| 1. |
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| 2. |
- Anjos, Eduardo V.P., et al.
(author)
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FORMAT: A Reconfigurable Tile-Based Antenna Array System for 5G and 6G Millimeter-Wave Testbeds
- 2022
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In: IEEE Systems Journal. - 1932-8184 .- 1937-9234. ; In Press
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Journal article (peer-reviewed)abstract
- This article introduces the FORMAT array, a reconfigurable millimeter-wave antenna array platform based on antenna tiles. FORMAT stands for Flexible Organization and Reconfiguration of Millimeter-wave Antenna Tiles, which is a unique hardware solution aiming to implement and demonstrate a variety of antenna array concepts, as well as different array architectures and configurations from the same basic module, providing even benchmark between different solutions and thus valuable insights into fifth-generation (5G) and beyond-5G antenna systems. The combination of a minimum-sized tile with 3D-printed frame parts enables antenna arrays of a variety of sizes, allows multiple beamforming architectures, and a range of different antenna element positioning in the array. The hardware implementation is thoroughly described, with a few different array assemblies being manufactured and measured, validating their antenna performance with over-the-air measurements. Finally, using FORMAT hardware as both base station and user equipment, a 5-m wireless communication link was set up, achieving 4.8 Gbps downlink speed with QAM64 modulation.
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| 3. |
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| 4. |
- Fager, Christian, 1974, et al.
(author)
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IC Design Aspects for 5G mm-Wave Systems
- 2020
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In: 2020 50TH EUROPEAN MICROWAVE CONFERENCE (EUMC). - 2325-0305. - 9782874870590 ; , s. 870-871
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Conference paper (other academic/artistic)
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| 5. |
- Marinovic, Tomislav, et al.
(author)
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Effect of antenna array element separation on capacity of MIMO systems including mutual coupling
- 2019
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In: 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, APSURSI 2019 - Proceedings. ; , s. 415-416
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Conference paper (peer-reviewed)abstract
- In this paper, we study the effect of element separation in a base station array (BSA) on the downlink line-of-sight achievable sum-rate of MIMO systems in the presence of mutual coupling at the BSA. The channel matrix H is modeled using the embedded field patterns of the BSA and is used to analyze the outage performance for two single-element user equipments assuming no inter-user coupling.
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| 6. |
- Radiom, Soheil, et al.
(author)
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Far-Field On-Chip Antennas Monolithically Integrated in a Wireless-Powered 5.8-GHz Downlink/UWB Uplink RFID Tag in 0.18-mu m Standard CMOS
- 2010
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In: IEEE Journal of Solid-State Circuits. - 0018-9200 .- 1558-173X. ; 45:9, s. 1746-1758
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Journal article (peer-reviewed)abstract
- This paper discusses two antennas monolithically integrated on-chip to be used respectively for wireless powering and UWB transmission of a tag designed and fabricated in 0.18-mu m CMOS technology. A multiturn loop-dipole structure with inductive and resistive stubs is chosen for both antennas. Using these on-chip antennas, the chip employs asymmetric communication links: at downlink, the tag captures the required supply wirelessly from the received RF signal transmitted by a reader and, for the uplink, ultra-wideband impulse-radio (UWB-IR), in the 3.1-10.6-GHz band, is employed instead of backscattering to achieve extremely low power and a high data rate up to 1 Mb/s. At downlink with the on-chip power-scavenging antenna and power-management unit circuitry properly designed, 7.5-cm powering distance has been achieved, which is a huge improvement in terms of operation distance compared with other reported tags with on-chip antenna. Also, 7-cm operating distance is achieved with the implemented on-chip UWB antenna. The tag can be powered up at all the three ISM bands of 915 MHz and 2.45 GHz, with off-chip antennas, and 5.8 GHz with the integrated on-chip antenna. The tag receives its clock and the commands wirelessly through the modulated RF powering-up signal. Measurement results show that the tag can operate up to 1 Mb/s data rate with a minimum input power of -19.41 dBm at 915-MHz band, corresponding to 15.7 m of operation range with an off-chip 0-dB gain antenna. This is a great improvement compared with conventional passive RFIDs in term of data rate and operation distance. The power consumption of the chip is measured to be just 16.6 mu W at the clock frequency of 10 MHz at 1.2-V supply. In addition, in this paper, for the first time, the radiation pattern of an on-chip antenna at such a frequency is measured. The measurement shows that the antenna has an almost omnidirectional radiation pattern so that the chip's performance is less direction-dependent.
