Future communications will provide higher transmission rates and higher operating frequencies.In addition,agile beam tracking will be an inevitable trend in technology development.The terahertz retrodirective antenna ...Future communications will provide higher transmission rates and higher operating frequencies.In addition,agile beam tracking will be an inevitable trend in technology development.The terahertz retrodirective antenna array proposed and discussed in this paper can be a better solution for agile beam tracking.The array receives a 40-GHz navigation signal and accurately retransmits a 120-GHz beam in the direction of the arrival wave.Simulation results indicate that the proposed array with a stacked sandwich structure has realized the tracking of the received wave.The scanning radiation pattern shows that the array gain is 23.87 d B at 19.9°when the incident angle is 20°with a relative error of only 0.5%,meaning that there is a lateral error of only 8.7 m at a transmission distance of 5 km.展开更多
Transmission spectroscopy of two Nb double superconducting split-ring samples with different thicknesses on MgO substrates was measured by a continuous Tera-Hertz spectrometer.The transmission curves of two different ...Transmission spectroscopy of two Nb double superconducting split-ring samples with different thicknesses on MgO substrates was measured by a continuous Tera-Hertz spectrometer.The transmission curves of two different samples with the thicknesses of 50 and 150 nm at 7.5 K show dips at 480,545 GHz,respectively,which origin from the different capacities and inductances of the samples.For the sample of 50 nm,the dip shifts to lower frequency,also decreases in depth and increases in width with temperature or field increasing below T c of Nb film,while the sample of 150 nm does not show such a phenomenon.This thickness-dependent transmission behavior is due to the kinetic inductance and conductivity change of superfluid electrons in Nb film and may suggest a practical tunable THz filter based on the thinner samples.展开更多
基金Project supported by the National Key R&D Program of China(No.2018YFB1801505)the National Natural Science Foundation of China(Nos.61527805 and 61731001).
文摘Future communications will provide higher transmission rates and higher operating frequencies.In addition,agile beam tracking will be an inevitable trend in technology development.The terahertz retrodirective antenna array proposed and discussed in this paper can be a better solution for agile beam tracking.The array receives a 40-GHz navigation signal and accurately retransmits a 120-GHz beam in the direction of the arrival wave.Simulation results indicate that the proposed array with a stacked sandwich structure has realized the tracking of the received wave.The scanning radiation pattern shows that the array gain is 23.87 d B at 19.9°when the incident angle is 20°with a relative error of only 0.5%,meaning that there is a lateral error of only 8.7 m at a transmission distance of 5 km.
基金supported by the Science Foundation of the Chinese Academy of Sciences (Grant No.KJCX2-SW-W20)the National Basic Research Program of China (Grant No.2011CB921702)
文摘Transmission spectroscopy of two Nb double superconducting split-ring samples with different thicknesses on MgO substrates was measured by a continuous Tera-Hertz spectrometer.The transmission curves of two different samples with the thicknesses of 50 and 150 nm at 7.5 K show dips at 480,545 GHz,respectively,which origin from the different capacities and inductances of the samples.For the sample of 50 nm,the dip shifts to lower frequency,also decreases in depth and increases in width with temperature or field increasing below T c of Nb film,while the sample of 150 nm does not show such a phenomenon.This thickness-dependent transmission behavior is due to the kinetic inductance and conductivity change of superfluid electrons in Nb film and may suggest a practical tunable THz filter based on the thinner samples.
