The China initiative Accelerator Driven System,CiADS,physics design adopts 162.5 MHz,325 MHz,and 650 MHz cavities,which are driven by the corresponding radio frequency(RF)power system,requiring frequency translation f...The China initiative Accelerator Driven System,CiADS,physics design adopts 162.5 MHz,325 MHz,and 650 MHz cavities,which are driven by the corresponding radio frequency(RF)power system,requiring frequency translation front-end for the RF station.For that application,a general-purpose design front-end prototype has been developed to evaluate the multi-frequency point supported design feasibility.The difficult parts to achieve the requirements of the general-purpose design are reasonable device selection and balanced design.With a carefully selected low-noise wide-band RF mixer and amplifier to balance the performance of multi-frequency supported down-conversion,specially designed LO distribution net to increase isolation between adjacent channels,and external band-pass filter to realize expected up-conversion frequencies,high maintenance and modular front-end generalpurpose design has been implemented.Results of standard parameters show an R2 value of at least 99.991%in the range of-60-10 dBm for linearity,up to 18 dBm for P1dB,and up to 89 dBc for cross talk between adjacent channels.The phase noise spectrum is lower than 80 dBc in the range of 0-1 MHz;cumulative phase noise is 0.006°;and amplitude and phase stability are 0.022%and 0.034°,respectively.展开更多
RF circuit board has a significant impact on performance of the Digital Beam Position Monitor (DBPM) in storage ring of a synchrotron radiation facility.In this paper,a front-end RF board is designed for DBPM,and sche...RF circuit board has a significant impact on performance of the Digital Beam Position Monitor (DBPM) in storage ring of a synchrotron radiation facility.In this paper,a front-end RF board is designed for DBPM,and schematics of the RF board and the test results are given.In view of the inevitable inconsistency in the multi-channel circuit,a calibration circuit is designed to reduce such an influence.The test results show that the calibration method is useful for beam current dependence which is sensitive to channels inconsistency.展开更多
Nowadays, we are witnessing an era marked by the autonomy of wireless devices and sensor networks without the aid of batteries. RF energy harvesting therefore becomes a promising alternative for battery dependence. Th...Nowadays, we are witnessing an era marked by the autonomy of wireless devices and sensor networks without the aid of batteries. RF energy harvesting therefore becomes a promising alternative for battery dependence. This work presents the design of an RF energy harvesting system consisting mainly of a rectenna (antenna and rectification circuit) and an adaptation circuit. First of all, we designed two dipole type antennas. One operates in the GSM 900 MHz band and the other in the GSM 1800 MHz band. The performances of the proposed antennas are provided by the ANSYS HFSS software. Secondly, we proposed two rectification circuits in order to obtain conversion efficiencies at 0 dBm of 64% for the system operating at the frequency of 900 MHz and 37% for the system at the frequency of 1800 MHz RF-DC. The rectifiers used are based on Schottky diodes. For maximum transfer of power between the antenna and the rectification circuit, L-type matching circuits have been proposed. This rectifier offers DC voltage values of 806 mV for the circuit at the frequency of 900 MHz and 616 mV for the circuit at the frequency of 1800 MHz. The adaptation circuits are obtained by carrying out simulations on the ADS (Advanced Design System) software.展开更多
