A Novel Planar Mode-Transducing Antenna Based on Metal-Only Transmitarray Surfaces

2019 ◽  
Vol 67 (6) ◽  
pp. 3762-3773 ◽  
Author(s):  
Jianing Zhao ◽  
Tianming Li ◽  
Hao Li ◽  
Xiaoguang Yang ◽  
Yihong Zhou ◽  
...  
Keyword(s):  
2016 ◽  
Vol 848 ◽  
pp. 339-343
Author(s):  
Xiao Kun Zhao ◽  
Bo Ping Zhang ◽  
Lei Zhao ◽  
Li Feng Zhu

The modified behavior of the phase transition temperatures (TO-T and/or TC) between orthorhombic (O), tetragonal (T) and cubic (C) that caused by doping Sb5+ in (Li0.052Na0.493K0.455)(Nb1-xSbx)O3 (LNKNSx) ceramics was reported in the present investigation. The results show that differing from the insensitive TO-T to the Sb5+ content, TC splits into two peaks TCI and TCII when doping Sb5+. The decreased TCI by raising x may be ascribed to the Sb-rich grains and the settled TCII round 480 °C resulting from the Sb-lack ones. The enhanced piezoelectric coefficient d33 value of 263 pC/N and planar mode electromechanical coupling coefficient kp value of 42.5% at x=0.052 can be attributed to the polymorphic phase boundary (PPB) behavior with an appropriate ratio between T and O phases without any second phase.


2013 ◽  
Vol 479-480 ◽  
pp. 3-7
Author(s):  
Chun Huy Wang

In the present study, various quantities of Bi2O3were added into 0.98(Na0.5K0.5)NbO3-0.02Bi(Na0.93K0.07)TiO3(0.98NKN-0.02BNKT) ceramics. It was found that 0.98NKN-0.02BNKTwith the addition of 0~0.5 wt.% Bi2O3exhibit relatively good piezoelectric properties. For 0.98NKN-0.02BNKT ceramics, the electromechanical coupling coefficients of the planar modekpand the thickness modektreach 0.40 and 0.47,respectively. For 0.98NKN-0.02BNKT ceramics with the addition of 0.3 wt.% Bi2O3, the electromechanical coupling coefficients ofthe planar modekpand the thickness modektreach 0.50 and 0.53, respectively. It is obvious that 0.98NKN-0.02BNKT solid solution ceramics by adding low quantities of Bi2O3is one of the promising lead-free ceramics for electromechanical transducer applications.


2010 ◽  
Vol 434-435 ◽  
pp. 413-416 ◽  
Author(s):  
Chun Huy Wang

The 0.98(Na0.5K0.5)NbO3–0.02Ba(Zr0.04Ti0.96)O3 ceramics have been prepared following the conventional mixed oxide process. X-ray diffraction analysis revealed that, during sintering, all of the Ba(Zr0.04Ti0.96)O3 diffuses into the lattice of (Na0.5K0.5)NbO3 to form a solid solution, in which a orthorhombic phase with a perovskite structure was found In order to improve the sinterability of the ceramics, Bi2O3 additions were used as a sintering aid. The electromechanical coupling coefficients of the planar mode kp and the thickness mode kt reach 0.3 and 0.55, respectively, at the sintering of 1100oC for 5 h. For 0.98NKN-0.02BZT ceramics by doping 0.5 wt.% Bi2O3, the electromechanical coupling coefficients of the planar mode kp and the thickness mode kt reach 0.21 and 0.57, respectively. The ratio of thickness coupling coefficient to planar coupling coefficient is 2.7.


2013 ◽  
Vol 706-708 ◽  
pp. 1146-1149
Author(s):  
Hui Zhi Sun

Nanometer three Coordinate Measuring Machine (Naro-CMM) has got fast development especially in the advancement of modern technology. Platform is an important part of the Naro-CMM, paper puts forward a new way to drive platform. “Planar” mode is adopted, and the power module is designed based on L6234PD, the experimental results express that the positioning accuracy of the platform reaches nanometer accuracy. So the drive method satisfied the demand of this platform’s movement.


2007 ◽  
Vol 336-338 ◽  
pp. 224-227
Author(s):  
Ke Wang ◽  
Bo Ping Zhang ◽  
Jing Feng Li ◽  
Hong Jin Liu

Highly dense Na1-xKxNbO3 (x=0.2~0.8) ceramics were successfully prepared using spark plasma sintering (SPS) at temperature as low as 920°C. Solid solutions were formed during the composition range investigated. The piezoelectric constant and planar mode electromechanical coupling coefficient are significantly dependent on the Na/K ratio, with the maximum value of 148 pC/N and 38.9% at the composition Na0.5K0.5NbO3.


2011 ◽  
Vol 130-134 ◽  
pp. 883-886
Author(s):  
Chun Huy Wang

In this paper, the effects of Ta2O5addition on the electrical and physical properties of 0.98(Na0.5K0.5)NbO3-0.02(Na0.5Bi0.5)TiO3were investigated. The 0.98(Na0.5K0.5)NbO3-0.02(Na0.5Bi0.5)TiO3[0.98NKN-0.02NBT] ceramics with the addition of 0~0.5 wt% Ta2O5have been prepared following the conventional mixed oxide process. X-ray diffraction analysis revealed that, during sintering, all of the (Na0.5Bi0.5)TiO3diffuse into the lattice of (Na0.5K0.5)NbO3to form a solid solution, in which a orthorhombic phase with a perovskite structure was found. For 0.98NKN-0.02NBT ceramics by doping 0.1 wt% Ta2O5, the poled dielectric constant (K33T) is 1090. The electromechanical coupling coefficients of the planar modekpand the thickness modektreach 0.39 and 0.48, respectively. Our results show that 0.98NKN-0.02NBT with the addition of 0.1 wt% Ta2O5is a good lead-free piezoelectric ceramic.


