The Experts below are selected from a list of 47187 Experts worldwide ranked by ideXlab platform
Dao Ngoc Chien - One of the best experts on this subject based on the ideXlab platform.
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design of compact 4 4 uwb mimo antenna with wlan band rejection
International Journal of Antennas and Propagation, 2014Co-Authors: Nguyen Khac Kiem, Huynh Nguyen Bao Phuong, Dao Ngoc ChienAbstract:A compact 4 × 4 UWB-MIMO antenna with rejected WLAN band employing an electromagnetic bandgap (EBG) structure is presented in this paper. The MIMO antenna is electrically small (60 mm × 60 mm), printed on a FR4_epoxy substrate with the dielectric constant of 4.4 and a thickness of 1.6 mm. A mushroom-like EBG structure is used to reject the WLAN frequency at 5.5 GHz. In order to reduce the mutual coupling of the antenna elements, a stub structure acting as a bandstop filter is inserted to suppress the effect of the surface current between elements of the proposed antenna. The final design of the MIMO antenna satisfies the return Loss Requirement of less than −10 dB in a bandwidth ranging from 2.73 GHz to 10.68 GHz, which entirely covers UWB frequency band, which is allocated from 3.1 to 10.6 GHz. The antenna also exhibits a WLAN band-notched performance at the frequency band of 5.36–6.34 GHz while the values of all isolation coefficients are below −15 dB and the correlation coefficient of MIMO antenna is less than −28 dB over the UWB range. A good agreement between simulation and measurement is shown in this context.
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Design of compact 4 × 4 UWB-MIMO antenna with WLAN band rejection
International Journal of Antennas and Propagation, 2014Co-Authors: Nguyen Khac Kiem, Huynh Nguyen Bao Phuong, Dao Ngoc ChienAbstract:A compact 4 × 4 UWB-MIMO antenna with rejected WLAN band employing an electromagnetic bandgap (EBG) structure is presented in this paper. The MIMO antenna is electrically small (60 mm × 60 mm), printed on a FR4_epoxy substrate with the dielectric constant of 4.4 and a thickness of 1.6 mm. A mushroom-like EBG structure is used to reject the WLAN frequency at 5.5 GHz. In order to reduce the mutual coupling of the antenna elements, a stub structure acting as a bandstop filter is inserted to suppress the effect of the surface current between elements of the proposed antenna. The final design of the MIMO antenna satisfies the return Loss Requirement of less than −10 dB in a bandwidth ranging from 2.73 GHz to 10.68 GHz, which entirely covers UWB frequency band, which is allocated from 3.1 to 10.6 GHz. The antenna also exhibits a WLAN band-notched performance at the frequency band of 5.36–6.34 GHz while the values of all isolation coefficients are below −15 dB and the correlation coefficient of MIMO antenna is less than −28 dB over the UWB range. A good agreement between simulation and measurement is shown in this context.
Benjamin D. Braaten - One of the best experts on this subject based on the ideXlab platform.
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compact 4 4 uwb mimo antenna with wlan band rejected operation
Electronics Letters, 2015Co-Authors: Sajid M Asif, Adnan Iftikhar, Bilal Ijaz, Benjamin D. BraatenAbstract:A compact planar UWB-MIMO antenna array with WLAN band rejection is presented. The array consists of four monopole radiators and a common ground plane. These monopoles are placed in such a way that the polarisation diversity of nearly placed radiators is exploited, resulting in high isolation. The proposed MIMO antenna array is electrically small (50 × 39.8 mm2), printed on a low Loss 1.524 mm thick Rogers TMM4 laminate with a dielectric constant of 4.5 and a Loss tangent of 0.002. A band-stop design was inserted on the ground plane to behave similar to a LC band-stop filter and reject the WLAN band. Simulation and measurement results satisfy the return Loss Requirement of better than 10 dB and isolation better than 17 dB over the entire 2.7–5.1 and 5.9–12 GHz bandwidths.
