Thermosensitive strontium titanate(SrTiO3)as a ferroelectric crystal with great tunability in microwave and terahertz band shows unparalleled potential value.Utilizing the thermal electromagnetic tunability to achieve...Thermosensitive strontium titanate(SrTiO3)as a ferroelectric crystal with great tunability in microwave and terahertz band shows unparalleled potential value.Utilizing the thermal electromagnetic tunability to achieve the intelligent manipulation,a thermal-tunable metamaterial with terahertz-band absorption based on SrTiO3 crystal was proposed in this paper.The absorbent metamaterial(AM)is formed by Floquet’s linear periodic arranged unit,which is composed of a metallic ground plane and embedded cross SrTiO3 material in rhombic metallic patch,and separated by FR-4 dielectric spacer.The broadband frequency tunability of AM was operated by changing the temperature.The permittivity of SrTiO3 was discussed in detail to illustrate how the reconfigurability with thermal transformation is generated.The numerical results show that the tunable broadband of the absorbent band has reached 90 GHz and the corresponding absorptivity is above 99% when the temperature increases from 280 K to 360 K.The resonance frequency will produce a blue-shift with the increase of the temperature.This paper presents a passive thermal-tunable metamaterial as a potential candidate for sensing,materials detection and frequency selective thermal emitters.展开更多
针对太赫兹频段高速移动场景,提出了一种参考信号方案——增强型离散傅里叶变换扩展正交频分复用(E DFT-s-OFDM)DMRS:将具有循环前缀(CP)和循环后缀(CS)的参考信号序列分割为首部和尾部参考信号序列,然后分别嵌入每个OFDM符号的尾部和...针对太赫兹频段高速移动场景,提出了一种参考信号方案——增强型离散傅里叶变换扩展正交频分复用(E DFT-s-OFDM)DMRS:将具有循环前缀(CP)和循环后缀(CS)的参考信号序列分割为首部和尾部参考信号序列,然后分别嵌入每个OFDM符号的尾部和首部。这种方案的优点在于,前一个OFDM符号的尾部和后一个OFDM符号的首部构成一个完整的参考信号序列,从而允许接收端在每个OFDM符号间隔内都能进行信道估计,提高了信道估计的精度和实时性。此外,相邻OFDM符号的首部和尾部参考信号序列相同,从而省去了每个OFDM符号的传统循环前缀(CP),提高了频谱效率。仿真结果表明,在太赫兹频段高速移动场景下,与5G NR DFT-s-OFDM波形的DMRS方案相比,该方案的信道估计更精确,通信系统的频谱效率更高。展开更多
基金National Natural Science Foundation of China(No.U1637212)National Defense Pre-research Foundation of China(No.61404130402)+1 种基金Fund for“1331 Project”Key Subject Construction of Shanxi ProvinceFund for Key Laboratory(No.61428050104)。
文摘Thermosensitive strontium titanate(SrTiO3)as a ferroelectric crystal with great tunability in microwave and terahertz band shows unparalleled potential value.Utilizing the thermal electromagnetic tunability to achieve the intelligent manipulation,a thermal-tunable metamaterial with terahertz-band absorption based on SrTiO3 crystal was proposed in this paper.The absorbent metamaterial(AM)is formed by Floquet’s linear periodic arranged unit,which is composed of a metallic ground plane and embedded cross SrTiO3 material in rhombic metallic patch,and separated by FR-4 dielectric spacer.The broadband frequency tunability of AM was operated by changing the temperature.The permittivity of SrTiO3 was discussed in detail to illustrate how the reconfigurability with thermal transformation is generated.The numerical results show that the tunable broadband of the absorbent band has reached 90 GHz and the corresponding absorptivity is above 99% when the temperature increases from 280 K to 360 K.The resonance frequency will produce a blue-shift with the increase of the temperature.This paper presents a passive thermal-tunable metamaterial as a potential candidate for sensing,materials detection and frequency selective thermal emitters.
文摘针对太赫兹频段高速移动场景,提出了一种参考信号方案——增强型离散傅里叶变换扩展正交频分复用(E DFT-s-OFDM)DMRS:将具有循环前缀(CP)和循环后缀(CS)的参考信号序列分割为首部和尾部参考信号序列,然后分别嵌入每个OFDM符号的尾部和首部。这种方案的优点在于,前一个OFDM符号的尾部和后一个OFDM符号的首部构成一个完整的参考信号序列,从而允许接收端在每个OFDM符号间隔内都能进行信道估计,提高了信道估计的精度和实时性。此外,相邻OFDM符号的首部和尾部参考信号序列相同,从而省去了每个OFDM符号的传统循环前缀(CP),提高了频谱效率。仿真结果表明,在太赫兹频段高速移动场景下,与5G NR DFT-s-OFDM波形的DMRS方案相比,该方案的信道估计更精确,通信系统的频谱效率更高。
