, Physics - Instrumentation and Detectors
Abstract

Modern antenna systems include passive antenna structures, passive microwave circuits and interconnections to electronics. Therefore, the antenna engineer should have a deep understanding of antenna theory and should be able to apply microwave engineering concepts. This textbook provides all relevant material for Master-level courses in the domain of antenna systems. The book includes comprehensive material on antennas and provides a solid introduction into microwave engineering, ranging from passive components to active circuits. We believe that this is the perfect mixture of know-how for a junior antenna expert. The theoretical material in this textbook can be supplemented by labs in which the students learn how to use state-of-the-art antenna and microwave design tools and test equipment, such as a vector network analyzer or a near-field scanner. Several chapters in this book can be used quite independent from each other. For example, chapter 6 can be used in a dedicated phased-array antenna course without the need to use Maxwell-based antenna theory from chapter 4. Similarly, chapter 3 on transmission lines and microwave circuits does not require deep back-ground knowledge in electromagnetics or antenna theory., Comment: Updated version January 2022, Improved formulation of equations in section 2.1. In addition, an old version of chapter 3 was included in the previous release

Published
2019

2. Waveguide Integration and Packaging of a Multichannel Power Amplifier in a SiGe BiCMOS Technology for mm-Wave Applications

Author

Kaul, Piyush, Aljarosha, Alhassan, Smolders, A. B., Matters-Kammerer, M. K., and Maaskant, Rob

Abstract

This article introduces the packaging and integration of a multichannel silicon-based power amplifier (PA) operating in the range of 70–74 GHz into a metal waveguide (WG) using a contactless IC-to-WG transition. This contactless transition facilitates the IC-WG connection and incorporates a spatial power combiner and an impedance matching network. This article outlines a comprehensive step-by-step design procedure for the PA and the WG. This procedure encompasses an IC-WG joint-design approach for designing input and output matching networks and spatial power splitter and combiner. Based on simulations and experimental results, this article discusses the need to include packaging design methodology in the overall design process, the effect of packaging technology, and their tolerances on prototype performance. The initial PA-WG prototype results show a measured saturated output power of ~0 dBm and a peak power gain of 11 dB at 72 GHz.

Published
2024
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4. Synthesis of Elliptically Shaped Aperiodic Antenna Arrays Subject to Complex Design Constraints.

Author

Geerarts, J. M. E., Theis, G., Smolders, A. B., and Caratelli, D.

Subjects
ANTENNA arrays, ANTENNAS (Electronics), PHYSICAL measurements
Abstract

State‐of‐the‐art conformal array pattern synthesis techniques typically suffer from a significant computational burden. This article builds upon the auxiliary array pattern synthesis technique, allowing the technique to work on elliptical contours. This deterministic method is both computationally efficient and capable of handling complex design cases with additional design constraints. In order to highlight the versatility and applicability, the method has been applied to an elliptical arc array comprised of Rampart antennas and an elliptical ring array using dipole elements. The results have been validated through full‐wave electromagnetic simulations, as well as physical measurements. Both arrays presented show good agreement with the proposed synthesis technique. Highlighting the ability to satisfy additional design constraints, such as enforcing a minimal element spacing or having a controlled beamformer‐network complexity. Plain Language Summary: This work presents a fast method to calculate the placement and excitation of antennas along an elliptical contour in order to achieve the desired radiation characteristics. The technique has been validated for an array featuring complex antenna elements and for an elliptical ring array. Key Points: The Auxiliary Array Pattern (AAP) formulation offers a deterministic and, thus, an inherently faster conformal array synthesis methodThe AAP formulation can be extended to support Elliptical contoursElliptical arrays with, for instance, Rampart or dipole elements can be quickly designed using the proposed synthesis method [ABSTRACT FROM AUTHOR]

Published
2024
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15. A Review of Antenna Array Technologies for Point-to-Point and Point-to-Multipoint Wireless Communications at Millimeter-Wave Frequencies

Author

Federico, G., Caratelli, D., Theis, G., and Smolders, A. B.