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A 4 element compact Ultra-Wideband MIMO antenna array
Antennas and Propagation & USNC/URSI National Radio Science Meeting, 2015 IEEE International Symposium on, 2015Co-Authors: Muhammad Saeed Khan, Sajid M Asif, Adnan Iftikhar, Antonio-daniele Capobianco, Benjamin D. BraatenAbstract:In this paper, a compact planar Ultra-Wideband (UWB) antenna array with 4 monopole radiators is presented. To enhance the isolation, polarization of nearly placed elements is exploited. The proposed MIMO antenna array is electrically small 50 × 39.8 mm2, printed on a low Loss 1.524 mm thick Rogers TMM4 laminate with a dielectric constant of 4.5 and a Loss tangent of 0.002. Simulation in HFSS and printed prototype results satisfy the return Loss Requirement of better than 10 dB and isolation better than 17 dB on the entire 2.5 to 12 GHz bandwidth. The calculated envelope correlation value of less than 0.03 and the compactness of the proposed antenna array makes it suitable for small portable handheld devices.
Nguyen Khac Kiem - One of the best experts on this subject based on the ideXlab platform.
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design of compact 4 4 uwb mimo antenna with wlan band rejection
International Journal of Antennas and Propagation, 2014Co-Authors: Nguyen Khac Kiem, Huynh Nguyen Bao Phuong, Dao Ngoc ChienAbstract:A compact 4 × 4 UWB-MIMO antenna with rejected WLAN band employing an electromagnetic bandgap (EBG) structure is presented in this paper. The MIMO antenna is electrically small (60 mm × 60 mm), printed on a FR4_epoxy substrate with the dielectric constant of 4.4 and a thickness of 1.6 mm. A mushroom-like EBG structure is used to reject the WLAN frequency at 5.5 GHz. In order to reduce the mutual coupling of the antenna elements, a stub structure acting as a bandstop filter is inserted to suppress the effect of the surface current between elements of the proposed antenna. The final design of the MIMO antenna satisfies the return Loss Requirement of less than −10 dB in a bandwidth ranging from 2.73 GHz to 10.68 GHz, which entirely covers UWB frequency band, which is allocated from 3.1 to 10.6 GHz. The antenna also exhibits a WLAN band-notched performance at the frequency band of 5.36–6.34 GHz while the values of all isolation coefficients are below −15 dB and the correlation coefficient of MIMO antenna is less than −28 dB over the UWB range. A good agreement between simulation and measurement is shown in this context.
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Design of compact 4 × 4 UWB-MIMO antenna with WLAN band rejection
International Journal of Antennas and Propagation, 2014Co-Authors: Nguyen Khac Kiem, Huynh Nguyen Bao Phuong, Dao Ngoc ChienAbstract:A compact 4 × 4 UWB-MIMO antenna with rejected WLAN band employing an electromagnetic bandgap (EBG) structure is presented in this paper. The MIMO antenna is electrically small (60 mm × 60 mm), printed on a FR4_epoxy substrate with the dielectric constant of 4.4 and a thickness of 1.6 mm. A mushroom-like EBG structure is used to reject the WLAN frequency at 5.5 GHz. In order to reduce the mutual coupling of the antenna elements, a stub structure acting as a bandstop filter is inserted to suppress the effect of the surface current between elements of the proposed antenna. The final design of the MIMO antenna satisfies the return Loss Requirement of less than −10 dB in a bandwidth ranging from 2.73 GHz to 10.68 GHz, which entirely covers UWB frequency band, which is allocated from 3.1 to 10.6 GHz. The antenna also exhibits a WLAN band-notched performance at the frequency band of 5.36–6.34 GHz while the values of all isolation coefficients are below −15 dB and the correlation coefficient of MIMO antenna is less than −28 dB over the UWB range. A good agreement between simulation and measurement is shown in this context.
Glen P. Kenny - One of the best experts on this subject based on the ideXlab platform.
