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Åkerstedt, L., Blanco, D. & Jonsson, B. L. (2025). On Adaptive Frequency Sampling for Data-driven Model Order Reduction Applied to Antenna Responses. IEEE Transactions on Antennas and Propagation, 1-1
Open this publication in new window or tab >>On Adaptive Frequency Sampling for Data-driven Model Order Reduction Applied to Antenna Responses
2025 (English)In: IEEE Transactions on Antennas and Propagation, ISSN 0018-926X, E-ISSN 1558-2221, p. 1-1Article in journal (Refereed) In press
Abstract [en]

Frequency domain sweeps of array antennas are well-known to be time-intensive, and different surrogate models have been used to improve the performance. Data-driven model order reduction algorithms, such as the Loewner framework and vector fitting, can be integrated with adaptive frequency sampling algorithms, in an iterative scheme, to reduce the number of full-wave simulations required to accurately capture the requested frequency behavior of multiport array antennas. In this work, we propose two novel adaptive methods exploiting a block matrix function which is a key part of the Loewner framework generating system approach. The first algorithm leverages an inherent matrix parameter freedom in the block matrix function to identify frequency points with large errors, whereas the second utilizes the condition number of the block matrix function. The first method effectively provide a frequency domain error estimator, which is essential for improved performance. Numerical experiments on multiport array antenna S-parameters demonstrate the effectiveness of our proposed algorithms within the Loewner framework, where the proposed algorithms reach the smallest errors for the smallest number of frequency points chosen.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2025
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-364560 (URN)10.1109/tap.2025.3555890 (DOI)2-s2.0-105002451420 (Scopus ID)
Note

QC 20250617

Available from: 2025-06-16 Created: 2025-06-16 Last updated: 2025-06-17Bibliographically approved
Emadeddin, A. & Jonsson, B. L. (2024). A Fully Integrated Filtering Vivaldi Antenna With High Selectivity and Wide Out-of-Band Suppression. IEEE Access, 12, 2690-2700
Open this publication in new window or tab >>A Fully Integrated Filtering Vivaldi Antenna With High Selectivity and Wide Out-of-Band Suppression
2024 (English)In: IEEE Access, E-ISSN 2169-3536, Vol. 12, p. 2690-2700Article in journal (Refereed) Published
Abstract [en]

This paper introduces a novel filtering approach that employs integrated periodic structures with a conventional Vivaldi antenna to achieve a fully integrated bandpass filtering antenna. The approach results in a wide out-of-band suppression, high passband selectivity, adjustable operational bandwidth, and low insertion loss. The proposed filtering approach maintains the original size of the conventional Vivaldi antenna (base antenna) without requiring additional modifications. To validate the approach, we present two filtering Vivaldi antennas: filtering antenna I (center frequency: 18GHz, fractional bandwidth: 21%, insertion loss: 0.32dB) and filtering antenna II (center frequency: 6.5GHz, fractional bandwidth: 12%, insertion loss: 0.6dB). Their wide out-of-band gain suppression (typically >= 15dB) covers the conventional Vivaldi antenna's frequency range (4-24GHz). A prototype of the filtering antenna I is manufactured. Its measurement results validate the proposed approach and show good agreement with the simulated reflection coefficient, realized gain, and radiation patterns. The features of the proposed filtering antenna approach, make it suitable for various applications requiring efficient frequency filtering.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2024
Keywords
Filtering, Antennas, Vivaldi antennas, Bandwidth, Band-pass filters, Passband, Slot antennas, Filtering antenna, fully integrated antenna design, metasurface, out-of-band suppression, wideband antenna, filtenna
National Category
Signal Processing Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-342720 (URN)10.1109/ACCESS.2023.3348751 (DOI)001140279900001 ()2-s2.0-85181556812 (Scopus ID)
Note

