| 1. |
- Meyer, E., et al.
(author)
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The state of the art in beyond 5G distributed massive multiple-input multiple-output communication system solutions
- 2022
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In: Open Research Europe. - : F1000 Research Ltd. - 2732-5121. ; 2
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Research review (peer-reviewed)abstract
- Beyond fifth generation (5G) communication systems aim towards data rates in the tera bits per second range, with improved and flexible coverage options, introducing many new technological challenges in the fields of network architecture, signal pro- cessing, and radio frequency front-ends. One option is to move towards cell-free, or distributed massive Multiple-Input Multiple-Output (MIMO) network architectures and highly integrated front-end solutions. This paper presents an outlook on be- yond 5G distributed massive MIMO communication systems, the signal processing, characterisation and simulation challenges, and an overview of the state of the art in millimetre wave antennas and electronics.
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| 2. |
- Vilenskiy, Artem, 1988, et al.
(author)
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A Compact and Wideband MMIC to Ridge Gap Waveguide Contactless Transition for Phased Array Antenna Front-Ends
- 2024
-
In: IEEE Antennas and Wireless Propagation Letters. - 1548-5757 .- 1536-1225. ; 23:3, s. 990-994
-
Journal article (peer-reviewed)abstract
- A concept of a contactless in-line transition between a monolithic microwave integrated circuit (MMIC) and a ridge gap waveguide (RGW) is proposed and investigated at W-band. The transition employs an E-plane waveguide bifurcation obtained by mounting a GaAs MMIC on a supporting PCB in the opening of an RGW top metal lid. Designed this way, multiple contactless transitions can be placed in a row with an electrically small spacing that makes the transition idea suitable for array antenna front-ends. A transition equivalent circuit is constructed employing a single-mode transmission line model, which is verified through a full-wave simulation. An (85–105) GHz transition design is then developed and experimentally investigated in the back-to-back configuration indicating a (0.5–0.75) dB transition insertion loss. Finally, the performance of a 1-bit phase shifter MMIC, integrated into the RGW using two proposed transitions, is demonstrated.
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| 3. |
- Vilenskiy, Artem, 1988, et al.
(author)
-
Methods for Attenuating and Terminating Waves in Ridge Gap Waveguide at W_Band Carbon-Loaded Foam Carbonyl Iron Paint and Nickel Plating
- 2021
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In: 2021 51st European Microwave Conference, EuMC 2021. - 9782874870637
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Conference paper (peer-reviewed)abstract
- Several methods for electromagnetic waves matched termination and attenuation in a ridge gap waveguide (RGW) are experimentally investigated at W-band. At these frequencies, the implementation of matched loads and attenuators is especially complicated due to small sizes of RGW design features that limits application of traditional waveguide absorbing structures (e.g., absorbing sheets and finlines, ferrite insets, carbonyl iron walls, etc.). The following three techniques are considered: (i) filling an RGW gap with a carbon-loaded foam; (ii) covering a ridge (and pins) with a carbonyl iron paint; (iii) selective nickel plating of an RGW line segment. It was found that the first method exhibits a great broadband absorbing performance and can be easily implemented in a lab environment, whereas the second method can realize a more accurate and predictable attenuating performance. Finally, nickel plating allows for designing resonant RGW terminations and is more interesting from the industrial perspective.
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| 4. |
- Vilenskiy, Artem, 1988, et al.
(author)
-
Millimeter-Wave Quasi-Optical Feeds for Linear Array Antennas in Gap Waveguide Technology
- 2022
-
In: 2022 16th European Conference on Antennas and Propagation, EuCAP 2022.
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Conference paper (peer-reviewed)abstract
- A realization of the quasi-optical (QO) feed concept for linear millimeter-wave (sub-)array antennas is demonstrated in gap waveguide technology. The proposed feed architecture employs an input transition from a ridge gap waveguide (RGW) to a groove gap waveguide (GGW), a radial (H-plane sectoral) GGW section, and a transition to an output RGW array. A design decomposition approach is presented to reduce simulation complexity. Several 20-element QO feed implementations are investigated at W-band demonstrating a 20% relative bandwidth (85-105 GHz), 0.5 dB insertion loss, and a capability of an amplitude taper control within the 10-20 dB range.
