Over the next decade,Very High-Throughput Satellite (VHTS) will bring enough capacity to serve high speed internet and in-flight connectivity markets at scale,offering fiber-like services both in terms of price and sp...Over the next decade,Very High-Throughput Satellite (VHTS) will bring enough capacity to serve high speed internet and in-flight connectivity markets at scale,offering fiber-like services both in terms of price and speed.In this context,a generic VHTS mission utilizing Q/V-band feeder links and Ka-band user links is described.However,the rain attenuation on the feeder links becomes a limiting issue because of the higher frequencies.Toward this,an exploitation of multiple gateways (GWs) as a transmit diversity measure for overcoming severe propagation effects are being considered.Ground Application System (GAS) design of VHTS is illustrated including N+P GWs (N active and P redundant GWs) diversity,frequency plan,link budget and system capacity.展开更多
The re-entrant double-staggered ladder slow-wave structure is employed in a high-power V-band coupled-cavity traveling-wave tube. This structure has a wide bandwidth, a moderate interaction impedance, and excellent th...The re-entrant double-staggered ladder slow-wave structure is employed in a high-power V-band coupled-cavity traveling-wave tube. This structure has a wide bandwidth, a moderate interaction impedance, and excellent thermal dissipation properties, as well as easy fabrication. A well-matched waveguide coupler is proposed for the structure. Combining the design of attenuators, a full-scale three-dimensional circuit model for the V-band coupled-cavity traveling- wave tube is constructed. The electromagnetic characteristics and the beam wave interaction of this structure are investigated. The beam current is set to be 100 mA, and the cathode voltage is tuned from 16.8 kV to 15.8 kV. The calculation results show that this tube can produce a saturated average output power over 100 W with an instantaneous bandwidth greater than 1.25 GHz in the frequency ranging from 58 GHz to 62 GHz. The corresponding gain and electronic efficiency can reach over 32 dB and 6.5%, respectively.展开更多
A high-linearity down mixer with outstanding robust temperature tolerance for V-band applications is proposed in this paper.The mixer’s temperature robustness has been greatly enhanced by employing a negative tempera...A high-linearity down mixer with outstanding robust temperature tolerance for V-band applications is proposed in this paper.The mixer’s temperature robustness has been greatly enhanced by employing a negative temperature-compensation circuit(NTC)and a positive temperature-compensation circuit(PTC)in the transconductance(g_(m))stage and intermediate frequency(IF)output buffer,respectively.Benefiting from the active balun with enhanced g_(m)and emitter negative feedback technique,the linearity of the mixer has been significantly improved.For verification,a double-balanced V-band mixer is designed and implemented in a 130 nm SiGe BiCMOS process.Measured over the local oscillator(LO)bandwidth from 57 GHz to 63 GHz,the mixer demonstrates a peak conversion gain(CG)of−0.5 dB,a minimal noise figure(NF)of 11.5 dB,and an input 1 dB compression point(IP_(1 dB))of 4.8 dBm under an LO power of−3 dBm.Furthermore,the measurements of CG,NF,and IP_(1 dB)exhibit commendable consistency within the temperature range of−55℃to 85℃,with fluctuations of less than 0.8 dB,1 dB,and 1.2 dBm,respectively.From 57 GHz to 63 GHz,the measured LO-to-radio frequency(RF)isolation is better than 46 dB,the measured return loss at the RF port is>29 dB,and at the LO port it exceeds 12 dB.With a 2.5 V supply voltage,the mixer power consumption is 15.75 mW,18.5 mW,and 21 mW at temperatures of−55℃,25℃,and 85℃,respectively.Moreover,the mixer chip occupies a total silicon area of 0.56 mm2 including all testing pads.展开更多
为了减缓飞行器在临近空间高速飞行时产生的等离子体鞘套"黑障"对其通信影响,根据ITU分配的临近空间3区业务频段,设计了一种在Ka/V双频段工作的口径耦合微带天线。该天线在中间缝隙开一圆孔,通过改变圆孔大小实现双频工作,并...为了减缓飞行器在临近空间高速飞行时产生的等离子体鞘套"黑障"对其通信影响,根据ITU分配的临近空间3区业务频段,设计了一种在Ka/V双频段工作的口径耦合微带天线。该天线在中间缝隙开一圆孔,通过改变圆孔大小实现双频工作,并组成1×4的天线阵列,实现了在Ka和V两个频段的通信。设计结果表明:在Ka频段的-10 d B带宽达到11.33%,V频段带宽达到2.52%,满足其在临近空间3区业务的通信频段。该天线易于实现,结构简单,可为临近空间通信飞行器天线设计提供参考。展开更多
文摘Over the next decade,Very High-Throughput Satellite (VHTS) will bring enough capacity to serve high speed internet and in-flight connectivity markets at scale,offering fiber-like services both in terms of price and speed.In this context,a generic VHTS mission utilizing Q/V-band feeder links and Ka-band user links is described.However,the rain attenuation on the feeder links becomes a limiting issue because of the higher frequencies.Toward this,an exploitation of multiple gateways (GWs) as a transmit diversity measure for overcoming severe propagation effects are being considered.Ground Application System (GAS) design of VHTS is illustrated including N+P GWs (N active and P redundant GWs) diversity,frequency plan,link budget and system capacity.