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| 7. |
- Aliakbari Abar, Hanieh, et al.
(author)
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79 GHz multilayer series-fed patch antenna array with stacked micro-via loading
- 2022
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In: IEEE Antennas and Wireless Propagation Letters. - 1548-5757. ; 21:10, s. 1990-1994
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Journal article (peer-reviewed)abstract
- A wideband compact series-fed patch subarray is proposed for 79 GHz multiple-input multiple-output (MIMO) radar. The proposed subarray is, for the first time, loaded with stacked micro-vias (SMVs). Two sets of patches in the subarray are fed 180-degrees out-of-phase. A low-cost, high-resolution multilayer PCB technology, called “Any-Layer PCB”, is used to implement the SMVs, which cannot be done by standard HDI PCB technology. Moreover, the technology supports small SMVs on different layers, hence thick machine-drilled vias can be avoided. For comparison, a series-fed patch subarray with no SMV loading is designed. It is shown that SMV loading facilitates a larger overlap of the impedance and gain bandwidths, leading to a larger operating bandwidth. The measured 10 dB impedance and 3 dB gain bandwidths are 15% and 9.6%, respectively. The sidelobe suppression is above 12.9 dB, and the maximum array gain is 12.67 dBi at 79.1 GHz. This subarray is suitable for MIMO radar, as its width is around 1/2-wavelength and the SMVs around it mitigate the crosstalk between the transmitting and receiving arrays.
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| 8. |
- Aliakbari Abar, Hanieh, et al.
(author)
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Wideband SIW-based Low-cost Multi-layer Slot Antenna Array for E-Band Applications
- 2019
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In: IEEE Transactions on Components, Packaging and Manufacturing Technology. - 2156-3950. ; , s. 1-1
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Journal article (peer-reviewed)abstract
- This paper proposes a substrate integrated waveguide (SIW) slot antenna array for wideband gigabyte mobile radio application in E-band. The wideband unit cell design is based on simultaneous feeding of 4-element radiation slots with a higher order cavity mode directly excited by a simple slot aperture fed by a microstrip fork-like tuning stub. Employing the higher order mode along with the slot aperture facilitate low loss, simple feeding network and lower sensitivity to fabrication errors. To cancel the beam tilt versus frequency, the higher order mode unit cell is used in a 2 × 2 array along with a differential feeding structure. The array was designed and taped out using a new high-resolution multi-layer PCB technology and characterized by using the constructed millimeter wave measurement setup at KU Leuven /IMEC. This technology provides the possibility to stack micro-vias in PCB boards and reduce fabrication cost compared to other multi-layer technologies in mm-wave bands. The proposed array in 2 × 2 array configuration has a measured bandwidth of 11.4 GHz (16%), a total efficiency of 69%, a realized gain of 12 dBi at 72 GHz and a 3-dB gain bandwidth that covers the entire impedance bandwidth. In comparison to existing E-band SIW slot arrays (compensating for array sizes), the proposed design achieves similar or better performance in bandwidth but with lower cost, lower sensitivity to fabrication tolerances and higher total efficiency.
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| 9. |
- Anjos, Eduardo V. P., et al.
(author)
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A 5G Active Antenna Tile and its Characterization in a Reverberation Chamber
- 2020
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In: 2020 14TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP 2020). - 2164-3342.