针对现有低功耗蓝牙(BLE)欺骗攻击检测技术准确率低的问题,提出了一种基于异常指纹的BLE欺骗攻击检测技术,将攻击者的射频指纹作为异常数据,把欺骗攻击检测建模为异常检测问题;设计了一种基于深度支持向量描述(Deep Support Vector Data...针对现有低功耗蓝牙(BLE)欺骗攻击检测技术准确率低的问题,提出了一种基于异常指纹的BLE欺骗攻击检测技术,将攻击者的射频指纹作为异常数据,把欺骗攻击检测建模为异常检测问题;设计了一种基于深度支持向量描述(Deep Support Vector Data Description,DeepSVDD)的异常指纹检测模型——RFFAD_DeepSVDD,并使用残差单元构建网络模型,有效缓解了机器学习异常检测算法非线性特征提取不足的问题。采用预训练自编码器获取最优初始化参数,极大增强了模型边界决策能力。在异常检测实验中,该模型准确率达到95.47%,相比基于机器学习的异常检测模型平均提升8.92%;在欺骗攻击检测实验中,该方法相比现有欺骗攻击检测技术在攻击节点运动与静止状态下均表现出更好的性能,能够准确检测并识别出中间人攻击、冒充攻击、重连接欺骗攻击3种欺骗攻击。展开更多
绝缘油是电抗器内部重要的绝缘介质,击穿电压是评估其绝缘特性的关键指标,与绝缘油的品质状态密切相关。本文共选取155组电抗器绝缘油进行实验,分别进行击穿电压的测定和多频超声信号在油样中传播衰减后信号的采集,分析多频超声声学参...绝缘油是电抗器内部重要的绝缘介质,击穿电压是评估其绝缘特性的关键指标,与绝缘油的品质状态密切相关。本文共选取155组电抗器绝缘油进行实验,分别进行击穿电压的测定和多频超声信号在油样中传播衰减后信号的采集,分析多频超声声学参数和击穿电压之间的幅频响应、相频响应之间的关系,并基于多频超声检测技术提出结合灰狼优化算法(grey wolf optimizer,GWO)优化随机森林算法(random forest algorithm,RF)的击穿电压预测方法。结果表明:GWO-RF绝缘油击穿电压预测模型的预测值与实际值的平均相对误差为4.04%,预测准确率达到95.96%,相较于优化前的RF绝缘油击穿电压预测模型准确率提升了20.25%。结合多频超声检测技术和GWO-RF建立的并联电抗器绝缘油击穿电压预测模型,对击穿电压的预测具有可行性。展开更多
An analog front-end of HF passive RFID transponders compatible with ISO/IEC 18000-3 is presented.Design considerations, especially the power transmission in the RFID transponder, are analyzed. Based on these considera...An analog front-end of HF passive RFID transponders compatible with ISO/IEC 18000-3 is presented.Design considerations, especially the power transmission in the RFID transponder, are analyzed. Based on these considerations,an analog front-end is presented with novel architecture, high power conversion efficiency, low voltage, low power consumption, and high performance in an environment of noise and power fluctuation. The circuit is implemented in a Chartered 0.35μm standard CMOS process. The experimental results show that the chip can satisfy the design target well.展开更多
This paper presents a fully integrated RF front-end with an automatic gain control（AGC） scheme and a digitally controlled radio frequency varied gain amplifier（RFVGA） for a U/V band China Mobile Multimedia Broadca...This paper presents a fully integrated RF front-end with an automatic gain control（AGC） scheme and a digitally controlled radio frequency varied gain amplifier（RFVGA） for a U/V band China Mobile Multimedia Broadcasting（CMMB） direct conversion receiver.The RFVGA provides a gain range of 50 dB with a 1.6 dB step. The adopted AGC strategy could improve immunity to adjacent channel signal,which is of importance for CMMB application.The front-end,composed of a low noise amplifier（LNA）,an RFVGA,a mixer and AGC,achieves an input referred 3rd order intercept point（IIP3） of 4.9 dBm with the LNA in low gain mode and the RFVGA in medium gain mode,and a less than 4 dB double side band noise figure with both the LNA and the RFVGA in high gain mode.The proposed RF front-end is fabricated in a 0.35μm SiGe BiCMOS technology and consumes 25.6 mA from a 3.0 V power supply.展开更多
A CMOS RF（radio frequency） front-end for digital radio broadcasting applications is presented that contains a wideband LNA,I/Q-mixers and VGAs,supporting other various wireless communication standards in the ultrawi...A CMOS RF（radio frequency） front-end for digital radio broadcasting applications is presented that contains a wideband LNA,I/Q-mixers and VGAs,supporting other various wireless communication standards in the ultrawide frequency band from 200 kHz to 2 GHz as well.Improvement of the NF（noise figure） and IP3（third-order intermodulation distortion） is attained without significant degradation of other performances like voltage gain and power consumption.The NF is minimized by noise-canceling technology,and the IP3 is improved by using differential multiple gate transistors（DMGTR）.The dB-in-linear VGA（variable gain amplifier） exploits a single PMOS to achieve exponential gain control.The circuit is fabricated in 0.18-μm CMOS technology.The S11 of the RF front-end is lower than -11.4 dB over the whole band of 200 kHz-2 GHz.The variable gain range is 12-42 dB at 0.25 GHz and 4-36 dB at 2 GHz.The DSB NF at maximum gain is 3.1-6.1 dB.The IIP3 at middle gain is -4.7 to 0.2 dBm.It consumes a DC power of only 36 mW at 1.8 V supply.展开更多
