针对超宽带系统谐杂波抑制难、动态范围、灵敏度易恶化,提出了在变频前端采用高集成、超宽带开关滤波组件分段滤波,以提高整个系统的灵敏度,动态范围、选频、抗干扰等关键指标。设计了开关加滤波器组的方案,对8~18GHz信号分为10段分别...针对超宽带系统谐杂波抑制难、动态范围、灵敏度易恶化,提出了在变频前端采用高集成、超宽带开关滤波组件分段滤波,以提高整个系统的灵敏度,动态范围、选频、抗干扰等关键指标。设计了开关加滤波器组的方案,对8~18GHz信号分为10段分别滤波的方式,并对滤波器和开关进行了设计仿真,实现了小型化、高可靠、电路控制速度快的高集成、超宽带开关滤波组件。实验结果表明,该电路噪声系数达14 d B,增益12 d B,相位一致性≤±10°,通道隔离度≥45d B,试验结果达到预期目标。展开更多
The design and fabrication of a RF MEMS switch is reported for the first time in China.The switching element consists of a thin metallic membrane,which has the metal-isolator-metal contact and a capacitive shunt switc...The design and fabrication of a RF MEMS switch is reported for the first time in China.The switching element consists of a thin metallic membrane,which has the metal-isolator-metal contact and a capacitive shunt switch as single-pole single-throw.When an electrostatic potential is applied to the membrane and the bottom electrode,the attractive electrostatic force pulls the metal membrane down onto the bottom dielectric.The switch characteristics,such as insertion loss and isolation,depend on the off and on-capacitance.The test results are as follows:the pulldown voltage is about 20V;the insertion loss is less than 0 69dB from DC to 20GHz in the up-state;the isolation is more than 13dB from 14 to 18GHz and 16dB from 18 to 20GHz in the down-state.展开更多
The experiment results of ultrawide band electromagnetic radiation with DC biased GaAs photoconductive semiconductor switch combining double ridge horn antenna triggered by high repeat frequency femto-second laser pul...The experiment results of ultrawide band electromagnetic radiation with DC biased GaAs photoconductive semiconductor switch combining double ridge horn antenna triggered by high repeat frequency femto-second laser pulse are reported.The GaAs switches are insulated by solid multi-layer transparent dielectrics and the distance of two electrodes is 3mm.The electrode material of the switch is ohmic contact through alloy technics with definite proportion of Au/Ge/Ni.This switch and double ridge horn antenna are integrated and the receive antenna is connected with the test instrument.From receiving antenna,ultra fast electrical pulse of 200ps rise time and 500ps pulse width is obtained,the repetition rate of the pulse is about 82MHz and the frequency spectrum is in the range of 4.7MHz～14GHz.The radiation characteristic of the ultrafast electrical pulse is analyzed.展开更多
A novel charge exchanging compensation （CEC） technique is proposed for a wideband sample-and-hold （S/H） circuit applied in an IF sampling ADC. The CEC technique compensates the sampling bandwidth by eliminating th...A novel charge exchanging compensation （CEC） technique is proposed for a wideband sample-and-hold （S/H） circuit applied in an IF sampling ADC. The CEC technique compensates the sampling bandwidth by eliminating the impact from finite on-resistance of the sampling switch, and avoids increasing clock feedthrough and charge injection. Meanwhile, a low power two stage OTA with a class AB output stage is designed to provide the S/H a 3Vp-p input range under 1.8V power. The S/H achieves a 94dB spurious-free dynamic range for a 200MHz input signal at a 100Ms/s sample rate and consumes only 26mW with a 5.5pF load.展开更多
A semiconductor optical amplifier gate based on tensile strained quasi bulk InGaAs is developed.At injection current of 80mA,a 3dB optical bandwidth of more than 85nm is achieved due to dominant band filling effect...A semiconductor optical amplifier gate based on tensile strained quasi bulk InGaAs is developed.At injection current of 80mA,a 3dB optical bandwidth of more than 85nm is achieved due to dominant band filling effect.Moreover,the most important is that very low polarization dependence of gain (<0 7dB),fiber to fiber lossless operation current (70～90mA) and a high extinction ratio (>50dB) are simultaneously obtained over this wide 3dB optical bandwidth (1520～1609nm) which nearly covers the spectral region of the whole C band (1525～1565nm) and the whole L band (1570～1610nm).The gating time is also improved by decreasing carrier lifetime.The wide band polarization insensitive SOA gate is promising for use in future dense wavelength division multiplexing (DWDM) communication systems.展开更多
