| 1. |
- Pivnenko, Sergiy, et al.
(författare)
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Using a Conical Horn as Compact Antenna Test Range Feed in Millimetre Bands
- 2022
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Ingår i: 2022 16th European Conference on Antennas and Propagation, EuCAP 2022.
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Konferensbidrag (refereegranskat)abstract
- Using a conical horn as a feed for a single offset-fed Compact Antenna Test Range (CATR) is described. Although such horn has larger variation of the phase centre with frequency and slightly different beamwidth in the E-plane and H-plane within the used field of view, as compared to a specially designed corrugated horn feed, good results were obtained for the measured amplitude and phase variations in the Quiet Zone at mm-band. Some details of application of conventional conical horns as CATR feeds are also explained.
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| 2. |
- Uz Zaman, Ashraf, 1975, et al.
(författare)
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3D Printed Periodic Structures for RF Packaging of Integrated Array Module at sub-6GHz Band
- 2021
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Ingår i: 2021 International Symposium on Antennas and Propagation, ISAP 2021.
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Konferensbidrag (refereegranskat)abstract
- Wideband PMC packaging solution fabricated by low cost 3D printing technology has been proposed as an alternative to conventional metal wall solution for isolating critical active circuits in integrated arrays operating at sub-6GHz. The two proposed periodic structures named as triangular pins and conical pins produce a parallel-plate stopband over the frequency range from 2.5-6GHz and 2.1-5.5GHz respectively. A test structure, containing passive microstrip lines placed on a FR4 substrate, has been used to verify the packaging performance of the proposed 3D printed structures and the measured isolation performance of the newly proposed periodic structures agree very well with the simulated performance. Isolation level better than 40-50dB has been demonstrated within the band of interest.
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| 3. |
- 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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| 4. |
- Albadalejo Lijarcio, Juan Luis, 1994, et al.
(författare)
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Substrate-Less Vertical Chip-to-Waveguide Transition for W-Band Array Antenna Integration
- 2023
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Ingår i: 2023 17TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION, EUCAP. - 2164-3342. - 9788831299077
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Konferensbidrag (refereegranskat)abstract
- This paper presents a vertical transition from a high permittivity GaAs MMIC to rectangular waveguide using bondwires as a coupling structure. The transition is advantageous for the direct integration of any off-the-shelf chip into a waveguide antenna since no modification of the GSG-pad or additional substrate is needed. An EBG structure consisting of pins is used for the packaging of the chip in order to avoid field propagation in undesired directions. The simulations results show that the reflection coefficient is lower than -10 dB and the average insertion loss is better than 0.5 dB from around 87 to 101 GHz (14% relative bandwidth).
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| 5. |
- Alibakhshikenari, Mohammad, et al.
(författare)
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Dual-Polarized Highly Folded Bowtie Antenna with Slotted Self-Grounded Structure for Sub-6 GHz 5G Applications
- 2022
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 70:4, s. 3028-3033
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a novel dual-polarized highly-folded self-grounded Bowtie antenna that is excited through I-shaped slots is proposed for applications in sub-6GHz 5G multiple-input-multiple-output (MIMO) antenna systems. The antenna consists of two pairs of folded radiation petals whose base is embedded in a double layer of FR-4 substrate with a common ground-plane which is sandwiched between the two substrate layers. The ground-plane is defected with two I-shaped slots located under the radiation elements. Each pair of radiation elements are excited through a microstrip line on the top layer with RF signal that is 180° out of phase with respect to each other. The RF signal is coupled to the pair of feedlines on the top layer through the I-shaped slots from the two microstrip feedlines on the underside of the second substrate. The proposed feed mechanism gets rid of the otherwise bulky balun. The Bowtie antenna is a compact solution with dimensions of 32 32 33.8 mm3. Measured results have verified that the antenna operates over a frequency range of 3.1–5 GHz and exhibits an average gain and antenna efficiency in the vertical and horizontal polarizations of 7.5 dBi and 82.6%, respectively.
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| 6. |
- Auriacombe, Olivier, 1989, et al.