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Conference paper (peer-reviewed)abstract
- This work presents a 5G active antenna tile system, enabling the flexible construction of hybrid beamforming (HBF) arrays. The proposed tile was fabricated using a standard PCB manufacturing process and to validate its performance. Using a Reverberation Chamber (RC), the tile was measured in both Tx and Rx mode, achieving up to 1.6 GHz in bandwidth around a central frequency of 27.8 GHz.
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| 10. |
- Baghaei Nejad, Majid, et al.
(author)
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Impulse UWB Antenna size reduction due to Transmitter-Antenna Co-design
- 2008
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In: 2008 IEEE INTERNATIONAL CONFERENCE ON ULTRA-WIDEBAND. - New York : IEEE. - 9781424422166 ; , s. 37-40
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Conference paper (peer-reviewed)abstract
- In this paper, the benefit of a co-design between a modified small-size Printed Tapered Monopole Antenna (PTMA) and an Impulse Ultra Wideband transmitter Is Investigated for the 3.1-10.6GHz bond. A comparison is given between a 50 Omega design and a co-designed version. The simulation results show that with the co-design method the tunable UWB transmitter can reach the bandwidth regulation for a much smaller antenna.
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| 11. |
- Ebrahimizadeh, Javad, et al.
(author)
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RCS-Based 3D Millimeter-Wave Channel Modeling Using Quasi-Deterministic Ray Tracing
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In: IEEE Transactions on Antennas and Propagation. - 0018-926X.
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Journal article (peer-reviewed)abstract
- This paper introduces a low-complexity ultra-wideband quasi-deterministic ray tracing (QD-RT) method for statistical analysis of wireless channels. This model uses a statistical distribution to model the bistatic radar-cross-section (RCS) of irregular objects such as cars and pedestrians, instead of a deterministic propagation model, i.e., applying the exact values of bistatic RCSs. It is shown that the quasi-deterministic propagation model benefits from a low complexity compared with a deterministic model while keeping the accuracy. The proposed QD-RT method is applied in a realistic street canyon scenario in the millimeter wave frequency band, and the performance of the QD-RT method is verified by the deterministic propagation method, where the second-order statistics including root-mean-square (RMS) delay spread and angular spread and the first-order statistic transfer function yield good agreements. Finally, the application of the QD-RT in stochastic channel modeling is demonstrated by developing a 3GPP-like statistical channel model for street canyon scenarios.
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| 12. |
- Kupresak, Mario, et al.
(author)
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Hydrodynamic approach for deep-nanometer scale topologies: Analysis of metallic shell
- 2021
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In: 2020 International Symposium on Antennas and Propagation, ISAP 2020. ; , s. 269-270
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Conference paper (peer-reviewed)abstract
- In order to describe light-matter interaction at deep-nanometer scale, which is governed by nonclassical phenomena, a semiclassical hydrodynamic model with additional boundary conditions has been introduced. This model investigates the motion of the charged gas in metals, characterized by nonlocal material parameters. Based on different treatments of the nonlocality, several hydrodynamic models have been proposed. This work employs the hard wall hydrodynamic model (HW-HDM) and the quantum hydrodynamic model (Q-HDM). The study is performed for the mode structure (natural modes) of a spherical metallic nanoshell, supplemented by the plane wave response of the system. It is shown that the main transverse resonances of HW-HDM and Q-HDM experience nearly identical blueshifts in comparison to the classical resonances. The corresponding longitudinal resonances show noticeable spectrum shifts.
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| 13. |
- Kupresak, Mario, et al.
