| 1. |
- Albadalejo Lijarcio, Juan Luis, 1994, et al.
(författare)
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Low-cost Coaxial Slot Array Antenna for E-band Automotive Corner Radar Applications Based on Gap Waveguide MLW Technology
- 2024
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Ingår i: 18th European Conference on Antennas and Propagation, EuCAP 2024.
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Konferensbidrag (refereegranskat)abstract
- This paper presents an E-band automotive radar antenna based on multilayer waveguide (MLW) technology. The electromagnetic fields propagate through a low-loss air-filled coaxial transmission line created by the stacking of three separate metal sheets. The fundamental antenna element consists of a single side-fed column composed of six in-line slots. An electromagnetic bandgap (EBG) structure is integrated along the transmission lines to mitigate the unwanted leakage resulting from small air gaps between the metal sheets. The fabrication of the prototype was realized by using a quick and cost-effective sheet metal manufacturing process, which has proven to be highly suitable for large-scale production. The measurement results for both radiation pattern and reflection coefficient agree with the corresponding simulations within the operating frequency band ranging from 76 to 81 GHz. The measurements results demonstrate a return loss better than 10 dB across the designated frequency band and the realized gain of the antenna is, on average, 11.5 dBi, with a beam width of 120 degrees in azimuth (E-plane) and 20 degrees in elevation (H-Plane).
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| 2. |
- Amani, Navid, 1985, et al.
(författare)
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MIMO Channel Capacity Gains in mm-Wave LOS Systems with Irregular Sparse Array Antennas
- 2017
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Ingår i: APWC 2017.
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Konferensbidrag (refereegranskat)abstract
- This paper investigates potential advantages of linear irregular sparse antenna arrays over their regular counterparts in a mm-wave line-of-sight (LOS) multiple-input multiple-output (MIMO) scenario. The comparison is based on numerical computations of MIMO eigenvalues of the corresponding channel matrices and the resulting channel capacity. Identical linear antenna arrays are assumed at the transmitter and the receiver sides. The compared regular and irregular arrays have an equal aperture length. Mutual coupling between elements within an array is assumed negligible due to the array sparsity. A 4×4 MIMO channel is studied, where we change the position of the two inner elements to obtain irregularly spaced arrays. It is shown that for some specific distances between TX and RX, the irregular array distribution can significantly improve the channel capacity in LOS. This observation opts for reconfigurable array designs.
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| 3. |
- Ayebe, Mustafa, 1997, et al.
(författare)
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Systematic Self-Interference Mitigation in Full Duplex Antenna Arrays Via Transmit Beamforming
- 2023
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Ingår i: 2023 International Conference on Electromagnetics in Advanced Applications, ICEAA 2023. ; , s. 158-163
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Konferensbidrag (refereegranskat)abstract
- The optimal antenna array excitation vector is derived that maximizes the (realized) array gain in a particular direction while preventing the coupled input power to the low-noise amplifiers on the receive side to exceed a certain maximum threshold level. This is very useful for in-band full-duplex systems where the hardware complexity for self-interference cancellation must be minimized. In this approach, the perfect nulling of interference on the RX side is not required, sparing degrees of freedom for the TX beamformer. We evaluate the performance of the proposed TX beamforming algorithm by showing numerical results of the 25 x-polarized TX and 25 RX with 0.5λ element spacing and λ gap distance between the TX and RX sub-array.
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| 4. |
- Bagheri, Alireza, et al.
(författare)
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A 16 × 16 45° Slant-Polarized Gapwaveguide Phased Array With 65-dBm EIRP at 28 GHz
- 2023
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 71:2, s. 1319-1329
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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.
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| 5. |
- Bagheri, Alireza, et al.
(författare)
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Micro strip to Ridge Gap Waveguide Transition for 28 GHz Steerable Slot Array Antennas
- 2020
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Ingår i: 2020 14TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP 2020). - 2164-3342. - 9788831299008
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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.
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| 6. |
- Bagheri, Alireza, et al.
(författare)
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MmWave array antenna based on gap waveguide technology for 5G applications
- 2019
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Ingår i: Proceedings of the 2019 21st International Conference on Electromagnetics in Advanced Applications, ICEAA 2019. ; , s. 492-494
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Konferensbidrag (refereegranskat)abstract
- The gap waveguide technology has been shown to provide low loss and easy-to-manufacture antenna solutions in the mmWave frequencies. A gap waveguide array antenna with scanning ability within ±45° designed with focus on 5G applications is presented here. The computed active reflection coefficient of the array is less than -10 dB for all scan angles and the broadside gain is 23 dBi. The proposed antenna can be integrated with active components to increase EIRP and coverage range.
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| 7. |
- Bagheri, Alireza, et al.