QC 20240216

Available from: 2024-02-16 Created: 2024-02-16 Last updated: 2024-05-10Bibliographically approved
Frid, H., Hultin, H. & Jonsson, B. L. (2024). Convex Optimization of Wideband Monopulse Arrays. IEEE Transactions on Antennas and Propagation, 72(5), 4246-4257
Open this publication in new window or tab >>Convex Optimization of Wideband Monopulse Arrays
2024 (English)In: IEEE Transactions on Antennas and Propagation, ISSN 0018-926X, E-ISSN 1558-2221, Vol. 72, no 5, p. 4246-4257Article in journal (Refereed) Published
Abstract [en]

A convex optimization program is presented for wideband arrays. Constraints are imposed on the frequency variation of excitation coefficients to ensure that the optimal solution can be realized in a wideband active electronically scanned array (AESA). AESA implementation with true time delays (TTDs) and phase shifters are handled separately. We also discuss the general case of combining TTDs and phase shifters. Contrary to single-frequency optimization, the wideband optimization method presented here ensures that the computed excitation is optimal over a specified bandwidth. It is shown that there is a tradeoff between instantaneous bandwidth and sidelobe level. The proposed method works for both narrow and wideband arrays, as illustrated with examples. In addition to regular arrays, the method is also applicable to monopulse arrays. The optimization program is implemented in terms of embedded element patterns (EEPs) to account for and compensate for mutual coupling, radome, and platform effects.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2024
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-364555 (URN)10.1109/tap.2024.3378969 (DOI)001217104500051 ()2-s2.0-85189181479 (Scopus ID)
Funder
Swedish Foundation for Strategic Research, ID20-0004
Note

QC 20250617

Available from: 2025-06-16 Created: 2025-06-16 Last updated: 2025-06-17Bibliographically approved
Hultin, H., Frid, H., Jonsson, B. L. & Malmström, J. (2024). Investigation of Near-Field Contribution in Shooting and Bouncing Rays for Installed Antenna Performance on a Simple Platform. In: 18th European Conference on Antennas and Propagation, EuCAP 2024: . Paper presented at 18th European Conference on Antennas and Propagation, EuCAP 2024, Glasgow, United Kingdom of Great Britain and Northern Ireland, Mar 17 2024 - Mar 22 2024. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Investigation of Near-Field Contribution in Shooting and Bouncing Rays for Installed Antenna Performance on a Simple Platform
2024 (English)In: 18th European Conference on Antennas and Propagation, EuCAP 2024, Institute of Electrical and Electronics Engineers (IEEE) , 2024Conference paper, Published paper (Refereed)
Abstract [en]

The near-field contribution in the high-frequency method Shooting and Bouncing Rays (SBR) is investigated for installed antenna performance. Three SBR solvers, the in-house solver SIENT and two commercial solvers, are compared to a commercial full-wave solver. SIENT and one commercial solver have an option to disable near-field effects, which allows the strength of these effects to be investigated. The last solver also includes near-field effects. The results indicate an increase in accuracy when including near-field effects. The most notable difference in the far-field phase and the induced surface current are obtained for the in-house solver. Improvements for the surface current density is seen close to the antenna. On the tested platform, the difference in gain is not as notable but it is overestimated for both the in-house solver and the commercial solvers when excluding near-field terms.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2024
Keywords
Computational Electromagnetics (CEM), Installed Antenna Performance, Near-Field, Shooting and Bouncing Rays (SBR)
National Category
Fluid Mechanics
Identifiers
urn:nbn:se:kth:diva-346526 (URN)10.23919/EuCAP60739.2024.10500933 (DOI)001215536200030 ()2-s2.0-85192477107 (Scopus ID)
Conference
18th European Conference on Antennas and Propagation, EuCAP 2024, Glasgow, United Kingdom of Great Britain and Northern Ireland, Mar 17 2024 - Mar 22 2024
Note