(author)
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Nonlocal Response of Plasmonic Nanostructures Excited by Dipole Emitters
- 2021
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In: Proceedings Elmar - International Symposium Electronics in Marine. - 1334-2630. ; 2021-September, s. 25-28
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Conference paper (peer-reviewed)abstract
- The interaction between light and plasmonic structures at the deep-nanometer scale, which is essentially governed by nonclassical effects, has been increasingly investigated by the hydrodynamic model. Several hydrodynamic models have been introduced, in order to describe the motion of the free electron gas in metals. In this work, by employing the hard wall hydrodynamic model (HW-HDM) and the quantum hydrodynamic model (Q-HDM), the nonlocal response of an isolated metallic nanoparticle, excited by a dipole emitter, is investigated. The analysis is performed for the local density of states of an emitter coupled with a spherical nanoparticle, which may be treated analytically. Both radial and tangential emitters are studied, while varying the emitter-nanoparticle separation, and the nanoparticle's size and material. It is shown that HW-HDM and Q-HDM may generate striking spectral features, which do not arise within the classical approach.
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| 14. |
- Marinovic, Tomislav, et al.
(author)
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Comparison of CBFM-Enhanced Iterative Methods for MoM-Based Finite Antenna Array Analysis
- 2022
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In: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 70:5, s. 3538-3548
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Journal article (peer-reviewed)abstract
- In this paper we compare different iterative techniques enhanced by the CBFM, that are used to analyze finite arrays of disjoint antenna elements. These are based on the stationary-type methods (Jacobi, Gauss-Seidel, macro-block Jacobi), the nonstationary GMRES and the hybrid alternating GMRES-Jacobi (AGJ) method which combines these two types. In each iteration, the reduced CBFM system is constructed based on the previous iterates, the solution of which is used to update the solution vector in the next iteration with improved accuracy. In this way, the convergence of the classical iterative techniques can be greatly improved. The convergence rates and computational costs of the CBFM-enhanced iterative methods are analyzed by considering several MoM-based problems. The GMRES-based method, which employs the block-Jacobi preconditioner, outperforms the other methods when the MoM matrix is ill-conditioned. For well-conditioned MoM matrices with reduced diagonal dominance due to increased presence of the inter-element coupling effects, the AGJ method or the methods based on the stationary-type iterations may require smaller computational effort to converge to the desired solution accuracy in comparison to the GMRES-based approach.
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| 15. |
- Marinovic, Tomislav, 1991, et al.
(author)
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Fast Characterization of Mutually Coupled Array Antennas Using Isolated Antenna Far-Field Data
- 2021
-
In: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 69:1, s. 206-218
-
Journal article (peer-reviewed)abstract
- A new method is proposed to analyze antenna arrays including mutual coupling, which is based on the concept of multiple scattering and relates to the iterative Jacobi and Gauss-Seidel methods. The method employs sampled far-field data of an isolated element, which can be obtained by any full-wave simulator and consists of far fields for excitation at the antenna feed and for plane waves with different angles of incidence. Mutual interactions between the array elements are modeled by approximating the incident field as a single dual-polarized plane wave taken from the spherical wave expansion of the scattered field from any other element in the array. The accuracy and run-time performances of the method are evaluated mainly by comparing simulations for several array geometries to MoM-based full-wave solutions. The method is primarily intended as a tool for the fast sequential analysis of arrays while varying the array lattice, particularly in case of irregular or sparse lattices and complex elements requiring dense meshes in full-wave simulators. The applications of the method may thus range from the systematic analysis of mutual coupling to optimization and synthesis.
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| 16. |
- Marinovic, Tomislav, 1991, et al.
(author)
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On the convergence of the iterative gauss-seidel-based electric field algorithm for the solution of antenna array mutual coupling
- 2021
-
In: 2020 International Symposium on Antennas and Propagation, ISAP 2020. ; , s. 271-272
-
Conference paper (peer-reviewed)abstract
- Recently, a new method for the solution of the antenna array mutual coupling (MC), which is based on the field data of an isolated element and relates to the iterative Gauss-Seidel method, has been proposed. In this paper, we study the convergence of the proposed method by comparing it with the convergence of the classical Gauss-Seidel iteration applied to a method-of-moments (MoM) system. Despite several approximations being used in the field-based method, similar behavior between the two methods has been observed, both in terms of the stability and the rate of the convergence.