Subjects
Article Subject
Abstract

With the introduction of 5G communication systems operating in the mm-wave frequency range, new opportunities in terms of multimedia services and applications will become available. For this to happen, several technical challenges from an antenna standpoint need to be addressed. The achievements of high-gain characteristics and agile beamforming with wide-scan capabilities are the main targets of the ongoing research on mm-wave antenna arrays. In this paper, an up-to-date overview of antenna array technology for wireless communications at mm-wave frequencies is given. Particular focus is put on the review of the state-of-the art and most advanced antenna array concepts for point-to-point and point-to-multipoint radio links at said frequencies. Various figures of merit are assessed for a comprehensive analysis and bench marking of the technical solutions investigated in the presented survey.

Published
2021
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20. Cost-effective millimeter-wave measurement setup for narrowband path loss and angle-of-arrival measurements: uncertainty analysis and specular building reflection measurements.

Author

Schulpen, R., Bronckers, L. A., Smolders, A. B., and Johannsen, U.

Subjects
MONTE Carlo method, OCEAN waves, OFFSHORE structures, LABORATORY equipment & supplies
Abstract

A cost-effective millimeter-wave measurement setup for narrowband path loss and angle-of-arrival measurements is presented in this paper. The setup consists of ubiquitous radio-frequency lab equipment and additional low-cost components. An algorithm is developed, which improves the measurement accuracy and reduces the required measurement time. An uncertainty analysis is performed, including a noise analysis, amplifier linearity, antenna misalignment and general system impairments. A theoretical model of the received signal plus noise is developed, which is used in Monte Carlo simulations to show the impact of snapshot averaging on the uncertainty. The estimated combined uncertainty with a 95.45% confidence level is 1.1 dB at the maximum measurable path loss and 0.3 dB in the case of low path loss, where the uncertainty due to receiver noise is negligible. The measurement setup is used in outdoor specular building reflection measurements at 24.00–24.25 GHz. The measured single-building reflections show a 1–9 dB excess loss compared to the free-space path loss. The measured excess loss is 9–20 dB for double-building reflections. These results indicate that buildings could potentially be used as effective millimeter-wave specular reflectors to extend millimeter-wave coverage. [ABSTRACT FROM AUTHOR]

Published
2022
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26. Towards a generic model for MU-MIMO analysis including mutual coupling and multipath effects

Author

Amani, N., Henk Wymeersch, Johannsen, U., Smolders, A. B., Ivashina, M. V., Maaskant, R., Electromagnetics, Signal Processing Systems, Center for Wireless Technology Eindhoven, EM Antenna Systems Lab, and EM for Radio Science Lab

Subjects
Signal to noise ratio, Communication Systems, Wireless communication, Base station antenna, network theory, Signal Processing, Telecommunications, Mutual coupling, multi-user multiple-input multiple-output (MU-MIMO), Antenna arrays, Interference, Gratings, sparse array, Computer Science::Information Theory
Abstract

A network model which accounts for antenna mutual coupling and multipath effects in a wireless channel is proposed as a tool to qualitatively evaluate the performance of a multi-user multiple-input multiple-output (MU-MIMO) system. The system performance is assessed when a zero-forcing (ZF) beamformed conventional uniform linear array (ULA) and a sparse array are employed as one sector of a base station antenna (BSA) in a single-cell network. It is shown that highly correlated user equipments (UEs) in a line-of-sight (LOS) scenario can be decorrelated to some extents, by a scattering environment in a non-line-of-sight (NLOS) scenario. This occurs due to increase of the spatial variation by a multipath effect. Furthermore, in both environments a sparse array realized by an increased interelement spacing is also capable for correlation reduction among users due to the narrower beams.

Published
2019

27. Antenna-on-Chip radiation pattern characterization: analysis of different approaches

Author

Liu, Q., Johannsen, Ulf, van Beurden, Martijn C., Smolders, A. B., Electromagnetics, Electromagnetic and multi-physics modeling and computation Lab, Center for Wireless Technology Eindhoven, EM Antenna Systems Lab, and EM for Radio Science Lab

Subjects
Radiation pattern, bonding wires, diffraction, Antenna-on-chip, coupling, Wafer probe
Abstract

Millimeter-wave antenna measurements severely rely on the use of on-wafer probes. For an Antenna-on-chip (AoC), due to the tiny size of the chip (1~2 mm2), the radiation pattern will still be influenced when the probe tip is near the AoC under test (AUT). In addition, the edges of ground plane, the probe body, and the large holder will diffract the radiated fields and cause unexpected results. We have investigated how the probe and the test environment influence the radiation pattern by using a step-by-step approach to analyze the contribution each of the interfering sources. This analysis together with an experimental verification shows that an accurate radiation pattern of AoCs is difficult to characterize using existing probe-fed measurement strategies. To eliminate the large probe tip and body, a system-level approach could be used where the frequency generator is integrated on-chip. Another possible solution for an antenna designer is the bonding wire solution, which is low cost and easy to fabricate. The key rule of the design is that the location of the bond-wires needs to be perpendicular to the E-plane of the AUT.

