High Te superconductor （HTS） technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and ...High Te superconductor （HTS） technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and experimental approaches have proceeded for the concept verification. This paper presents the theory about this high Q resonant circuit. The operation principle of the circuit is described. A practical prototype for HTS high voltage generation is also demonstrated. The experiment result shows that very high voltages can be achieved by the developed method using HTS technology.展开更多
In pursuit of high-precision beam position measurements at micrometers or submicrometers for the Shanghai soft X-ray free-electron laser(SXFEL) facility which is under construction in the vicinity of the Shanghai Sync...In pursuit of high-precision beam position measurements at micrometers or submicrometers for the Shanghai soft X-ray free-electron laser(SXFEL) facility which is under construction in the vicinity of the Shanghai Synchrotron Radiation Facility,a high Q cavity beam position monitor(CBPM) with a resonant frequency of4.7 GHz is developed by the Shanghai Institute of Applied Physics,and the relevant BPM electronics with a dedicated RF front end,and a digital BPM,are completed.The cavity design,cold test,system architecture,and first beam test are performed at the Shanghai deep ultraviolet free-electron laser(Zhao et al.in Nucl Instrum Meth A 528(1-2):591-594,2004.doi:10.1016/j.nima.2004.04.108) facility.Results of the beam experiment show that the performance of the CBPM is consistent with basic expectations,and the beam position resolution can fulfill the requirements for the SXFEL project if the beam conditions are optimized.展开更多
A design of a linear and fully-balanced operational transconductanee amplifier （OTA） with improved high DC gain and wide bandwidth is presented. Derivative from a single common-source field effect transistor （FET）...A design of a linear and fully-balanced operational transconductanee amplifier （OTA） with improved high DC gain and wide bandwidth is presented. Derivative from a single common-source field effect transistor （FET） cas- cade and its DC I-V characteristics,the third-order coefficient g3 hasbeen well compensated with a parallel FET operated in the triode region, which has even-odd symmetries between the boundary of the saturation and triode region. Therefore,for high linearity,a simple solution is obtained to increase input signal amplitude in saturation for the application of OTA continuous-time filters. A negative resistance load （NRL） technique is used for the compensation of parasitic output resistance and an achievement of a high DC-gain of the OTA circuits without extra internal nodes. Additionally, derivations from the ideal -90° phase of the gm-C integrator mainly due to a finite DC gain and parasitic poles will be avoided in the frequency range of interest. HSPICE simulation shows that the total harmonic distortion at 1Vp-p is less than 1% from a single 3.3V supply. As an application of the VHF CMOS OTA,a second-order OTA-C bandpass filter is fabricated using a 0. 18μm CMOS process with two kinds of gate-oxide layers, which has achieved a center frequency of 20MHz,a 3dB-bandwidth of 180kHz,and a quality factor of 110.展开更多
A terahertz asymmetrically coupled resonator （ACR） consisting of two different split ring resonators （SRRs） was designed. Using finite difference time domain （FDTD）, the transmission of ACR and its refractive-in...A terahertz asymmetrically coupled resonator （ACR） consisting of two different split ring resonators （SRRs） was designed. Using finite difference time domain （FDTD）, the transmission of ACR and its refractive-index- based sensing performaance were simulated and analyzed. Results show that the ACR possesses a sharp coupled transparent peak or high quality factor （Q）, its intensity and bandwidth can be easily adjusted by spacing the two SRRs. Furthermore, the resonator exhibits high sensitivity of 75 GHz/RIU and figure of merit （FOM） of 4.4, much higher than the individual SRR sensors. The ACR were fabricated by using laser-induced and chemical non-electrolytic plating with copper on polyimide substrate, the transmission of which measured by terahertz time-domain spectroscopy system is in good agreement with simulations.展开更多
High Q reflection filter using a gradient-index(GI) membrane with a grating surface is proposed. The thickness of GI membrane is very small comparing with the traditional multilayer reflection filter or the GI reflect...High Q reflection filter using a gradient-index(GI) membrane with a grating surface is proposed. The thickness of GI membrane is very small comparing with the traditional multilayer reflection filter or the GI reflection filter, and the GI membrane can also break the restriction of the resonant excitation condition of the conventional guided-mode resonance(GMR) filter. High Q filtering features can be maintained even on the high-index substrate. The grating thickness of the GI membrane filter can be used to select the resonance wavelength with different quality factors(QFs), the reflection peak is blue-shifted, and the QF is decreased from 554.4 to 207.8 as the grating thickness is increased from 50 nm to 150 nm. The gradient coefficient of the GI membrane filter can be used to tailor the number of the reflection channels. The resonant excitations of high order waveguide modes confined in the GI membrane are responsible for the high Q filtering properties with multiple channels.展开更多
文摘High Te superconductor （HTS） technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and experimental approaches have proceeded for the concept verification. This paper presents the theory about this high Q resonant circuit. The operation principle of the circuit is described. A practical prototype for HTS high voltage generation is also demonstrated. The experiment result shows that very high voltages can be achieved by the developed method using HTS technology.
