Single element and linear array PZT ultrasound biomicroscopy transducers

2002 ◽  
Author(s):  
M. Lukacs ◽  
M. Sayer ◽  
S. Foster
Keyword(s):  
Linear Array ◽  
Ultrasound Biomicroscopy ◽  
Single Element

scholarly journals High gain 5G MIMO antenna for mobile base station

2019 ◽  
Vol 9 (1) ◽  
pp. 468 ◽  
Author(s):  
Yusnita Rahayu ◽  
Indah Permata Sari ◽  
Dara Incam Ramadhan ◽  
Razali Ngah
Keyword(s):  
Linear Array ◽  
Multiple Input Multiple Output ◽  
High Gain ◽  
Base Station ◽  
Impedance Bandwidth ◽  
Single Element ◽  
Mimo Antenna ◽  
Input Multiple Output ◽  
Mobile Base Station ◽  
Mobile Base

This article presented a millimeter wave antenna which operated at 38 GHz for 5G mobile base station. The MIMO (Multiple Input Multiple Output) antenna consisted of 1x10 linear array configurations. The proposed antenna’s size was 88 x 98 mm^2  and printed on 1.575 mm-thick Rogers Duroid 5880 subsrate with dielectric constant of ε_r= 2.2 and loss tangent (tanδ) of 0.0009. The antenna array covered along the azimuth plane to provide the coverage to the users in omnidirection. The simulated results showed that the single element antenna had the reflection coefficient (S11) of -59 dB, less than -10 dB in the frequency range of 35.5 - 39.6 GHz. More than 4.1 GHz of impedance bandwidth was obtained. The gain of the antenna linear array was 17.8 dBi while the suppression of the side lobes was -2.7 dB.  It showed a high array gain throughout the impedance bandwidth with overall of VSWR were below 1.0646. It designed using CST microwave studio.

Pyroelectric single-element and linear-array sensors based on P(VDF/TrFE) thin films

1994 ◽  
Vol 45 (3) ◽  
pp. 209-218 ◽  
Author(s):  
Reinhard Köhler ◽  
Norbert Neumann ◽  
Günter Hofmann
Keyword(s):  
Thin Films ◽  
Linear Array ◽  
Single Element

Solar Spectrum Splitting Parallel Junction High Efficiency Concentrating Photovoltaics

2012 ◽  
Vol 1391 ◽  
Author(s):  
Lirong Z. Broderick ◽  
Marco Stefancich ◽  
Dario Roncati ◽  
Brian R. Albert ◽  
Xing Sheng ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Linear Array ◽  
Low Cost ◽  
Spectral Band ◽  
Solar Spectrum ◽  
Optical Loss ◽  
Single Element ◽  
Si Substrate ◽  
Spectrum Splitting

ABSTRACTA compact, single element concentrator comprising a near linear array of prisms has been designed to simultaneously split and concentrate the solar spectrum. Laterally aligned solar cells with different bandgaps are devised to be fabricated on a common Si substrate, with each cell absorbing a different spectral band optimized for highest overall power conversion efficiency. Epitaxial Ge on Si is used as a low cost virtual substrate for III-V materials growth. Assuming no optical loss for the prism concentrator, no shadowing and perfect carrier collection for the solar cells, simulations show that 39% efficiency can be achieved for a parallel four-junction (4PJ) InGaP-GaAs-Si-Ge cell under 200X concentration, and higher efficiency is possible with more junctions.

scholarly journals Implementation of a Rotational Ultrasound Biomicroscopy System Equipped with a High-Frequency Angled Needle Transducer — Ex Vivo Ultrasound Imaging of Porcine Ocular Posterior Tissues

2021 ◽  
Author(s):  
Tae-Hoon Bok ◽  
Juho Kim ◽  
Jinho Bae ◽  
Chong Hyun Lee ◽  
Dong-Guk Paeng
Keyword(s):  
Ultrasound Imaging ◽  
High Frequency ◽  
Ex Vivo ◽  
Focal Length ◽  
Ultrasound Biomicroscopy ◽  
Single Element ◽  
High Frequency Ultrasound ◽  
Scanning Angle ◽  
Distance Range ◽  
Minimal Incision

The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicroscopy (UBM) system equipped with a high-frequency angled needle transducer is designed and implemented in order to minimize the space required. It was applied to ex vivo ultrasound imaging of porcine posterior ocular tissues through a minimal incision hole of 1 mm in diameter. The retina and sclera for the one eye were visualized in the relative rotating angle range of 270° ~ 330° and at a distance range of 6 ~ 7 mm, whereas the tissues of the other eye were observed in relative angle range of 160° ~ 220° and at a distance range of 7.5 ~ 9 mm. The layer between retina and sclera seemed to be bent because the distance between the transducer tip and the layer was varied while the transducer was rotated. Certin features of the rotation system such as the optimal scanning angle, step angle and data length need to be improved for ensure higher accuracy and precision. Moreover, the focal length should be considered for the image quality. This implementation represents the first report of a rotational scanning UBM system.

scholarly journals Implementation of a Rotational Ultrasound Biomicroscopy System Equipped with a High-Frequency Angled Needle Transducer — Ex Vivo Ultrasound Imaging of Porcine Ocular Posterior Tissues