(författare)
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TX Beamforming EVM Performance of a 65 dBm-EIRP Slant-Polarized Gapwaveguide Phased Array at 28 GHz
- 2023
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Ingår i: 17th European Conference on Antennas and Propagation, EuCAP 2023.
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Konferensbidrag (refereegranskat)abstract
- The transmit error vector magnitude (EVM) performance measurements of a slant-polarized 28 GHz gapwaveguide-based phased array is analyzed in this paper. The performance is studied by using a large range of signals, with varied powers, symbol rates, and quadrature amplitude modulation (QAM) orders. The measurements have been conducted for four different scanning angles. A non-standardized over-the-air (OTA) link between the phased array and the receiver in a laboratory environment is used. The results show that the phased array antenna supports a 31 dB effective isotropic radiated power (EIRP) dynamic range at a maximum 2% EVM when transmitting a 64QAM modulated signal with 250 MS/s symbol rate at all scanning directions.
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| 8. |
- Bencivenni, Carlo, et al.
(författare)
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5G mmWave Beam Steering Antenna Development and Testing
- 2019
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Ingår i: 13th European Conference on Antennas and Propagation, EuCAP 2019. - 9788890701887
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Konferensbidrag (refereegranskat)abstract
- mmWave frequencies offer unprecedented capacity but also new technical challenges. Current solutions typically adopt integrated PCB antennas, however they still face issues when it comes to coverage, power consumption and cost. Instead, we present a SG mmWave antenna platform demonstrating a different approach based on Gapwaves technology. The proposed design is an integrated all-metal multi-layer assembly, offering low-loss feeding, high-gain subarray, high-Q filters and exceptional thermal handling. To support these claims, active measurement of beam steering, EIRP and temperature are presented. Results from this small demonstration unit are very encouraging and show performance challenging that of much larger systems.
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| 9. |
- Bencivenni, Carlo, 1986, et al.
(författare)
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A Simple Method for Optimal Antenna Array Thinning Using a Broadside MaxGain Beamformer
- 2013
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Ingår i: 7th European Conference on Antennas and Propagation, EuCAP 2013, Gothenburg, Sweden, 8-12 April 2013. - 2164-3342. - 9788890701832 ; , s. 1799-1802
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Konferensbidrag (refereegranskat)abstract
- A simple and effective method for optimal antenna array thinning employing a broadside-scanned maximum gain beamformer is presented. Starting from a fully populated λ/2-spaced regular lattice, the array is thinned by progressively 'turning off' the element(s) with the lowest weight(s) of the weight vector realizing maximum gain. The accuracy and effectiveness of the method is validated against a rigorous combinatorial search method that can be used to find the optimal irregular array configuration solution in small to moderate-sized arrays. Furthermore, to evaluate the robustness of the proposed approach, the effects of beam steering have been investigated for linear arrays consisting of 10-40 antenna elements as well. Good results can be obtained for close to broadside scanned arrays, which is of importance for the directly radiating arrays that are currently being considered as modern satellite systems.
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| 10. |
- Bencivenni, Carlo, 1986, et al.
(författare)
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Aperiodic Array Antennas for Future Satellite Systems
- 2014
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Ingår i: Swedish Microwave Days March 11-12, 2014, Gothenburg, Sweden.
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Konferensbidrag (refereegranskat)abstract
- Today, most satellite systems employ reflector antennas to generate narrow beams covering a certain area of Earth’s surface from orbit. However, the performance specification of modern communication systems require an increasing demand on the multi-beam, multi-channel, dual-polarization and beam shaping capabilities, which renders the design of such complex systems to a major challenge.A worldwide view is that Direct Radiating Arrays (DRAs) will be part of the future satellite systems. DRAs can handle these complexities, but the design solutions, based on conventional regular arrays are expensive due to a large number of required array elements (100-1000 in dense array for geosynchronous orbit) and active components, such as low noise and power amplifiers. For this reason, aperiodic or sparse arrays, where the array layout is optimized, constitute a very attractive solution for minimizing the number of elements and thus the cost.To design aperiodic arrays, Array Signal Processing (ASP) based methods are commonly used, which are advantageous when optimizing for complex antenna beam specifications [1-2], but often assume idealized antenna elements (e.g. isotropic radiators or uniform field apertures) while ignoring antenna mutual coupling and edge truncation effects. Electro-Magnetic Simulations (EMS) overcome these drawbacks [3], but their use is limited to simplistic ASP schemes. Due to extreme computational demands, such methods are primarily used to evaluate beam performance degradation effects, but do not incorporate sparse array ASP design procedures, and hence, these approaches result in suboptimal solutions. Our aim is to enhance the current methodology by accounting for realistic elements and critical array effects in a rigorous numerical manner, while adapting advanced ASP algorithms for fulfilling the required specifications
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