2015 ◽  
Vol 1084 ◽  
pp. 460-463
Author(s):  
Anna Titskaya ◽  
Vladimir Chernov ◽  
Elena Slonimskaya ◽  
Ivan Sinilkin ◽  
Roman Zelchan

To study the diagnostic capabilities of planar breast scintigraphy and single photon emission computed tomography (SPECT) with 99mTc-MIBI in visualizing of breast tumors, 61 patients with a diagnosis of breast cancer were included in the study. The results showed that sensitivity of the planar mode in identifying primary breast tumors was 46%. The sensitivity of SPECT in detecting primary tumor was 93.4%. The sensitivity of the planar mode in visualization of nodal metastases was 44.8%, against 93.1% in SPECT. This study showed that SPECT has a high diagnostic efficiency in regard of visualization of small sized tumors, multicenter tumor growth, identifying space-occupying lesions on the background of modified breast tissue.


2011 ◽  
Vol 415-417 ◽  
pp. 1051-1054
Author(s):  
Chun Huy Wang

In the present study, various quantities of Bi2O3were added into 0.98(Na0.5Bi0.5)TiO3-0.02Ba(Sn0.08Ti0.92)O3(0.98NBT-0.02BST) ceramics. High-density samples were obtained through the addition of Bi2O3into 0.98NBT-0.02BST ceramic. It was found that 0.98NBT-0.02BST with the addition of 0~3.0 wt.% Bi2O3exhibit relatively good piezoelectric properties. For 0.98NBT-0.02BST ceramic with the addition of 2 wt.% Bi2O3, the electromechanical coupling coefficients of the planar mode kp and the thickness mode kt reach 0.12 and 0.61, respectively, at the sintering of 1100oC for 3 h. The ratio of thickness coupling coefficient to planar coupling coefficient is 5.1. It is obvious that 0.98NBT-0.02BST solid solution ceramic by adding low quantities of Bi2O3is one of the promising lead-free ceramics for high frequency electromechanical transducer applications.


1998 ◽  
Vol 72 (7) ◽  
pp. 858-860 ◽  
Author(s):  
S. H. Lee ◽  
H. Y. Kim ◽  
H. G. Galabova ◽  
D. W. Allender

2018 ◽  
Vol 99 (4) ◽  
pp. 184-190
Author(s):  
R. B. Amansakhedov ◽  
L. N. Lepekha ◽  
L. I. Dmitrieva ◽  
I. Yu. Andrievskaya ◽  
A. T. Sigaev ◽  
...  

Objective: to evaluate the X-ray radiological features of nontuberculous mycobacterial pulmonary disease (NTMPD) versus morphological findings.Material and methods. The investigation enrolled 37 patients, in whom the radiographic signs of dissemination were determined and various types of NTMPD were identified. The investigation was conducted on a Siemens Somatom Emotion 16 multislice computed tomography (MSCT) scanner using a high-resolution algorithm (Quick Time Virtual Reality). To clarify the activity of pathological changes in the thoracic organs, 16 (43.2%) patients underwent a radionuclide study with 99mTc-technetrile on a Nucline Spirit gamma camera in planar and single photon emission computed tomography modes.The diagnosis was verified by sputum smear microscopy and clinical laboratory and bronchologic examinations: bronchoalveolar lavage in 11 (29.7%) patients, various types of bronchial biopsies in 17 (46.0%), morphological examinations, and videoassisted thoracoscopic surgery for pulmonary resection in 9 (24.3%).Results. The dissemination foci in mycobacterial diseases were characterized by their location in the lung parenchyma with vascular and bronchial involvement and reactive changes in the pulmonary pleurae and intrathoracic lymph nodes (ITLN). In 92.7% of cases, the detected foci were predominantly centrilobular with endobronchial localization. Their contours were mixed with clear and fuzzy outlines in 98.7% of cases. In 70.3% of cases, the foci were asymmetrically localized mainly in the subpleural areas of the lung and 12.3% of cases were accompanied by reactive involvement of the visceral pleura.CT study revealed a tree-in-bud sign in 96.7% of cases, frosted glass in 10.2%, and mosaic perfusion in 13.2%. A more than 10-mm increase in ITLN was found in 11.7% of cases.In a number of cases, it was difficult to speak about the activity of the pathological process in the lung and ITLN, as shown by MSCT. In this case, a lung radionuclide study with 99mTc-technetrile was carried out in the planar mode. The degree of tracer accumulation, localization, and extent were analyzed in the planar mode.Conclusion. Thus, the CT typical signs of NTMPD are the asymmetric location of its foci with an endobronchial extension, peribronchovascular localization of foci; the presence of a CT tree-in-bud sign; and the slight involvement of the pulmonary pleurae in the process. 99mTs-technetril radionuclide study has established that the most active inflammatory process is located in the lung and the tracer accumulates in the pathologically altered lymph nodes.


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