QC 20240520

Part of ISBN 978-88-31299-09-1

Available from: 2024-05-16 Created: 2024-05-16 Last updated: 2025-02-09Bibliographically approved
Wang, L. & Jonsson, B. L. (2024). Millimeter-Wave Deep Integrated and Direct Matched Active Antenna for High Power Efficiency. In: 2024 IEEE 12th Asia-Pacific Conference on Antennas and Propagation, APCAP 2024 - Proceedings: . Paper presented at 12th IEEE Asia-Pacific Conference on Antennas and Propagation, APCAP 2024, Nanjing, China, Sep 22 2024 - Sep 25 2024. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Millimeter-Wave Deep Integrated and Direct Matched Active Antenna for High Power Efficiency
2024 (English)In: 2024 IEEE 12th Asia-Pacific Conference on Antennas and Propagation, APCAP 2024 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE) , 2024Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a novel active integrated antenna unit cell for millimeter-wave (mmW) active array designs. With the co-design of the electromagnetics and circuits, a 47% power added efficiency has been achieved over a 5 G band around 28 GHz. The direct matching network is simple and compact, which is easy to be allocated in the antenna unit cell. Moreover, the impedance bandwidth is also stable versus beam scanning in various directions. Hence, the investigated deep integration and direct matching technologies have significantly enhanced the system power efficiency, paving the way for high efficiency mmW communication systems.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2024
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-361972 (URN)10.1109/APCAP62011.2024.10881301 (DOI)2-s2.0-105000018638 (Scopus ID)
Conference
12th IEEE Asia-Pacific Conference on Antennas and Propagation, APCAP 2024, Nanjing, China, Sep 22 2024 - Sep 25 2024
Note

Part of ISBN 9798350351019

QC 20250409

Available from: 2025-04-03 Created: 2025-04-03 Last updated: 2025-04-09Bibliographically approved
Jonsson, B. L. (2024). Model Order Reduction for Parametric Dependence of Q-factor Bounds in IoT Applications. In: 18th European Conference on Antennas and Propagation, EuCAP 2024: . Paper presented at 18th European Conference on Antennas and Propagation, EuCAP 2024, Glasgow, United Kingdom of Great Britain and Northern Ireland, Mar 17 2024 - Mar 22 2024. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Model Order Reduction for Parametric Dependence of Q-factor Bounds in IoT Applications
2024 (English)In: 18th European Conference on Antennas and Propagation, EuCAP 2024, Institute of Electrical and Electronics Engineers (IEEE) , 2024Conference paper, Published paper (Refereed)
Abstract [en]

In Internet of Things (IoT) applications the antennas are often electrically small at their radiation frequency. This makes it hard to design antennas that meet desired bandwidth requirements. It is therefore interesting to consider the trade-off between antenna size and antenna position within the terminal with respect to its available bandwidth, as characterized by the Q-factor bound. To determine these quantities are associated with solving a non-trivial optimization problem. Recent development of model order reduction techniques can include parametric dependencies. Here we apply the data-driven Loewner framework to the Q-factors as a function of size and position parameters, to investigate how well these methods work for the Q-factor bounds in IoT applications. We show that the Loewner framework can deliver a reduced-order model of the bound. Properties of the reduced model can be used to indicate how well the reduced order interpolates the parametric dependence.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2024
Keywords
antennas, internet of things, Loewner framework, Model order reduction, Q-factor bounds
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-346515 (URN)10.23919/EuCAP60739.2024.10501045 (DOI)001215536200142 ()2-s2.0-85192443696 (Scopus ID)
Conference
18th European Conference on Antennas and Propagation, EuCAP 2024, Glasgow, United Kingdom of Great Britain and Northern Ireland, Mar 17 2024 - Mar 22 2024
Note

QC 20240521

Part of ISBN 978-883129909-1

Available from: 2024-05-16 Created: 2024-05-16 Last updated: 2024-09-27Bibliographically approved
Jonsson, B. L. & Hultin, H. (2024). On Efficient Representations of Frequency Dependent Far-Field Information for Array Antennas. In: 18th European Conference on Antennas and Propagation, EuCAP 2024: . Paper presented at 18th European Conference on Antennas and Propagation, EuCAP 2024, Glasgow, United Kingdom of Great Britain and Northern Ireland, Mar 17 2024 - Mar 22 2024. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>On Efficient Representations of Frequency Dependent Far-Field Information for Array Antennas
2024 (English)In: 18th European Conference on Antennas and Propagation, EuCAP 2024, Institute of Electrical and Electronics Engineers (IEEE) , 2024Conference paper, Published paper (Refereed)
Abstract [en]

