Bulk Acoustic Wave(BAW)filters find applications in radio frequency(RF)communication systems for Wi-Fi,3G,4G,and 5G networks.In the beyond-5G(potential 6G)era,high-frequency bands(>8 GHz)are expected to require res...Bulk Acoustic Wave(BAW)filters find applications in radio frequency(RF)communication systems for Wi-Fi,3G,4G,and 5G networks.In the beyond-5G(potential 6G)era,high-frequency bands(>8 GHz)are expected to require resonators with high-quality factor(Q)and electromechanical coupling(k_(t)^(2))to form filters with low insertion loss and high selectivity.However,both the Q and k_(t)^(2)of resonator devices formed in traditional uniform polarization piezoelectric films of aluminum nitride(AlN)and aluminum scandium nitride(AlScN)decrease when scaled beyond 8 GHz.In this work,we utilized 4-layer AlScN periodically poled piezoelectric films(P3F)to construct high-frequency(~17–18 GHz)resonators and filters.The resonator performance is studied over a range of device geometries,with the best resonator achieving a k_(t)^(2)of 11.8%and a Qp of 236.6 at the parallel resonance frequency(f_(p))of 17.9 GHz.These resulting figures-of-merit are(FoM_(1)=k_(t)^(2)Qp and FoM_(2)=f_(p)FoM_(1)×10^(-9))27.9 and 500,respectively.These and the k_(t)^(2)are significantly higher than previously reported AlN/AlScN-based resonators operating at similar frequencies.Fabricated 3-element and 6-element filters formed from these resonators demonstrated low insertion losses(IL)of 1.86 and 3.25 dB,and−3 dB bandwidths(BW)of 680 MHz(fractional BW of 3.9%)and 590 MHz(fractional BW of 3.3%)at a~17.4 GHz center frequency.The 3-element and 6-element filters achieved excellent linearity with in-band input third-order intercept point(IIP3)values of+36 and+40 dBm,respectively,which are significantly higher than previously reported acoustic filters operating at similar frequencies.展开更多
Shape morphing is a critical aptitude for the survival of organisms and is determined by anisotropic tissue composition and directional orientation of micro-and nanostructures within cell walls,resulting in diferent s...Shape morphing is a critical aptitude for the survival of organisms and is determined by anisotropic tissue composition and directional orientation of micro-and nanostructures within cell walls,resulting in diferent swelling behaviors.Recent eforts have been dedicated to mimicking the behaviors that nature has perfected over billions of years.We present a robust strategy for preparing 3D periodically patterned single-component sodium alginate hydrogel sheets cross-linked with Ca^(2+)ions,which can reversibly deform and be retained into various desirable inside-out shapes as triggered by biocompatible ions(Na^(+)/Ca^(2+)).By changing the orientations of the patterned microchannels or triggering with Na^(+)/Ca^(2+)ions,various 3D twisting,tubular,and plantinspired architectures can be facilely programmed.Not only can the transformation recover their initial shapes reversibly,but also it can keep the designated shapes without continuous stimuli.Tese inside-out 3D reversible ion-triggered hydrogel transformations shall inspire more attractive applications in tissue engineering,biomedical devices,and sof robotics felds.展开更多
文摘Bulk Acoustic Wave(BAW)filters find applications in radio frequency(RF)communication systems for Wi-Fi,3G,4G,and 5G networks.In the beyond-5G(potential 6G)era,high-frequency bands(>8 GHz)are expected to require resonators with high-quality factor(Q)and electromechanical coupling(k_(t)^(2))to form filters with low insertion loss and high selectivity.However,both the Q and k_(t)^(2)of resonator devices formed in traditional uniform polarization piezoelectric films of aluminum nitride(AlN)and aluminum scandium nitride(AlScN)decrease when scaled beyond 8 GHz.In this work,we utilized 4-layer AlScN periodically poled piezoelectric films(P3F)to construct high-frequency(~17–18 GHz)resonators and filters.The resonator performance is studied over a range of device geometries,with the best resonator achieving a k_(t)^(2)of 11.8%and a Qp of 236.6 at the parallel resonance frequency(f_(p))of 17.9 GHz.These resulting figures-of-merit are(FoM_(1)=k_(t)^(2)Qp and FoM_(2)=f_(p)FoM_(1)×10^(-9))27.9 and 500,respectively.These and the k_(t)^(2)are significantly higher than previously reported AlN/AlScN-based resonators operating at similar frequencies.Fabricated 3-element and 6-element filters formed from these resonators demonstrated low insertion losses(IL)of 1.86 and 3.25 dB,and−3 dB bandwidths(BW)of 680 MHz(fractional BW of 3.9%)and 590 MHz(fractional BW of 3.3%)at a~17.4 GHz center frequency.The 3-element and 6-element filters achieved excellent linearity with in-band input third-order intercept point(IIP3)values of+36 and+40 dBm,respectively,which are significantly higher than previously reported acoustic filters operating at similar frequencies.
基金We are indebted to Dr.Massimiliano Galluzzi for performing AFM analysis of the samples.This work was supported by the National Key R&D Program of China(2017YFA0701303,2016YFA0201001)National Natural Science Foundation of China(21404116)+3 种基金the Youth Innovation Promotion Association of CAS,CAS Key Laboratory of Health Informatics,Shenzhen Institutes of Advanced Technology,Special Support Project for Outstanding Young Scholars of Guangdong Province(2015TQ01R292)Guangdong-Hong Kong Technology Cooperation Funding(2017A050506040)Shenzhen Science and Technology Innovation Committee(JCYJ20150316144521974,JCYJ20170818161757684,JCYJ2017-0413152640731)Shenzhen Peacock Plan.
文摘Shape morphing is a critical aptitude for the survival of organisms and is determined by anisotropic tissue composition and directional orientation of micro-and nanostructures within cell walls,resulting in diferent swelling behaviors.Recent eforts have been dedicated to mimicking the behaviors that nature has perfected over billions of years.We present a robust strategy for preparing 3D periodically patterned single-component sodium alginate hydrogel sheets cross-linked with Ca^(2+)ions,which can reversibly deform and be retained into various desirable inside-out shapes as triggered by biocompatible ions(Na^(+)/Ca^(2+)).By changing the orientations of the patterned microchannels or triggering with Na^(+)/Ca^(2+)ions,various 3D twisting,tubular,and plantinspired architectures can be facilely programmed.Not only can the transformation recover their initial shapes reversibly,but also it can keep the designated shapes without continuous stimuli.Tese inside-out 3D reversible ion-triggered hydrogel transformations shall inspire more attractive applications in tissue engineering,biomedical devices,and sof robotics felds.