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| 17. |
- Radiom, Soheil, et al.
(author)
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Antenna Miniaturization Influence on the Performance of Impulse Radio UWB system
- 2008
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In: Proceedings of the 1st European Wireless Technology Conference, EuWiT 2008. - NEW YORK : IEEE. - 9781424437931 ; , s. 362-365
-
Conference paper (other academic/artistic)abstract
- In this paper the effect of antenna miniaturization in a UWB system is presented. Modified small-size printed tapered monopole antennas are designed in different scaling sizes. In order to evaluate the antennas performance and their functionality, the performance of three kinds of UWB systems, Correlation Detection, Energy Detection and Transmitted Reference UWB, is studied in the presence of each antenna in the AWGN channel. The simulation results show that our designed antenna and its miniaturized geometries are suitable for UWB applications.
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| 18. |
- Radiom, Soheil, et al.
(author)
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Miniaturization of UWB Antennas and its Influence on Antenna-Transceiver Performance in Impulse-UWB Communication
- 2013
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In: Wireless personal communications. - : Springer Science and Business Media LLC. - 0929-6212 .- 1572-834X. ; 71:4, s. 2913-2935
-
Journal article (peer-reviewed)abstract
- In this paper, a co-design methodology and the effect of antenna miniaturization in an impulse UWB system/transceiver is presented. Modified small-size printed tapered monopole antennas (PTMA) are designed in different scaling sizes. In order to evaluate the performance and functionality of these antennas, the effect of each antenna is studied in a given impulse UWB system. The UWB system includes an impulse UWB transmitter and two kinds of UWB receivers are considered, one based on correlation detection and one on energy detection schemes. A tunable low-power Impulse UWB transmitter is designed and the benefit of co-designing it with the PTMA antenna is investigated for the 3.1-10.6 GHz band. A comparison is given between a 50 design and a co-designed version. Our antenna/transceiver co-design methodology shows improvement in both transmitter efficiency and whole system performance. The simulation results show that the PTMA antenna and its miniaturized geometries are suitable for UWB applications.
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| 19. |
- Schab, Kurt, et al.
(author)
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Energy Stored by Radiating Systems
- 2017
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Reports (other academic/artistic)abstract
- Though commonly used to calculate Q-factor and fractional bandwidth, the energy stored by radiating systems (antennas) is a subtle and challenging concept that has perplexed researchers for over half a century. Here, the obstacles in defining and calculating stored energy in general electromagnetic systems are presented from first principles as well as using demonstrative examples from electrostatics, circuits, and radiating systems. Along the way, the concept of unobservable energy is introduced to formalize such challenges. Existing methods of defining stored energy in radiating systems are then reviewed in a framework based on technical commonalities rather than chronological order. Equivalences between some methods under common assumptions are highlighted, along with the strengths, weaknesses, and unique applications of certain techniques. Numerical examples are provided to compare the relative margin between methods on several radiating structures.
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| 20. |
- Schab, Kurt, et al.
(author)
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Energy Stored by Radiating Systems
- 2018
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In: IEEE Access. - 2169-3536. ; 6, s. 10553-10568
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Journal article (peer-reviewed)abstract
- Though commonly used to calculate Q-factor and fractional bandwidth, the energy stored by radiating systems (antennas) is a subtle and challenging concept that has perplexed researchers for over half a century. Here, the obstacles in defining and calculating stored energy in general electromagnetic systems are presented from first principles as well as using demonstrative examples from electrostatics, circuits, and radiating systems. Along the way, the concept of unobservable energy is introduced to formalize such challenges. Existing methods of defining stored energy in radiating systems are then reviewed in a framework based on technical commonalities rather than chronological order. Equivalences between some methods under common assumptions are highlighted, along with the strengths, weaknesses, and unique applications of certain techniques. Numerical examples are provided to compare the relative margin between methods on several radiating structures.
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| 21. |
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