| 1. |
- Meyer, E., et al.
(författare)
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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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Ingår i: Open Research Europe. - : F1000 Research Ltd. - 2732-5121. ; 2
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Forskningsöversikt (refereegranskat)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.
(författare)
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Millimeter-Wave Quasi-Optical Feeds for Linear Array Antennas in Gap Waveguide Technology
- 2022
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Ingår i: 2022 16th European Conference on Antennas and Propagation, EuCAP 2022.
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Konferensbidrag (refereegranskat)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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| 3. |
- Zhang, Yingqi, 1995, et al.
(författare)
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Broadband Dual-Polarized Differential-fed Filtering Antenna Array for 5G Millimeter-Wave Applications
- 2022
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 70:3, s. 1989-1998
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Tidskriftsartikel (refereegranskat)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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| 4. |
- Zhang, Yingqi, 1995, et al.
(författare)
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Mutual Coupling Analysis of Open-Ended Ridge and Ridge Gap Waveguide Radiating Elements in an Infinite Array Environment
- 2022
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Ingår i: 2022 52nd European Microwave Conference, EuMC 2022. ; , s. 696-699
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Konferensbidrag (refereegranskat)abstract
- In this paper, we discuss mutual coupling effects in 2-D beam-steerable antenna arrays based on open-ended ridge and ridge gap waveguide radiating elements. Considering potential applications for beyond-5G systems in W-/D-band, the radiating elements are designed full-metal realizing a high radiation efficiency. Various decoupling structures based on electromagnetic soft surfaces are applied to suppress the surface waves over the array apertures. The infinite array approach is used to analyze antenna unit cells in an isosceles triangular lattice, which results in the active reflection coefficient over a scan and frequency range. The latter is used to extract the values of the mutual coupling coefficients between the elements. The analysis demonstrates the effect of decoupling structures realizing a steep drop of the mutual coupling magnitude (≤ − 20 dB) for closely-spaced array elements. This results in a wideband (≥ 20%) and wide-scan (> 50°) element beam-steering performance.
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| 5. |
- Zhang, Yingqi, 1995, et al.
(författare)
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Wideband Open-Ended Ridge Gap Waveguide Antenna Elements for 1-D and 2-D Wide-Angle Scanning Phased Arrays at 100 GHz
- 2022
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1548-5757 .- 1536-1225. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- A new antenna element type based on the open-ended ridge gap waveguide (RGW) is proposed for beam-steering phased array applications. This element type is of a particular interest at high mm-wave frequencies (≥ 100 GHz) owing to a contactless design alleviating active beam-steering electronics integration. The key challenge addressed here is a realization of a wide fractional bandwidth and scan range with high radiation efficiency. We demonstrate a relatively simple wideband impedance matching network comprised of an aperture stepped ridge segment and a single-pin RGW section. Furthermore, the E- and H-plane grooves are added that effectively suppress antenna elements mutual coupling. Results demonstrate a wide-angle beam steering (≥ 50°) over ≥ 20% fractional bandwidth at W-band with ≥ 89% radiation efficiency that significantly outperforms existing solutions at these frequencies. An experimental prototype of a 1×19 W-band array validates the proposed design concept through the embedded element pattern measurements.
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