69 research outputs found

    A low-profile wideband compressed single-arm spiral antenna array for mid-band 5G beam steering applications

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    A low profile wideband spiral antenna array is presented for global mid-band 5G beam steering applications. In the global rollout of mid-band 5G, different frequencies have been licensed within each region (e.g. 3.4–3.8 GHz in the EU and 3.7–5 GHz in the USA). Therefore, antenna arrays must be able to cover a bandwidth of 3.3 GHz to 5 GHz to provide true global coverage. Initially, this work presents the design of a wideband compressed spiral antenna that provides an axial beam throughout its operational bandwidth of 3.3 GHz to 5 GHz, enabling beam steering functionality. Then, this antenna has been placed in a 4 × 4 array with a triangular lattice. The proposed spiral antenna array can provide a scanning range of − 40° ≤ θ ≤  + 40° in all azimuth directions with an average back lobe level of less than − 9.5 dB. This development will allow for low-cost integration of 5G systems for global use, such as passenger aircraft, UAVs, drones, and marine and ground vehicles

    A Circularly Polarized Low-Cost Flat Panel Antenna Array With a High Impedance Surface Meta-Substrate for Satellite On-the-Move Medical IoT Applications

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    A 1×3 linear antenna array consisting of Quad-Arm Curl antenna with a High impedance meta-surface (QACH) is presented. We believe that it is the first linear phased array solution which can provide 360° azimuth coverage. This array has been designed to operate at L-Band (1.518 - 1.675 GHz) and generate right hand circularly polarized radiation to primarily target the Inmarsat BGAN satellite constellation. The metamaterial structure integrated into each antenna element allows a low-profile height of 17.2 mm (λ1.597/10.9). Since the curl element has wideband characteristics, the array is able to provide shared aperture functionality. The array guarantees high gain beam steering for low elevation angles (up to θ = 70° from the zenith) with an average gain of 7.96 dBic at θ = 70°. In comparison, to achieve an equivalent high gain a conventional 4×5 patch array would be required (3 elements vs 20 elements). This means that the proposed array requires 80% fewer phase shifters, amplifiers and LNAs. This translates to a crucial commercial advantage in relation to manufacturing cost. This development can lead to disruption of the existing Satcom market by lowering the barrier-to-entry for customers looking for a mass deployable, low-cost IoT on Satcom solution

    Elevating expression of MeCP2 T158M rescues DNA binding and Rett syndrome–like phenotypes

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    Mutations in the X-linked gene encoding methyl-CpG–binding protein 2 (MeCP2) cause Rett syndrome (RTT), a neurological disorder affecting cognitive development, respiration, and motor function. Genetic restoration of MeCP2 expression reverses RTT-like phenotypes in mice, highlighting the need to search for therapeutic approaches. Here, we have developed knockin mice recapitulating the most common RTT-associated missense mutation, MeCP2 T158M. We found that the T158M mutation impaired MECP2 binding to methylated DNA and destabilized MeCP2 protein in an age-dependent manner, leading to the development of RTT-like phenotypes in these mice. Genetic elevation of MeCP2 T158M expression ameliorated multiple RTT-like features, including motor dysfunction and breathing irregularities, in both male and female mice. These improvements were accompanied by increased binding of MeCP2 T158M to DNA. Further, we found that the ubiquitin/proteasome pathway was responsible for MeCP2 T158M degradation and that proteasome inhibition increased MeCP2 T158M levels. Together, these findings demonstrate that increasing MeCP2 T158M protein expression is sufficient to mitigate RTT-like phenotypes and support the targeting of MeCP2 T158M expression or stability as an alternative therapeutic approach

    Reconfigurable Phased Array Antenna Consisting of High-gain High-Tilt Circularly Polarized Four-arm Curl elements for Near Horizon Scanning Satellite Applications

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    A 2×2 phased array consisting of beam reconfigurable four-arm Right Handed Circularly Polarized (RHCP) curl unit element antennas is presented. This array is designed at test frequency of 5.2 GHz and can undertake a high-gain near-the-horizon scanning with low grating lobes. Each curl antenna element has four ports and can provide four RHCP tilted-beams ( θ = 48°) with a gain of 8.3 dBic. By switching the feeding ports, the curl element can reconfigure / switch these unit element beams in four different quadrants in space. The array exploits these high-gain high-tilt switchable beams for generating an extremely wide scanning range from -80° ≤θ≤ +80°. For the 2×2 array, in this range, the beam has a maximum gain of 12.4 dBic at θ = 40°. More importantly, the array provides RHCP beams with a gain of 10.5 dBic at near-the-horizon angles of θ≈ 70° and provides a lower gain of 6.5 dBic in the zenith direction. This has promising applications in Communications On The Move (COTM) using Flat Panel Antenna (FPA) to Geosynchronous Orbit (GSO) satellites. Here, when operating at high latitudes require high-gain at near-the-horizon angles

    Radar Cross Section Analysis of Two Wind Turbines via a Novel Millimeter- Wave Technique and Scale Model Measurements

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    A novel, low cost, highly accurate, millimeter-wave RCS characterization method is developed and presented in this paper. In order to develop and verify the validity of the proposed method, full scale models and scale models of the horizontal-axis wind turbine (HAWT) and Crossflow turbines have been simulated and compared for a case study. The RCS of a scaled Crossflow turbine model was then experimentally verified using the novel method presented at frequencies of 76-81GHz. The proposed method utilizes the AWR1843BOOST evaluation board and DCA1000EVM real-time high-speed data capture card from Texas Instruments. To the best of the authors’ knowledge, this is the first RCS analysis of a scaled model performed at the mm-wave frequencies of 76-81GHz. This novel method is quick, simple, and fully automated, while maintaining high accuracy. Additionally, this has been achieved at a low cost using commercially available off the shelf parts. Good agreement was observed between the simulated and experimental results. Comparing the RCS data of the two turbines, it appears that the Crossflow turbine geometry offers a lower RCS and Doppler spectrum contamination as compared with a traditional horizontal axis wind turbine structure. These results are necessary and useful in allaying the increasing concerns regarding wind turbine radar interference, which have appeared as a result of the widespread adoption of wind power generation in recent years

    A low-profile wideband compressed single-arm spiral antenna array for mid-band 5G beam steering applications.

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    A low profile wideband spiral antenna array is presented for global mid-band 5G beam steering applications. In the global rollout of mid-band 5G, different frequencies have been licensed within each region (e.g. 3.4-3.8 GHz in the EU and 3.7-5 GHz in the USA). Therefore, antenna arrays must be able to cover a bandwidth of 3.3 GHz to 5 GHz to provide true global coverage. Initially, this work presents the design of a wideband compressed spiral antenna that provides an axial beam throughout its operational bandwidth of 3.3 GHz to 5 GHz, enabling beam steering functionality. Then, this antenna has been placed in a 4 × 4 array with a triangular lattice. The proposed spiral antenna array can provide a scanning range of - 40° ≤ θ ≤  + 40° in all azimuth directions with an average back lobe level of less than - 9.5 dB. This development will allow for low-cost integration of 5G systems for global use, such as passenger aircraft, UAVs, drones, and marine and ground vehicles

    Low Cost Millimetre-Wave Scale Model RCS Characterisation

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