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| 5. |
- Vilenskiy, Artem, 1988, et al.
(author)
-
Quasi-Optical Beamforming Network for Millimeter-Wave Electronically Scanned Array Antennas with 1-Bit Phase Resolution
- 2021
-
In: 15th European Conference on Antennas and Propagation, EuCAP 2021. ; , s. 1-5
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Conference paper (peer-reviewed)abstract
- State-of-the-art design solutions for electronically scanned array antennas are mostly limited to microwave to low mm-wave frequency bands, while the demand for new designs at higher frequencies (i.e. frequencies beyond 100 GHz) is rapidly growing. We attempt to fill in this knowledge gap by presenting a new linear array antenna architecture as a building block of 2D arrays that can enable efficient beam steering and a simplified array design. This concept is based on the combination of a low-loss quasi-optical (QO) feed, providing predefined antenna port excitation, with 1-bit phase shifters which are co-integrated with the array antenna elements. In this study, we formulate the array design problem as minimization of the sidelobe level (SLL) through an optimum quasi-randomization of phase errors. An analytical expression for the optimum focal ratio of the QO feed has been derived to establish the relationships between the key design parameters. These results are validated through numerical simulations revealing that the optimum focal ratio leads to the minimum SLL.
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| 6. |
- Vilenskiy, Artem, 1988, et al.
(author)
-
Wideband Reflection-Type p-i-n Diode Phase Shifters in GaAs MMIC Technology at W-Band
- 2023
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In: 2023 18th European Microwave Integrated Circuits Conference, EuMIC 2023. ; , s. 209-212
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Conference paper (peer-reviewed)abstract
- In this paper, we report on developing W-band GaAs p-i-n diode phase shifters (PSs) with a wideband phase and amplitude response. The PSs employ the reflection-Type architecture with reflective loads providing discrete phase tunability through diode dc control. We address the design challenge of having a stable phase shift and a minimal insertion loss imbalance for the diodes with a relatively low commutation quality factor at high millimeter-wave frequencies. Two PS examples, namely 180-and 90-degree bits, are designed for the targeted (85-105) GHz operating band. The circuits were fabricated in the commercial PIN-pHEMT GaAs process with 8 × 8 μm2,p-i-n diodes. Both simulated and measured results are in good agreement demonstrating wideband frequency performance.
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| 7. |
- Zhang, Yingqi, 1995, et al.
(author)
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A W-band Quasi-Optical Array Antenna Feeding Network with High Taper Efficiency Using Optimal Ridge Excitation of an H-Plane Sectoral Waveguide
- 2024
-
In: IEEE Antennas and Wireless Propagation Letters. - 1548-5757 .- 1536-1225.
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Journal article (peer-reviewed)abstract
- A novel H-plane quasi-optical (QO) feeding network for linear (sub-)array gap waveguide (GWG) antennas intended for beam-steering applications at W-band is presented. The QO feed comprises an H-plane sectoral GWG excited by an input stepped ridge gap waveguide (RGW) and transitioned to an overmoded rectangular groove gap waveguide (GGW) section, the latter being terminated with an array of RGW output probes. This work's key challenge and novelty is engineering the desired modal content in the QO structure for uniform amplitude excitation of array elements to enhance antenna gain with a low insertion loss. This was addressed by (i) realizing an optimal multi-mode excitation of the sectoral GWG and (ii) a proper phasing of a rich modal spectrum of the output overmoded GGW. An eigenmode-based semi-analytic approach was developed to investigate the impact of an input ridge length on the excited modal content and was shown to predict optimal results close to full-wave simulations. The demonstrated QO feed concept, applied to a 20-element array design, significantly outperforms existing solutions by achieving a 97% amplitude taper efficiency and showing less than 0.4 dB insertion loss over a 21% relative bandwidth (85–105 GHz).
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| 8. |
- Zhang, Yingqi, 1995, et al.