文摘The China initiative Accelerator Driven System,CiADS,physics design adopts 162.5 MHz,325 MHz,and 650 MHz cavities,which are driven by the corresponding radio frequency(RF)power system,requiring frequency translation front-end for the RF station.For that application,a general-purpose design front-end prototype has been developed to evaluate the multi-frequency point supported design feasibility.The difficult parts to achieve the requirements of the general-purpose design are reasonable device selection and balanced design.With a carefully selected low-noise wide-band RF mixer and amplifier to balance the performance of multi-frequency supported down-conversion,specially designed LO distribution net to increase isolation between adjacent channels,and external band-pass filter to realize expected up-conversion frequencies,high maintenance and modular front-end generalpurpose design has been implemented.Results of standard parameters show an R2 value of at least 99.991%in the range of-60-10 dBm for linearity,up to 18 dBm for P1dB,and up to 89 dBc for cross talk between adjacent channels.The phase noise spectrum is lower than 80 dBc in the range of 0-1 MHz;cumulative phase noise is 0.006°;and amplitude and phase stability are 0.022%and 0.034°,respectively.
基金Supported by 100 Talents Program of The Chinese Academy of Sciences
文摘RF circuit board has a significant impact on performance of the Digital Beam Position Monitor (DBPM) in storage ring of a synchrotron radiation facility.In this paper,a front-end RF board is designed for DBPM,and schematics of the RF board and the test results are given.In view of the inevitable inconsistency in the multi-channel circuit,a calibration circuit is designed to reduce such an influence.The test results show that the calibration method is useful for beam current dependence which is sensitive to channels inconsistency.
文摘Nowadays, we are witnessing an era marked by the autonomy of wireless devices and sensor networks without the aid of batteries. RF energy harvesting therefore becomes a promising alternative for battery dependence. This work presents the design of an RF energy harvesting system consisting mainly of a rectenna (antenna and rectification circuit) and an adaptation circuit. First of all, we designed two dipole type antennas. One operates in the GSM 900 MHz band and the other in the GSM 1800 MHz band. The performances of the proposed antennas are provided by the ANSYS HFSS software. Secondly, we proposed two rectification circuits in order to obtain conversion efficiencies at 0 dBm of 64% for the system operating at the frequency of 900 MHz and 37% for the system at the frequency of 1800 MHz RF-DC. The rectifiers used are based on Schottky diodes. For maximum transfer of power between the antenna and the rectification circuit, L-type matching circuits have been proposed. This rectifier offers DC voltage values of 806 mV for the circuit at the frequency of 900 MHz and 616 mV for the circuit at the frequency of 1800 MHz. The adaptation circuits are obtained by carrying out simulations on the ADS (Advanced Design System) software.