(författare)
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Oil, water, and ice detection on road surfaces with a millimeter-wave radiometer
- 2020
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 11533
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Konferensbidrag (refereegranskat)abstract
- Passive radiometers are well-known instruments used in the characterization of soil, sea surfaces and remote sensing of the earth atmosphere with satellites or airplanes. The instrument described in this article is a dual-polarised superheterodyne radiometer operating around 93 GHz. It is placed on a structure to measure road surface conditions (ice, water or oil) in a laboratory-controlled environment. This radiometer measures the reflected and emitted radiations from the road surface (asphalt and concrete) and the background temperature, in two orthogonal polarizations (H and V). The difference in the dielectric properties of the ice, oil and water from dry road surface allows to distinguish them efficiently. This kind of technique can be used for road surface recognition in all weather conditions and does not require presence of daylight or other sources of illumination. In this paper, calibration procedures and radiometric characterisations of the radiometer are studied in order to select the best and simpler method to operate the radiometer. It was found that calibrating the radiometer with only one blackbody target or using a table of gain and system noise temperature is sufficiently accurate over a long time to be able to distinguish dry from ice or water covered surfaces. The laboratory results are showing a high difference in the brightness temperature between road surface covered with ice, water or oil and the dry road surface. No ambiguities between those conditions exist but potential limitations could rise, for example if the road surface roughness changes during a measurement. Those promising results validate the potential of using radiometer for road safety and the automotive industry. The presented laboratory measurements are the first step towards the implementation of the instrument into a moving vehicle for alerting drivers ahead of unforeseen dangers. Downloading of the abstract is permitted for personal use only.
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| 7. |
- Auriacombe, Olivier, 1989, et al.
(författare)
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Road Surface Characterization Using a Radiometer at 100 GHz
- 2020
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Ingår i: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035. ; 2020-November, s. 136-137
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Konferensbidrag (refereegranskat)abstract
- A dual polarization super-heterodyne radiometer operating between 85 and 100 GHz has been developed and used for surface characterization. The instrument can detect changes from dry to icy road in many environmental conditions (night, fog, rain) by measuring the combination of reflected/transmitted radiation from the surface at two orthogonal polarizations. The difference in brightness temperature between those polarizations is an accurate tool to distinguish ice from dry road surfaces. Results from measurement of dry asphalt and ice layers on asphalt are presented in this paper.
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| 8. |
- Chen, Lei, et al.
(författare)
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A Method of Reducing Mutual Coupling for a Finite Array
- 2020
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Ingår i: 14th European Conference on Antennas and Propagation, EuCAP 2020. - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- A method of reducing mutual coupling for a finite array with the characteristics of wideband and beam steering is presented in this paper. By adding an extra decoupling network, the mutual coupling can be efficiently suppressed for the antenna array. To verify the validity of the proposed method, a 1 x 8 millimeter-wave array antenna based on the gap waveguide technology is used in this work. The simulation results show that the active reflection coefficients are improved from 6.98 dB to -8.29dB, and the mutual coupling between adjacent elements is reduced to below -16.73 dB covering 20-33 GHz with the beam steering angle range of +/- 70 degrees.
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| 9. |
- Fang, Mu, 1992, et al.
(författare)
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1-Dimensional Wide Scanning Gap Waveguide Based Slot Array Antenna using Decoupling Technique for 100 GHz Applications
- 2024
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 72:4, s. 3438-3450
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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.
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| 10. |
- Fang, Mu, 1992, et al.
(författare)
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A Comparative Study of Decoupling Techniques for Waveguide Slot Array Antennas
- 2024
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Ingår i: 18th European Conference on Antennas and Propagation, EuCAP 2024.
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present a comparative study of three decoupling techniques for waveguide slot array antennas, including half wall, corrugation and metal fence. Their decoupling efficacy and impact on element patterns are investigated under two typical element spacings: 0.5λ0 and 1λ0. A summary highlighting the differences among these three decoupling techniques is provided to gain insight into which specific application scenarios are best suited for each technique.
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