1,720,956 research outputs found
L/S-Band Frequency Reconfigurable Multiscale Phased Array Antenna With Wide Angle Scanning
No full textA frequency reconfigurable phased array element is presented. The operational band of the single port L/S-band antenna can be selected by modifying the element apertures with p-I-n diode switches. The antenna element satisfies strict requirements on its frequency band separation (2.2:1), size, feeding structure and control lines to be integrated into a phased array system. A multi-scale array topology is proposed to achieve wide angle scanning (±60°) in both operational bands of the array.Accepted author manuscriptMicrowave Sensing, Signals & System
Dual-band wide-angle scanning planar phased array in X/Ku-bands
No full textAccepted author manuscriptMicrowave Sensing, Signals & System
Synthesis of Optimal 5G Array Layouts With Wide-Angle Scanning and Zooming Ability for Efficient Link Setup and High-QoS Communication
No full textAn irregular antenna synthesis technique with jointly optimized array subset layouts has been proposed for efficient beam setup and reliable communication in 5G. The proposed approach addresses both the electromagnetic and thermal challenges in 5G arrays by integrating zooming and wide-angle scanning functionality into interleaved-shared layout aperiodic arrays with low side lobes. The effectiveness of the proposed method is demonstrated via simulations by using a 64-element array and its smartly thinned subsets.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microwave Sensing, Signals & System
Semi-active multiple beam arrays
No full textThe low power efficiency (5-15%) of solid state power amplifiers, working in back-off to guarantee a good linearity, could become the show stopper for some future space and terrestrial communication ventures at Ka-band and above. Semi-active reflector and conformal antennas, using Butler-like matrices between the power amplifiers and the feed elements, were first introduced to directly generate flexible multiple beams most efficiently.For linear and planar arrays, such phase-only control at power amplifier inputs can provide beam zooming or amplitude tapering, but no proper beam steering. The paper discusses and analyses the extension of the semi-active principle to linear and planar arrays, by use of multiport amplifiers with amplitude and phase input control to power the elements most efficiently.Performances and limitations of such systems are analyzed and demonstrated for a few examples.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microwave Sensing, Signals & System
System Advantages of Using Large-Scale Aperiodic Array Topologies in Future mm-Wave 5G/6G Base Stations: An Interdisciplinary Look
No full textThe encouraging potential of employing large-scale aperiodic base station arrays in addressing the radiation pattern and thermal requirements of the next generation communication systems is demonstrated. Sample 256-element layout-optimized multibeam arrays are presented as a futuristic view. The system benefits (in terms of the statistical Quality-of-Service, energy efficiency, thermal management and processing burden) of the proposed arrays, as well as their performance versus design complexity trade-offs, are explained through interdisciplinary simulations. The key advantage of the proposed antennas overthe currently proposed 64-element periodic arrays is identified as the increased gain with much lower side lobes, which yields much less power and less heat per element with more surface for cooling, and allows robust/computationally-efficient precoding.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microwave Sensing, Signals & System
Planar dual-band wide-scan phased array in X-band
No full textThe design of a planar dual-band wide-scan phased array is presented. The array uses novel dual-band comb-slot-loaded patch elements supporting two separate bands with a frequency ratio of 1.4:1. The antenna maintains consistent radiation patterns and incorporates a feeding configuration providing good bandwidths in both bands. The design has been experimentally validated with an X-band planar 9 × 9 array. The array supports wide-angle scanning up to a maximum of 60 ° and 50 ° at the low and high frequency bands respectively.Accepted author manuscriptMicrowave Sensing, Signals & System
Two-Port Dual-Band Microstrip Square-Ring Antenna for Radar Applications
No full textA novel two-port, dual-band square-ring microstrip antenna element for wide-angle scanning planar phased array is proposed. The two ports are used to operate the antenna array over the L and S radar bands. Microstrip square-ring radiators are chosen due to their smaller dimensions compared to the conventional microstrip patch. To extend operational bandwidth, the square rings placed into a single layer are fed by small coupling patches. The antenna elements demonstrate consistent radiation patterns and sufficient bandwidths in both operational bands. Due to its dimensions, the element is well-suited for application to wide-scan phased arrays.Accepted Author ManuscriptMicrowave Sensing, Signals & System
Shaped Elevation Patterns for 5G Base Stations
No full textThis paper discusses the advantages and an example of using shaped elevation patterns for 5G base stations. A simple iterative power synthesis method involving the phase of shaped patterns, and suitable for both center- and end-fed sub-arrays, is used. Numerical simulations and some experimental results for an array of linear sub-arrays with cosecant squared patterns are presented to validate the concept.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microwave Sensing, Signals & System
System Impacts of User Scheduling with Minimal Angular Separation Constraints in Radio Resource Management for 5G and Beyond
No full textThe system effects and trade-offs of varying the minimal angular separation among multiple simultaneous co-frequency users are investigated for a high-capacity multibeam communication scenario. Through the statistical system simulations, it is demonstrated that the optimal (non-zero) value of the required separation depends on the base station array size, number of users, precoding technique, desired probability of coverage and intended quality of service.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microwave Sensing, Signals & System
Phase-Only Control of Peak Sidelobe Level and Pattern Nulls Using Iterative Phase Perturbations
No full textMinimization of the maximum sidelobe level for a given array geometry, amplitude distribution, and nulling sectors by phase-only adjustment of the element coefficients is studied. Nonlinear optimization problem for phase distribution is solved using a novel iterative convex optimization algorithm, which includes mutual coupling effects and exploits small phase perturbations at each step. Superiority of the algorithm in terms of the peak sidelobe level and nulling depth achieved over several optimization methods reported in the most relevant literature is demonstrated in several case studies. Finally, a case study is performed to demonstrate added value of the algorithm for millimeter-wave fifth generation application with phase-only radiation pattern forming.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microwave Sensing, Signals & System
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