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revisiting the influence of individual factors on heat exchange during exercise in dry heat using direct calorimetry
Experimental Physiology, 2019Co-Authors: Sean R. Notley, Dallon T. Lamarche, Robert D. Meade, Andreas D. Flouris, Glen P. KennyAbstract:NEW FINDINGS What is the central question of this study? The aim was to identify the greatest contributor(s) to the variation in whole-body heat exchange, as assessed using direct calorimetry, among young men and women with heterogeneous characteristics during exercise at increasing metabolic heat production rates in dry heat. What is the main finding and its importance? The evaporative heat Loss Requirement, body morphology and aerobic fitness made the greatest contributions to the individual variation in evaporative and dry heat exchange, with the variance explained being exercise intensity dependent. These findings provide a foundation on which to build our ability to explain the individual variation in heat exchange during exercise-induced heat stress. ABSTRACT Numerous individual factors (e.g. fitness, sex, body morphology) are known to independently modulate heat exchange during exercise in the heat. However, in our view, the individual factor(s) making the greatest contribution to the variation in heat exchange among men and women remains poorly understood, despite several studies. We therefore sought to revisit this question by assessing whole-body dry and evaporative heat exchange using direct calorimetry in a heterogeneous sample of 100 young men (n = 57) and women (n = 43). Participants performed three 30 min bouts of cycling at very light (men/women; 300/250 W), light (400/325 W) and moderate (500/400 W) metabolic heat production rates, separated by a 15 min recovery, in dry heat (40°C, ∼12% relative humidity). Positive associations were observed between the evaporative heat Loss Requirement (metabolic heat production ± dry heat exchange) and evaporative heat Loss (all P < 0.01), especially during moderate exercise (men, r = 0.62; women, r = 0.82), which explained 19-67% of individual variation. Peak aerobic power (in millilitres per kilogram per minute) was also positively related to evaporative heat Loss in both sexes, albeit only during light and moderate exercise (r = 0.33-0.43; all P < 0.05), explaining a further 5-9% of individual variation. Dry heat exchange shared negative associations with body mass and surface area during all exercise bouts in both sexes (r = -0.29 to -0.55; all P < 0.05), explaining 9-30% of individual variation. We therefore demonstrate that the evaporative heat Loss Requirement, peak aerobic power and body morphology are the greatest contributors to the variation in whole-body heat exchange among young men and women exercising in dry heat, with the strength of those relationships being heat-load dependent.
Andreas D. Flouris - One of the best experts on this subject based on the ideXlab platform.
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revisiting the influence of individual factors on heat exchange during exercise in dry heat using direct calorimetry
Experimental Physiology, 2019Co-Authors: Sean R. Notley, Dallon T. Lamarche, Robert D. Meade, Andreas D. Flouris, Glen P. KennyAbstract:NEW FINDINGS What is the central question of this study? The aim was to identify the greatest contributor(s) to the variation in whole-body heat exchange, as assessed using direct calorimetry, among young men and women with heterogeneous characteristics during exercise at increasing metabolic heat production rates in dry heat. What is the main finding and its importance? The evaporative heat Loss Requirement, body morphology and aerobic fitness made the greatest contributions to the individual variation in evaporative and dry heat exchange, with the variance explained being exercise intensity dependent. These findings provide a foundation on which to build our ability to explain the individual variation in heat exchange during exercise-induced heat stress. ABSTRACT Numerous individual factors (e.g. fitness, sex, body morphology) are known to independently modulate heat exchange during exercise in the heat. However, in our view, the individual factor(s) making the greatest contribution to the variation in heat exchange among men and women remains poorly understood, despite several studies. We therefore sought to revisit this question by assessing whole-body dry and evaporative heat exchange using direct calorimetry in a heterogeneous sample of 100 young men (n = 57) and women (n = 43). Participants performed three 30 min bouts of cycling at very light (men/women; 300/250 W), light (400/325 W) and moderate (500/400 W) metabolic heat production rates, separated by a 15 min recovery, in dry heat (40°C, ∼12% relative humidity). Positive associations were observed between the evaporative heat Loss Requirement (metabolic heat production ± dry heat exchange) and evaporative heat Loss (all P < 0.01), especially during moderate exercise (men, r = 0.62; women, r = 0.82), which explained 19-67% of individual variation. Peak aerobic power (in millilitres per kilogram per minute) was also positively related to evaporative heat Loss in both sexes, albeit only during light and moderate exercise (r = 0.33-0.43; all P < 0.05), explaining a further 5-9% of individual variation. Dry heat exchange shared negative associations with body mass and surface area during all exercise bouts in both sexes (r = -0.29 to -0.55; all P < 0.05), explaining 9-30% of individual variation. We therefore demonstrate that the evaporative heat Loss Requirement, peak aerobic power and body morphology are the greatest contributors to the variation in whole-body heat exchange among young men and women exercising in dry heat, with the strength of those relationships being heat-load dependent.