基金supported by the National Natural Science Foundation of China(Nos.11575282 and 11305253)
文摘In pursuit of high-precision beam position measurements at micrometers or submicrometers for the Shanghai soft X-ray free-electron laser(SXFEL) facility which is under construction in the vicinity of the Shanghai Synchrotron Radiation Facility,a high Q cavity beam position monitor(CBPM) with a resonant frequency of4.7 GHz is developed by the Shanghai Institute of Applied Physics,and the relevant BPM electronics with a dedicated RF front end,and a digital BPM,are completed.The cavity design,cold test,system architecture,and first beam test are performed at the Shanghai deep ultraviolet free-electron laser(Zhao et al.in Nucl Instrum Meth A 528(1-2):591-594,2004.doi:10.1016/j.nima.2004.04.108) facility.Results of the beam experiment show that the performance of the CBPM is consistent with basic expectations,and the beam position resolution can fulfill the requirements for the SXFEL project if the beam conditions are optimized.
文摘A design of a linear and fully-balanced operational transconductanee amplifier （OTA） with improved high DC gain and wide bandwidth is presented. Derivative from a single common-source field effect transistor （FET） cas- cade and its DC I-V characteristics,the third-order coefficient g3 hasbeen well compensated with a parallel FET operated in the triode region, which has even-odd symmetries between the boundary of the saturation and triode region. Therefore,for high linearity,a simple solution is obtained to increase input signal amplitude in saturation for the application of OTA continuous-time filters. A negative resistance load （NRL） technique is used for the compensation of parasitic output resistance and an achievement of a high DC-gain of the OTA circuits without extra internal nodes. Additionally, derivations from the ideal -90° phase of the gm-C integrator mainly due to a finite DC gain and parasitic poles will be avoided in the frequency range of interest. HSPICE simulation shows that the total harmonic distortion at 1Vp-p is less than 1% from a single 3.3V supply. As an application of the VHF CMOS OTA,a second-order OTA-C bandpass filter is fabricated using a 0. 18μm CMOS process with two kinds of gate-oxide layers, which has achieved a center frequency of 20MHz,a 3dB-bandwidth of 180kHz,and a quality factor of 110.
文摘A terahertz asymmetrically coupled resonator （ACR） consisting of two different split ring resonators （SRRs） was designed. Using finite difference time domain （FDTD）, the transmission of ACR and its refractive-index- based sensing performaance were simulated and analyzed. Results show that the ACR possesses a sharp coupled transparent peak or high quality factor （Q）, its intensity and bandwidth can be easily adjusted by spacing the two SRRs. Furthermore, the resonator exhibits high sensitivity of 75 GHz/RIU and figure of merit （FOM） of 4.4, much higher than the individual SRR sensors. The ACR were fabricated by using laser-induced and chemical non-electrolytic plating with copper on polyimide substrate, the transmission of which measured by terahertz time-domain spectroscopy system is in good agreement with simulations.
基金supported by the National Natural Science Foundation of China(No.11404143)the Fundamental Research Funds for the Central Universities(No.JUSRP115A15)the Jiangsu Provincial Research Center of Light Industrial Optoelectronic Engineering and Technology(No.BM2014402)
文摘High Q reflection filter using a gradient-index(GI) membrane with a grating surface is proposed. The thickness of GI membrane is very small comparing with the traditional multilayer reflection filter or the GI reflection filter, and the GI membrane can also break the restriction of the resonant excitation condition of the conventional guided-mode resonance(GMR) filter. High Q filtering features can be maintained even on the high-index substrate. The grating thickness of the GI membrane filter can be used to select the resonance wavelength with different quality factors(QFs), the reflection peak is blue-shifted, and the QF is decreased from 554.4 to 207.8 as the grating thickness is increased from 50 nm to 150 nm. The gradient coefficient of the GI membrane filter can be used to tailor the number of the reflection channels. The resonant excitations of high order waveguide modes confined in the GI membrane are responsible for the high Q filtering properties with multiple channels.
