| 1. |
- Chen, Jingjing, 1982, et al.
(författare)
-
Does LO Noise Floor Limit Performance in Multi-Gigabit Millimeter-Wave Communication?
- 2017
-
Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 27:8, s. 769-771
-
Tidskriftsartikel (refereegranskat)abstract
- Extremely high data rate communication can potentially be achieved by combining high-order modulations and wide bandwidths at millimeter-wave (mm-wave) frequencies. However, it has been challenging to practically implement this combination, even if the SNR of the system appears to be sufficiently high. An explanation from a recent theoretical study is that the practical data rates in mm-wave systems are limited by the local oscillator (LO) white phase noise. In this letter, we present an experimental investigation on whether the white noise floor of frequency multiplied LO sources is a major noise contribution to wideband signals. Hardware measurements are performed using multi-gigabit 64 quadrature amplitude modulation (QAM) signals. The measured results show that the transmitter performance degrades as the LO noise floor increases. Hence, the LO noise floor is identified to be one primary limitation for achieving the highest possible data rate in wideband mm-wave systems.
|
|
| 2. |
|
|
| 3. |
- Farjana, Sadia, 1983, et al.
(författare)
-
Realizing a 140 GHz Gap Waveguide–Based Array Antenna by Low-Cost Injection Molding and Micromachining
- 2021
-
Ingår i: Journal of Infrared, Millimeter and Terahertz Waves. - : Springer. - 1866-6892 .- 1866-6906. ; 42:8, s. 893-914
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a novel micromachining process to fabricate a 140 GHz planar antenna based on gap waveguide technology to be used in the next-generation backhauling links. The 140 GHz planar array antenna consists of three layers, all of which have been fabricated using polymer-based microfabrication and injection molding. The 140 GHz antenna has the potential to be used as an element in a bigger 3D array in a line-of-sight (LOS) multiple input multiple output (MIMO) configuration to boost the network capacity. In this work, we focus on the fabrication of a single antenna array element based on gap waveguide technology. Depending on the complexity of each antenna layer’s design, three different micromachining techniques, SU8 fabrication, polydimethylsiloxane (PDMS) molding, and injection molding of the polymer (OSTEMER), together with gold (Au) coating, have been utilized to fabricate a single 140 GHz planar array antenna. The input reflection coefficient was measured to be below − 11 dB over a 14% bandwidth from 132 to 152 GHz, and the antenna gain was measured to be 31 dBi at 140 GHz, both of which are in good agreement with the simulations. © 2021, The Author(s).
|
|
| 4. |
|
|
| 5. |
- Bagheri, Alireza, et al.
(författare)
-
A 16 × 16 45° Slant-Polarized Gapwaveguide Phased Array With 65-dBm EIRP at 28 GHz
- 2023
-
Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 71:2, s. 1319-1329
-
Tidskriftsartikel (refereegranskat)abstract
- A high equivalent isotropic radiated power (EIRP) active phased array antenna is proposed for fifth-generation (5G) communication systems at 28 GHz. The numerical design, measurements of a fabricated prototype, and performance analysis are presented. The antenna design is based on the gapwaveguide technology and consists of $16 \times 16$ single 45° slant-polarized elements. The proposed design uses a low complexity printed circuit board (PCB) structure with only six layers, i.e., a half of the existing wideband solutions. The array antenna incorporates up/downconverter integrated circuits (UDCs) and $1 \times 4$ transceiver beamformer integrated circuits (BFICs). Moreover, a compact and highly efficient transition at the end of each channel of the BFICs has been designed to interconnect the antenna elements with the PCB. The antenna's front-end loss, which includes the feed line, mismatch, and ohmic losses, is only 1.3 dB. The array covers the scanning range of ±60° in the azimuth plane and ±10° in the elevation plane. The $S_{11} < -10$ dB frequency bandwidth is from 26.5 to 29.5 GHz. The maximum EIRP of the antenna is 65.5 dBm at saturation point. The presented design offers a compact, robust, and low-loss performance solution meeting the high transmission power requirements of 5G applications.
|
|
| 6. |
- Bagheri, Alireza, et al.
(författare)
-
Micro strip to Ridge Gap Waveguide Transition for 28 GHz Steerable Slot Array Antennas
- 2020
-
Ingår i: 2020 14TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP 2020). - 2164-3342. - 9788831299008
-
Konferensbidrag (refereegranskat)abstract
- In this paper three types of contactless vertical transitions from microstrip to double ridge waveguide are presented. The designs are compact in size and robust, with improved isolation by employing a pin structure, making them ideal for SG mmWave phased arrays. All transitions cover the 26.5 - 29.5 GHz band, their dimensions are less than half a wavelength in pitch and have insertion losses less than 0.6 dB. The three designs apply different matching strategies and offer a trade-off between bandwidth and PCB areas. Finally, the behavior within an array configuration is analyzed.
|
|
| 7. |
- Bencivenni, Carlo, 1986, et al.
(författare)
-
Towards Integrated Active Antennas for 5G mm-wave Applications at Gapwaves
- 2018
-
Ingår i: 2018 IEEE Antennas and Propagation Society International Symposium and USNC/URSI National Radio Science Meeting, APSURSI 2018 - Proceedings. ; , s. 415-416
-
Konferensbidrag (refereegranskat)abstract
- Recently, in preparation for the upcoming 5G systems, the telecom industry has been showing a great interest in high frequency active antennas. We present a brief overview of the innovative design solution developed at Gapwaves for mmwave digital beamforming applications, capable of addressing all the associated technical issues. We review the general antenna architecture and components and explain how gapwaves technology enables us to achieve high performance, highly integrated active antennas in a cost effective way.
|
|
| 8. |
- Edstam, Jonas, et al.
(författare)
-
Backhaul evolution
- 2017
-
Ingår i: Ericsson Review (English Edition). - 0014-0171. ; 95:2, s. 24-36
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Microwave backhaul technology plays a significant role in providing reliable mobile network performance and is well prepared to support both the evolution of LTE and the introduction of 5G. Work has now started on the longer-term use of frequencies beyond 100GHz, targeting the support of 5G evolution toward 2030.
|
|
| 9. |
- Fang, Mu, 1992, et al.
(författare)
-
1-Dimensional Wide Scanning Gap Waveguide Based Slot Array Antenna using Decoupling Technique for 100 GHz Applications
- 2024
-
Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 72:4, s. 3438-3450
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a 1-dimenional wide scanning slot array antenna based on ridge gap waveguide (RGW), operating at a 100 GHz band. A novel half wall decoupling structure is proposed to reduce the mutual coupling and the reflection coefficient simultaneously, thus achieving a more stable active reflection coefficient (ARC) within the ±60° scanning range. At the same time, special attention has been given in retaining the embedded pattern suitable for wide scanning performance. An 8-element slot array antenna (8×8 slots) with two different feeding networks is fabricated and measured to verify the scanning performance. The prototype achieves 91% total efficiency while scanned up to 60° with 3 dB scanning loss. The measured results show good agreement with the simulations both for the reflection coefficient and radiation performance.
|
|
| 10. |
- Herlitz, Johan, 1949, et al.
(författare)
-
Determinants of time to discharge following coronary artery by pass grafting.
- 1997
-
Ingår i: European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery. - 1010-7940. ; 11:3, s. 533-8
-
Tidskriftsartikel (refereegranskat)abstract
- To describe clinical factors prior to and at the time of coronary artery bypass grafting (CABG) associated with the number of days until hospital discharge.
|
|