2021 ◽  
Author(s):  
Tae-Hoon Bok ◽  
Juho Kim ◽  
Jinho Bae ◽  
Chong Hyun Lee ◽  
Dong-Guk Paeng
Keyword(s):  
Ultrasound Imaging ◽  
High Frequency ◽  
Ex Vivo ◽  
Focal Length ◽  
Ultrasound Biomicroscopy ◽  
Single Element ◽  
High Frequency Ultrasound ◽  
Scanning Angle ◽  
Distance Range ◽  
Minimal Incision

The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicroscopy (UBM) system equipped with a high-frequency angled needle transducer is designed and implemented in order to minimize the space required. It was applied to ex vivo ultrasound imaging of porcine posterior ocular tissues through a minimal incision hole of 1 mm in diameter. The retina and sclera for the one eye were visualized in the relative rotating angle range of 270° ~ 330° and at a distance range of 6 ~ 7 mm, whereas the tissues of the other eye were observed in relative angle range of 160° ~ 220° and at a distance range of 7.5 ~ 9 mm. The layer between retina and sclera seemed to be bent because the distance between the transducer tip and the layer was varied while the transducer was rotated. Certin features of the rotation system such as the optimal scanning angle, step angle and data length need to be improved for ensure higher accuracy and precision. Moreover, the focal length should be considered for the image quality. This implementation represents the first report of a rotational scanning UBM system.

Circular Complementary Split Ring Resonator Rotation for Linear Array Millimeter Wave Microstrip Patch Antenna

2021 ◽  
Vol 20 (3) ◽  
pp. 43-47
Author(s):  
Norsaidah Muhamad Nadzir ◽  
Mohamad Kamal A. Rahim ◽  
Noor Asniza Murad ◽  
Mohamed Himdi ◽  
Osman Ayop
Keyword(s):  
Millimeter Wave ◽  
Linear Array ◽  
Ground Plane ◽  
Split Ring Resonator ◽  
Dual Band ◽  
Single Element ◽  
Horizontal Polarization ◽  
Angular Rotation ◽  
Complementary Split Ring Resonator ◽  
Multiple Frequencies

This paper proposes multiple linear array millimeter wave MPAs that could operate at various frequencies depending on the angular rotation of the CSRR structure. The main contribution of this work is the range of frequencies of the linear array MPA found when the position of the CSRR structure is changed angularly. This is achieved by positioning the CSRR structure on the ground plane of the MPA and rotate it to an incremental of 22.5°. Computer Simulation Technology software is used to simulate the antenna designs. The performance of the antenna is evaluated against the single element millimeter wave MPA with similar angular rotation to the CSRR structure. The reflection coefficient graph shows at 0° rotation, the antenna has dual band performance at 26 GHz and 28 GHz. At 22.5° and 45° CSRR structure rotation, the antenna shows triple band performance with different operational frequencies and different polarization depending on the frequencies. Finally, at 67.5° CSRR structure rotation, the antenna now is operational only at 20 GHz frequency with horizontal polarization performance. Plus, the results between the single element MPA with circular CSSRR and the linear array MPA with circular CSRR shows similar behavior in which the rotation of the CSRR did not affect the antenna differently even with an increase of the number of elements. The millimeter wave MPA with CSRR angular rotation can be utilized in various applications as it covers multiple frequencies depending on the angle of rotation of the CSRR structure.

Preparation and Pyroelectric Properties of La-Modified PbTiO8 Thin Films by Rf-Magnetron Sputtering

1996 ◽  
Vol 433 ◽  
Author(s):  
T. Kamada ◽  
R. Takayama ◽  
A. Tomozawa ◽  
S. Fujii ◽  
K. IIJIMA ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Linear Array ◽  
Rf Magnetron Sputtering ◽  
Fast Response ◽  
Pyroelectric Coefficient ◽  
Single Element ◽  
Air Conditioner ◽  
Pyroelectric Properties ◽  
Ir Sensors

AbstractHigh-quality La-modified PbTiO3 (Pb1−xLaxTi1−x/4O3; PLT) thin films were prepared by an rf-magnetron sputtering method. In this method, intermittent deposition was realized by periodical repetition of deposition and nondeposition processes. This deposition was found to enhance the horizontal grain growth of the films. The PLT thin films exhibit the phenomena named “self-polarization” and have high pyroelectric properties (pyroelectric coefficient γ of 5.0×10−8C/cm2K and low dielectric constant εr of 185) without a poling treatment. It was interestingly found that this self-polarization of the PLT thin films depends on the substrate temperature (Ts) and is based on a fairly small difference of the film composition (Pb/Ti). The pyroelectric properties were improved by means of addition of Mg to the PLT thin films. These thin films are expected to offer suitable materials for pyroelectric infrared (IR) sensors. High sensitive pyroelectric IR sensors (single element type and linear array type) were fabricated by using the PLT (x=0. 1) thin films with the new structures and the device processes. The sensors have remarkably high specific detectivity D* of 3.5×108 cm. Hz1/2/W and very fast response. A new compact IR sensing system using the linear array sensor (8 elements) has been developed for a new type of room air-conditioner.

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