(author)
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Advanced Dielectric Resonator Antenna Technology for 5G and 6G Applications
- 2024
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In: Sensors. - 1424-8220. ; 24:5
-
Research review (peer-reviewed)abstract
- We review dielectric resonator antenna (DRA) designs. This review examines recent advancements across several categories, specifically focusing on their applicability in array configurations for millimeter-wave (mmW) bands, particularly in the context of 5G and beyond 5G applications. Notably, the off-chip DRA designs, including in-substrate and compact DRAs, have gained prominence in recent years. This surge in popularity can be attributed to the rapid development of cost-effective multilayer laminate manufacturing techniques, such as printed circuit boards (PCBs) and low-temperature co-fired ceramic (LTCC). Furthermore, there is a growing demand for DRAs with beam-steering, dual-band functions, and on-chip alignment availability, as they offer versatile alternatives to traditional lossy printed antennas. DRAs exhibit distinct advantages of lower conductive losses and greater flexibility in shapes and materials. We discuss and compare the performances of different DRA designs, considering their material usage, manufacturing feasibility, overall performance, and applications. By exploring the pros and cons of these diverse DRA designs, this review provides valuable insights for researchers in the field.
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| 9. |
- Zhang, Yingqi, 1995, et al.
(author)
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Broadband Dual-Polarized Differential-fed Filtering Antenna Array for 5G Millimeter-Wave Applications
- 2022
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In: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 70:3, s. 1989-1998
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Journal article (peer-reviewed)abstract
- This manuscript presents a novel broadband dual-polarized filtering patch antenna array using low-temperature co-fired ceramic (LTCC) process for 5G millimeter-wave applications. The filtering antenna element is implemented by using a ±45° polarized patch antenna fed by two pairs of differential L-type probes. An additional square ring and open strips are connected to each probe, resulting in radiation nulls and realizing the lower/upper stopband rejection level over 24 dB with skirt selectivity. The cross coupling among these structures not only introduces filtering responses, but also contributes to broadening the passband of 24.25-29.5 GHz covering 5G n257/n258/n261 bands. The antenna performance is validated by equivalent circuits based on transmission line models, which reveals clearly the principles of filtering antenna step by step and provides guidelines for further designs. The proposed filtering antenna element is expanded to a 4×4 filtering antenna array with shunt fed feeding networks. The spacing between elements is 0.48 λ0. The measured results demonstrate that the array performs good filtering characters including high stopband rejection, high selectivity, and wide upper stopband up to 40 GHz, where the antenna efficiency (considering radiations from all the directions) is less than 5%. In addition, the differential feeds provide symmetric radiation patterns with low cross-polarized counterparts. Compared with other reported works, the proposed filtering antenna/ array has excellent performances of wideband, high stopband rejection and wide upper stopband for potential 5G millimeter-wave applications.
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| 10. |
- Zhang, Yingqi, 1995, et al.
(author)
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Compact Wide-Scan Dual-Polarized Dielectric Resonator Antenna Array Based on LTCC Technology for Millimeter-Wave Applications
- 2023
-
In: 2023 International Conference on Electromagnetics in Advanced Applications, ICEAA 2023. ; , s. 96-99
-
Conference paper (peer-reviewed)abstract
- A compact dual-polarized (DP) dielectric resonator antenna (DRA) for two dimensional (2D) wide-angle scanning phased arrays operating at 28 GHz is presented. The proposed design is based on low-temperature co-fired ceramic (LTCC) technology by virtue of the benefits in terms of scalability at millimeter-wave (mmW) frequencies. The developed DRA element integrates two stacked cylindrical dielectric resonators (DRs) surrounded by a metal frame and is fed through a cross-shaped slot. An annular cavity separates the stacked DRs from the metal frame near the antenna aperture to enhance the active impedance-matching to air. The DRA element is analyzed in the infinite array environment and is characterized using an 8 × 8 array architecture consisting of 2 × 2 subarray tiles. This design is optimized for operation in the n261 band (27.5-28.35 GHz) with the active reflection coefficient ||Γ|| ≤ -10 dB across the targeted ±60° scan range. The array features a scan loss ranging from 3.2 dB to 3.9 dB in the H-, D-, and V-planes for both polarizations.
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