文摘针对超宽带系统谐杂波抑制难、动态范围、灵敏度易恶化,提出了在变频前端采用高集成、超宽带开关滤波组件分段滤波,以提高整个系统的灵敏度,动态范围、选频、抗干扰等关键指标。设计了开关加滤波器组的方案,对8~18GHz信号分为10段分别滤波的方式,并对滤波器和开关进行了设计仿真,实现了小型化、高可靠、电路控制速度快的高集成、超宽带开关滤波组件。实验结果表明,该电路噪声系数达14 d B,增益12 d B,相位一致性≤±10°,通道隔离度≥45d B,试验结果达到预期目标。
文摘The design and fabrication of a RF MEMS switch is reported for the first time in China.The switching element consists of a thin metallic membrane,which has the metal-isolator-metal contact and a capacitive shunt switch as single-pole single-throw.When an electrostatic potential is applied to the membrane and the bottom electrode,the attractive electrostatic force pulls the metal membrane down onto the bottom dielectric.The switch characteristics,such as insertion loss and isolation,depend on the off and on-capacitance.The test results are as follows:the pulldown voltage is about 20V;the insertion loss is less than 0 69dB from DC to 20GHz in the up-state;the isolation is more than 13dB from 14 to 18GHz and 16dB from 18 to 20GHz in the down-state.
文摘The experiment results of ultrawide band electromagnetic radiation with DC biased GaAs photoconductive semiconductor switch combining double ridge horn antenna triggered by high repeat frequency femto-second laser pulse are reported.The GaAs switches are insulated by solid multi-layer transparent dielectrics and the distance of two electrodes is 3mm.The electrode material of the switch is ohmic contact through alloy technics with definite proportion of Au/Ge/Ni.This switch and double ridge horn antenna are integrated and the receive antenna is connected with the test instrument.From receiving antenna,ultra fast electrical pulse of 200ps rise time and 500ps pulse width is obtained,the repetition rate of the pulse is about 82MHz and the frequency spectrum is in the range of 4.7MHz～14GHz.The radiation characteristic of the ultrafast electrical pulse is analyzed.
文摘A novel charge exchanging compensation （CEC） technique is proposed for a wideband sample-and-hold （S/H） circuit applied in an IF sampling ADC. The CEC technique compensates the sampling bandwidth by eliminating the impact from finite on-resistance of the sampling switch, and avoids increasing clock feedthrough and charge injection. Meanwhile, a low power two stage OTA with a class AB output stage is designed to provide the S/H a 3Vp-p input range under 1.8V power. The S/H achieves a 94dB spurious-free dynamic range for a 200MHz input signal at a 100Ms/s sample rate and consumes only 26mW with a 5.5pF load.
文摘A semiconductor optical amplifier gate based on tensile strained quasi bulk InGaAs is developed.At injection current of 80mA,a 3dB optical bandwidth of more than 85nm is achieved due to dominant band filling effect.Moreover,the most important is that very low polarization dependence of gain (<0 7dB),fiber to fiber lossless operation current (70～90mA) and a high extinction ratio (>50dB) are simultaneously obtained over this wide 3dB optical bandwidth (1520～1609nm) which nearly covers the spectral region of the whole C band (1525～1565nm) and the whole L band (1570～1610nm).The gating time is also improved by decreasing carrier lifetime.The wide band polarization insensitive SOA gate is promising for use in future dense wavelength division multiplexing (DWDM) communication systems.