基金Project supported by the National Science Fund for Distinguished Young Scholars of China (Grant No. 61125103)the Vacuum Electronics National Lab Foundation, China (Grant No. 9140C050101110C0501)the Fundamental Research Funds for the Central Universities, China (Grant Nos. ZYGX2009Z003 and ZYGX2010J054)
文摘The re-entrant double-staggered ladder slow-wave structure is employed in a high-power V-band coupled-cavity traveling-wave tube. This structure has a wide bandwidth, a moderate interaction impedance, and excellent thermal dissipation properties, as well as easy fabrication. A well-matched waveguide coupler is proposed for the structure. Combining the design of attenuators, a full-scale three-dimensional circuit model for the V-band coupled-cavity traveling- wave tube is constructed. The electromagnetic characteristics and the beam wave interaction of this structure are investigated. The beam current is set to be 100 mA, and the cathode voltage is tuned from 16.8 kV to 15.8 kV. The calculation results show that this tube can produce a saturated average output power over 100 W with an instantaneous bandwidth greater than 1.25 GHz in the frequency ranging from 58 GHz to 62 GHz. The corresponding gain and electronic efficiency can reach over 32 dB and 6.5%, respectively.
基金supported by the National Key Research and Development Program of China(No.2023YFB3811503)the Zhejiang Provincial Natural Science Foundation of China(No.LQ23F040009)the State Key Laboratory of Millimeter Waves,Southeast University(No.K202316)。
文摘A high-linearity down mixer with outstanding robust temperature tolerance for V-band applications is proposed in this paper.The mixer’s temperature robustness has been greatly enhanced by employing a negative temperature-compensation circuit(NTC)and a positive temperature-compensation circuit(PTC)in the transconductance(g_(m))stage and intermediate frequency(IF)output buffer,respectively.Benefiting from the active balun with enhanced g_(m)and emitter negative feedback technique,the linearity of the mixer has been significantly improved.For verification,a double-balanced V-band mixer is designed and implemented in a 130 nm SiGe BiCMOS process.Measured over the local oscillator(LO)bandwidth from 57 GHz to 63 GHz,the mixer demonstrates a peak conversion gain(CG)of−0.5 dB,a minimal noise figure(NF)of 11.5 dB,and an input 1 dB compression point(IP_(1 dB))of 4.8 dBm under an LO power of−3 dBm.Furthermore,the measurements of CG,NF,and IP_(1 dB)exhibit commendable consistency within the temperature range of−55℃to 85℃,with fluctuations of less than 0.8 dB,1 dB,and 1.2 dBm,respectively.From 57 GHz to 63 GHz,the measured LO-to-radio frequency(RF)isolation is better than 46 dB,the measured return loss at the RF port is>29 dB,and at the LO port it exceeds 12 dB.With a 2.5 V supply voltage,the mixer power consumption is 15.75 mW,18.5 mW,and 21 mW at temperatures of−55℃,25℃,and 85℃,respectively.Moreover,the mixer chip occupies a total silicon area of 0.56 mm2 including all testing pads.
文摘为了减缓飞行器在临近空间高速飞行时产生的等离子体鞘套"黑障"对其通信影响,根据ITU分配的临近空间3区业务频段,设计了一种在Ka/V双频段工作的口径耦合微带天线。该天线在中间缝隙开一圆孔,通过改变圆孔大小实现双频工作,并组成1×4的天线阵列,实现了在Ka和V两个频段的通信。设计结果表明:在Ka频段的-10 d B带宽达到11.33%,V频段带宽达到2.52%,满足其在临近空间3区业务的通信频段。该天线易于实现,结构简单,可为临近空间通信飞行器天线设计提供参考。
