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Phased array

About: Phased array is a research topic. Over the lifetime, 19428 publications have been published within this topic receiving 229231 citations. The topic is also known as: Phased Array Radar, PAR.


Papers
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PatentDOI
TL;DR: In this article, a transducer is coupled with drive circuitry for providing drive signals to the transducers at one of a plurality of discrete RF frequencies, while controlling a phase component of the drive signals.
Abstract: Systems and methods for performing a therapeutic procedure using focused ultrasound include providing a piezoelectric transducer including a plurality of transducer elements (22), such as a concave concentric ring array or a linear array of transducer elements. Drive circuitry (14) is coupled to the transducer for providing drive signals to the transducer elements at one of a plurality of discrete RF frequencies. A controller (16) is coupled to the drive circuitry for periodically changing a frequency of the drive signals to one of the plurality of discrete frequencies, while controlling a phase component of the drive signals to maintain the focus of the transducer at a primary focal zone during a single sonication.

243 citations

Journal ArticleDOI
TL;DR: An annular phased array electromagnetic (EM) radiating device has been developed to surround regions of the body with penetrating EM fields and methods for steering the deep heating patterns have been demonstrated and evaluated.
Abstract: An annular phased array electromagnetic (EM) radiating device has been developed to surround regions of the body with penetrating EM fields. This instrument uses synchronous fields to focus energy at the center of a body placed in the aperture. Methods for steering the deep heating patterns have also been demonstrated and evaluated, as well as a minimally perturbing electric field (E-field) sensor to monitor the strength of the EM fields outside the body.

243 citations

Patent
Carsten Metz1
08 Mar 2004
TL;DR: In this article, an efficient, low-loss, low sidelobe, high dynamic range phased-array radar antenna system was proposed that uses metamaterials, which are manmade composite materials having a negative index of refraction, to create a biconcave lens architecture.
Abstract: An efficient, low-loss, low sidelobe, high dynamic range phased-array radar antenna system is disclosed that uses metamaterials, which are manmade composite materials having a negative index of refraction, to create a biconcave lens architecture (instead of the aforementioned biconvex lens) for focusing the microwaves transmitted by the antenna. Accordingly, the sidelobes of the antenna are reduced. Attenuation across microstrip transmission lines may be reduced by using low loss transmission lines that are suspended above a ground plane a predetermined distance in a way such they are not in contact with a solid substrate. By suspending the microstrip transmission lines in this manner, dielectric signal loss is reduced significantly, thus resulting in a less-attenuated signal at its destination.

243 citations

Journal ArticleDOI
TL;DR: A scalable transmitter architecture for power generation and beam-steering at THz frequencies using a centralized frequency reference, sub-harmonic signal distribution, and local phase control is presented using a novel method called distributed active radiation.
Abstract: In this paper, we present a scalable transmitter architecture for power generation and beam-steering at THz frequencies using a centralized frequency reference, sub-harmonic signal distribution, and local phase control. The power generation and radiator core is based on a novel method called distributed active radiation, which enables high conversion efficiency from DC to radiated terahertz power above fmax of a technology. The design evolution of the distributed active radiator (DAR) follows from an inverse design approach, where metal surface currents at different harmonics are formulated in the silicon chip for the desired electromagnetic field profiles. Circuits and passives are then designed conjointly to synthesize and control the surface currents. The DAR consists of a self-oscillating active electromagnetic structure, comprising of two loops which sustain out-of-phase currents at the fundamental frequency and in-phase currents at the second harmonic. The fundamental signal, thus gets, spatially filtered, while the second harmonic is radiated selectively, thereby consolidating signal generation, frequency multiplication, radiation of desired harmonic and filtration of undesired harmonics simultaneously in a small silicon footprint. A two-dimensional 4×4 radiating array implemented in 45 nm SOI CMOS (without high-resistivity substrate) radiates with an EIRP of +9.4 dBm at 0.28 THz and beam-steers in 2D over 80° in both azimuth and elevation. The chip occupies 2.7 mm × 2.7 mm and dissipates 820 mW of DC power. To the best of the authors' knowledge, this is the first reported integrated beam-scanning array at THz frequencies in silicon.

243 citations

Journal ArticleDOI
H. Kamoda, T. Iwasaki, J. Tsumochi, T. Kuki, Osamu Hashimoto1 
TL;DR: In this paper, a large electronically reconfigurable reflectarray antenna that has 160 × 160 reflecting elements was designed, fabricated, and evaluated so that it could be applied to a millimeter-wave imaging system operating in the 60 GHz band.
Abstract: A large electronically reconfigurable reflectarray antenna that has 160 × 160 reflecting elements was designed, fabricated, and evaluated so that it could be applied to a millimeter-wave imaging system operating in the 60-GHz band. To make it feasible to construct such a large reflectarray, the reflecting element structure had to be simple and easily controlled; therefore, a reflecting element consisting of a microstrip patch and a single-bit digital phase shifter using a p-i-n diode was employed. A large reflectarray antenna was fabricated using the reflecting elements. The measured radiation patterns and antenna gain were in good agreement with those that were calculated. Furthermore, the near-field beam focusing capabilities, which was required to image near-field objects, were also verified through an experiment. Finally, the response time for beamforming was measured, which was far less than the system requirements.

242 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023373
20221,052
2021661
2020979
20191,266
20181,066