This paper investigates the number of required data points to accurately represent the vector far-field information over the radiation sphere and its frequency variation for array antennas. The method needs to be explicit in terms of the excitation of the elements. We compare representations of far-field data on the sphere with two different approaches to spherical wave expansion representations and apply a data-driven model-order reduction to find a small-size representation. As is well known, a spherical wave expansion strongly reduces the number of required data points. Here, we show that accounting for the phase center of the elements further strongly reduces the number of required coefficients in the tested cases. The Loewner framework datadriven model-order reduction shrinks the required far-field data by an additional factor of 8-14 per mode coefficients, depending on the acceptable level of error. This reduction works well for the two investigated cases.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2024
Keywords
array antennas, far-fields, model order reduction, spherical vector modes
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-346532 (URN)10.23919/EuCAP60739.2024.10501604 (DOI)001215536203035 ()2-s2.0-85192478675 (Scopus ID)
Conference
18th European Conference on Antennas and Propagation, EuCAP 2024, Glasgow, United Kingdom of Great Britain and Northern Ireland, Mar 17 2024 - Mar 22 2024
Note

Part of ISBN: 978-88-31299-09-1, 979-8-3503-9443-6

QC 20240930

Available from: 2024-05-16 Created: 2024-05-16 Last updated: 2024-10-07Bibliographically approved
Emadeddin, A. & Jonsson, B. L. (2024). Wide-Scan Active Highly Integrated Phased Array Antenna for Tx/Rx Application at K-Band. In: 2024 18th European Conference on Antennas and Propagation (EuCAP): . Paper presented at 2024 18th European Conference on Antennas and Propagation (EuCAP), Glasgow, United Kingdom, Date of Conference: 17-22 March 2024. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Wide-Scan Active Highly Integrated Phased Array Antenna for Tx/Rx Application at K-Band
2024 (English)In: 2024 18th European Conference on Antennas and Propagation (EuCAP), Institute of Electrical and Electronics Engineers (IEEE) , 2024Conference paper, Published paper (Refereed)
Abstract [en]

A new wide-scan active direct-integrated phased array antenna (AIPAA), designed for Tx/Rx mm-Wave applications, is introduced in this paper. This novel AIPAA offers seamless switching performance between transmitting (Tx) and receiving (Rx) modes without the need for lossy intermediate RF components, such as RF switches, circulators, and duplexers. The unitcell of the AIPAA consists of three miniaturized tapered slot elements operating in the K-band frequency range. In the Tx mode, a GaN high electron mobility transistor serves as the power amplifier (PA), while in the Rx mode, a GaAs MMIC low noise amplifier (LNA) is employed. The unticell's center antenna element is reshaped to match closely to the optimal load impedance of the PA ( Zopt=6+j36Ω ) while the other elements are tuned to maintain a 50Ω input impedance suitable for the LNA. This direct integration approach enhances system efficiency and reduces the cost and size by eliminating the need for any intermediate impedance matching networks and RF switching components. The proposed Tx/Rx AIPAA achieves a matching at both the PA (optimum load) and LNA ( 50Ω ) ports with a 6% and 16% fractional bandwidth over ±50° scan coverage, respectively. The switching capability is incorporated by utilizing the ON/OFF modes of the PA and LNA DC-biasing. The proposed AIPAA's cell size is 9.2×6.5×1.8 mm3(0.67×0.5×0.13λ3) .