Published
2019

28. 5G Millimeter-Wave NLOS Coverage Using Specular Building Reflections

Author

Schulpen, R., Bronckers, L. A., Smolders, A. B., Johannsen, U., Schulpen, R., Bronckers, L. A., Smolders, A. B., and Johannsen, U.

Abstract

Maximization of 5G millimeter-wave base station coverage and range is important to reduce the number of required base stations. Buildings could be used as reflectors to provide coverage in NLOS areas due to their high reflectivity at millimeter-waves. This paper presents the results of a measurement campaign investigating specular reflections from buildings at 24.00-24.25 GHz. The angle of minimum path loss for single-building reflections agrees well with the direction of the specular path. This agreement is less accurate in case of a double-building reflection, possibly due to obstructions in the specular path or multipath fading. In case of a single-building reflection, 1-9 dB excess loss compared to free-space path loss is measured. The excess loss is in the range of 9-20 dB for a double-building reflection. Although more research on this topic is required, these results are promising and indicate that buildings can be used as effective millimeter-wave reflectors.

Published
2020

37. On the use of focal-plane arrays in mm-wave 5G base stations

Author

Elsakka, A., Bressner, T. A.H., van den Biggelaar, A. J., Al-Rawi, A., Johannsen, U., Ivashina, M. V., Smolders, A. B., Elsakka, A., Bressner, T. A.H., van den Biggelaar, A. J., Al-Rawi, A., Johannsen, U., Ivashina, M. V., and Smolders, A. B.

Abstract

In mobile communications, the research and development for the fifth generation (5G) has gained significant interest in the recent years. The high data rate requirements for 5G introduce more challenges in terms of the system power consumption. Hence, considering the base station, a more efficient antenna system is necessary in order to provide higher signal to noise ratios to achieve the required data rates, while consuming the lowest possible amount of power. In this paper a phased array fed reflector is proposed as a solution for 5G base stations. The main idea is to use the high gain of a reflector antenna to achieve high effective isotropic radiated power (EIRP). That in turn allows the reduction of the number of feed array elements as well as the amount of supplied power. Consequently, the low cost silicon-based amplifiers can be utilized . The proposed solution includes our vision about some aspects of the antenna system regarding cell coverage, beamforming as well as antenna gain and EIRP. Finally, a system concept for the base station antenna subsystem is presented.

Published
2018

38. Optical Beamformer for K-band Smart Antenna Systems

Author

Trinidad, A. M., primary, Tessema, N., additional, Cao, Z., additional, van Zantvoort, J. H. C., additional, Dubok, A., additional, Al-Rawi, A. N. H., additional, Tangdiongga, E., additional, Smolders, A. B., additional, and Koonen, A. M. J., additional

Published
2018
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47. Double reflector configuration for optimal exposure of wideband focal plane arrays with optical beamforming

Author

Dubok, A., Al-Rawi, A., Tessema, N., Tangdiongga, E., Herben, M. H.A.J., Gerini, G., Smolders, A. B., Dubok, A., Al-Rawi, A., Tessema, N., Tangdiongga, E., Herben, M. H.A.J., Gerini, G., and Smolders, A. B.

Abstract

An optimized double-reflector antenna concept for a wideband focal plane array (FPA) configuration is presented for Ka-band applications with a limited scan range, e.g., ground terminals for satellite communication. The proposed reflector configuration allows maximizing the number of active array elements and minimizing the actual array size during scanning. In addition, the FPA configuration has been optimized for wideband optical true-time-delay beamforming, resulting in wideband operation from 20 to 40 GHz. Based on a minimum required 80% aperture efficiency at 30 GHz, the double-reflector concept allows expanding the illuminated region of the array by a factor of 60 compared to traditional prime-focus configurations. The proposed configuration also decreases the magnification factor M by a factor of 2.5 compared to the double-parabolic configuration for a ±1.5° scan range.

Published
2017

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