文摘针对现有低功耗蓝牙(BLE)欺骗攻击检测技术准确率低的问题,提出了一种基于异常指纹的BLE欺骗攻击检测技术,将攻击者的射频指纹作为异常数据,把欺骗攻击检测建模为异常检测问题;设计了一种基于深度支持向量描述(Deep Support Vector Data Description,DeepSVDD)的异常指纹检测模型——RFFAD_DeepSVDD,并使用残差单元构建网络模型,有效缓解了机器学习异常检测算法非线性特征提取不足的问题。采用预训练自编码器获取最优初始化参数,极大增强了模型边界决策能力。在异常检测实验中,该模型准确率达到95.47%,相比基于机器学习的异常检测模型平均提升8.92%;在欺骗攻击检测实验中,该方法相比现有欺骗攻击检测技术在攻击节点运动与静止状态下均表现出更好的性能,能够准确检测并识别出中间人攻击、冒充攻击、重连接欺骗攻击3种欺骗攻击。
文摘绝缘油是电抗器内部重要的绝缘介质,击穿电压是评估其绝缘特性的关键指标,与绝缘油的品质状态密切相关。本文共选取155组电抗器绝缘油进行实验,分别进行击穿电压的测定和多频超声信号在油样中传播衰减后信号的采集,分析多频超声声学参数和击穿电压之间的幅频响应、相频响应之间的关系,并基于多频超声检测技术提出结合灰狼优化算法(grey wolf optimizer,GWO)优化随机森林算法(random forest algorithm,RF)的击穿电压预测方法。结果表明:GWO-RF绝缘油击穿电压预测模型的预测值与实际值的平均相对误差为4.04%,预测准确率达到95.96%,相较于优化前的RF绝缘油击穿电压预测模型准确率提升了20.25%。结合多频超声检测技术和GWO-RF建立的并联电抗器绝缘油击穿电压预测模型,对击穿电压的预测具有可行性。
文摘An analog front-end of HF passive RFID transponders compatible with ISO/IEC 18000-3 is presented.Design considerations, especially the power transmission in the RFID transponder, are analyzed. Based on these considerations,an analog front-end is presented with novel architecture, high power conversion efficiency, low voltage, low power consumption, and high performance in an environment of noise and power fluctuation. The circuit is implemented in a Chartered 0.35μm standard CMOS process. The experimental results show that the chip can satisfy the design target well.
文摘This paper presents a fully integrated RF front-end with an automatic gain control（AGC） scheme and a digitally controlled radio frequency varied gain amplifier（RFVGA） for a U/V band China Mobile Multimedia Broadcasting（CMMB） direct conversion receiver.The RFVGA provides a gain range of 50 dB with a 1.6 dB step. The adopted AGC strategy could improve immunity to adjacent channel signal,which is of importance for CMMB application.The front-end,composed of a low noise amplifier（LNA）,an RFVGA,a mixer and AGC,achieves an input referred 3rd order intercept point（IIP3） of 4.9 dBm with the LNA in low gain mode and the RFVGA in medium gain mode,and a less than 4 dB double side band noise figure with both the LNA and the RFVGA in high gain mode.The proposed RF front-end is fabricated in a 0.35μm SiGe BiCMOS technology and consumes 25.6 mA from a 3.0 V power supply.
文摘A CMOS RF（radio frequency） front-end for digital radio broadcasting applications is presented that contains a wideband LNA,I/Q-mixers and VGAs,supporting other various wireless communication standards in the ultrawide frequency band from 200 kHz to 2 GHz as well.Improvement of the NF（noise figure） and IP3（third-order intermodulation distortion） is attained without significant degradation of other performances like voltage gain and power consumption.The NF is minimized by noise-canceling technology,and the IP3 is improved by using differential multiple gate transistors（DMGTR）.The dB-in-linear VGA（variable gain amplifier） exploits a single PMOS to achieve exponential gain control.The circuit is fabricated in 0.18-μm CMOS technology.The S11 of the RF front-end is lower than -11.4 dB over the whole band of 200 kHz-2 GHz.The variable gain range is 12-42 dB at 0.25 GHz and 4-36 dB at 2 GHz.The DSB NF at maximum gain is 3.1-6.1 dB.The IIP3 at middle gain is -4.7 to 0.2 dBm.It consumes a DC power of only 36 mW at 1.8 V supply.