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2024
National Category
Communication Systems
Research subject
Electrical Engineering
Identifiers
urn:nbn:se:kth:diva-346264 (URN)10.23919/EuCAP60739.2024.10500931 (DOI)001215536200028 ()2-s2.0-85192462285 (Scopus ID)
Conference
2024 18th European Conference on Antennas and Propagation (EuCAP), Glasgow, United Kingdom, Date of Conference: 17-22 March 2024
Funder
Swedish Foundation for Strategic ResearchVinnova
Note

Part of ISBN 978-88-31299-09-1

QC 20240513

Available from: 2024-05-10 Created: 2024-05-10 Last updated: 2024-09-26Bibliographically approved
Emadeddin, A. & Jonsson, B. L. (2023). Coupling reduction in an active highly integrated Tx phased array antenna with scanning capability. AEU - International Journal of Electronics and Communications, 169, Article ID 154717.
Open this publication in new window or tab >>Coupling reduction in an active highly integrated Tx phased array antenna with scanning capability
2023 (English)In: AEU - International Journal of Electronics and Communications, ISSN 1434-8411, E-ISSN 1618-0399, Vol. 169, article id 154717Article in journal (Refereed) Published
Abstract [en]

This paper presents a novel method for analyzing and reducing the total coupled power in the Active Highly Integrated Phased Array Antennas (AIPAA), incorporating both the nonlinear impacts of the power amplifier (PA) transfer functions and the normalized scattering matrix. The proposed method introduces a new degree of freedom to reduce the coupling level utilizing two key factors: (i) the balance between the PAs’ transfer function gain and the coupled power difference to the PAs’ gate and drain/antenna ports, and (ii) the out-of-phase sum based on PAs’ transfer function phase response. The proposed method is theoretically demonstrated by accounting for all tones and also is subsequently simplified for the main tone. The method is practically validated by applying the method to a 1 × 5 AIPAA structure to reduce the total coupled power at its drain/antenna port. The results demonstrate a coupling reduction of −5 dB as an average with a maximum reduction of −20 dB, over a scan coverage of ±30∘ and 10% fractional bandwidth at 22 GHz for the center cell.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Active integrated phased array antennas, Beam steering, Coupling reduction, High integration, Mutual coupling
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Telecommunications
Identifiers
urn:nbn:se:kth:diva-331498 (URN)10.1016/j.aeue.2023.154717 (DOI)001021040700001 ()2-s2.0-85160725630 (Scopus ID)
Note

QC 20230710

Available from: 2023-07-10 Created: 2023-07-10 Last updated: 2024-05-10Bibliographically approved
Jonsson, B. L. & Ferrero, F. (2023). On Small Antennas with Circular Polarization, Bandwidth Estimates and Design Considerations. In: 17th European Conference on Antennas and Propagation, EUCAP: . Paper presented at 17th European Conference on Antennas and Propagation (EuCAP), Mars 26-31, 2023, Florence, Italy. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>On Small Antennas with Circular Polarization, Bandwidth Estimates and Design Considerations
2023 (English)In: 17th European Conference on Antennas and Propagation, EUCAP, Institute of Electrical and Electronics Engineers (IEEE), 2023Conference paper, Published paper (Refereed)
Abstract [en]

Circular polarization is an essential feature for small antennas designed to connect with satellite navigation systems. Here, a Q-factor optimization problem constrained with a circular polarization radiation requirement is formulated and solved. The constrained problem is shown to be solvable as fast as calculating the Q-factor bound without the constraint. Two antenna models are designed to assess the bounds. One aims for bandwidth, and the other for circular polarisation. The well-known relation between the Q-factor and the available bandwidth is used to evaluate the designs. The circularly polarised antenna is close to the bound and has a wide field of view. The Q-factor bound provides insight into desirable antenna positions on the small device.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2023
Series
Proceedings of the European Conference on Antennas and Propagation, ISSN 2164-3342
Keywords
Circular Polarization, Q-factor bounds, antenna, GNSS
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-335876 (URN)10.23919/EuCAP57121.2023.10133768 (DOI)001023316903142 ()2-s2.0-85162258109 (Scopus ID)
Conference
17th European Conference on Antennas and Propagation (EuCAP), Mars 26-31, 2023, Florence, Italy
Note

Part of ISBN 978-88-31299-07-7

QC 20230911

Available from: 2023-09-11 Created: 2023-09-11 Last updated: 2023-11-06Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0001-7269-5241

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