深空测控通信中需在大带宽内对多个目标信号同时进行无误码解调,且极端应用场景中大信号与极微弱信号同时存在。要实现多目标强弱信号全频谱同时采集,要求模拟数字转换器(Analog to Digital Converter,ADC)的无杂散动态范围(Spurious Fr...深空测控通信中需在大带宽内对多个目标信号同时进行无误码解调,且极端应用场景中大信号与极微弱信号同时存在。要实现多目标强弱信号全频谱同时采集,要求模拟数字转换器(Analog to Digital Converter,ADC)的无杂散动态范围(Spurious Free Dynamic Range,SFDR)性能尽可能的高。提升SFDR性能需要从系统各个层面进行优化设计,采取关键技术手段,才可达到预期的结果。该文分析了影响ADC的SFDR性能各个因素,并采取频谱规划设计、功率规划设计、电源优化设计、时钟电路优化设计、差分驱动电路优化等综合设计手段,从而实现最佳采样。展开更多
This paper proposes a method to improve the spu-rious-free dynamic ranges(SFDRs)of 1-bit sampled signals greatly,which is very beneficial to multi-tone signals detection.Firstly,the relationship between the fundamenta...This paper proposes a method to improve the spu-rious-free dynamic ranges(SFDRs)of 1-bit sampled signals greatly,which is very beneficial to multi-tone signals detection.Firstly,the relationship between the fundamental component and the third harmonic component of 1-bit sampled signals is analyzed for determining four contiguous special frequency bands,which do not contain any third harmonics inside and co-ver 77.8%of the whole Nyquist sampling frequency band.Then,we present a special 4-channel monobit receiver model,where appropriate filter banks are used to obtain four desired pass bands before 1-bit quantization and each channel can sample and process sampled data independently to achieve a good in-stantaneous dynamic range without sacrificing the real-time per-formance or computing resources.The simulation results show that the proposed method effectively eliminates the effect of the most harmonics on SFDRs and the mean SFDR is increased to to 20 dB.Besides,the multi-signals simulation results indicate that the maximum amplitude separation(dynamic range)of two signals in each channel is 12 dB while the proposed monobit re-ceiver can deal with up to eight simultaneous arrival signals.In general,the designing method proposed in this paper has a po-tential engineering value.展开更多
Integrated high-linearity modulators are crucial for high dynamic-range microwave photonic(MWP)systems.Conventional linearization schemes usually involve the fine tuning of radio-frequency(RF)power distribution,which ...Integrated high-linearity modulators are crucial for high dynamic-range microwave photonic(MWP)systems.Conventional linearization schemes usually involve the fine tuning of radio-frequency(RF)power distribution,which is rather inconvenient for practical applications and can hardly be implemented on the integrated photonics chip.In this paper,we propose an elegant scheme to linearize a silicon-based modulator in which the active tuning of RF power is eliminated.The device consists of two carrier-depletion-based Mach-Zehnder modulators(MZMs),which are connected in series by a 1×2 thermal optical switch(OS).The OS is used to adjust the ratio between the modulation depths of the two sub-MZMs.Under a proper ratio,the complementary third-order intermodulation distortion(IMD3)of the two sub-MZMs can effectively cancel each other out.The measured spurious-free dynamic ranges for IMD3 are 131,127,118,110,and 109 d B·Hz^(6∕7)at frequencies of 1,10,20,30,and 40 GHz,respectively,which represent the highest linearities ever reached by the integrated modulator chips on all available material platforms.展开更多
分析了目前分段电流舵数模转换器（DAC）在动态性能提升和芯片面积缩小等方面的局限性。提出了动态元件匹配（DEM）译码技术。设计了16 bit DAC中的DEM译码电路结构,分析了DEM译码技术的原理。对该16 bit DAC的动态性能等进行了详细仿真...分析了目前分段电流舵数模转换器（DAC）在动态性能提升和芯片面积缩小等方面的局限性。提出了动态元件匹配（DEM）译码技术。设计了16 bit DAC中的DEM译码电路结构,分析了DEM译码技术的原理。对该16 bit DAC的动态性能等进行了详细仿真,并完成了整体版图设计。该DAC核心部分芯片面积仅为2. 2 mm^2。采用0. 18μm CMOS工艺完成了该DAC的加工和性能参数测试。在1 GHz采样率和100 MHz输入信号频率条件下,该DAC的无杂散动态范围约为67 dB,三阶互调失真约为76 dB,整体性能优于目前同类研究成果。展开更多
文摘深空测控通信中需在大带宽内对多个目标信号同时进行无误码解调,且极端应用场景中大信号与极微弱信号同时存在。要实现多目标强弱信号全频谱同时采集,要求模拟数字转换器(Analog to Digital Converter,ADC)的无杂散动态范围(Spurious Free Dynamic Range,SFDR)性能尽可能的高。提升SFDR性能需要从系统各个层面进行优化设计,采取关键技术手段,才可达到预期的结果。该文分析了影响ADC的SFDR性能各个因素,并采取频谱规划设计、功率规划设计、电源优化设计、时钟电路优化设计、差分驱动电路优化等综合设计手段,从而实现最佳采样。
文摘This paper proposes a method to improve the spu-rious-free dynamic ranges(SFDRs)of 1-bit sampled signals greatly,which is very beneficial to multi-tone signals detection.Firstly,the relationship between the fundamental component and the third harmonic component of 1-bit sampled signals is analyzed for determining four contiguous special frequency bands,which do not contain any third harmonics inside and co-ver 77.8%of the whole Nyquist sampling frequency band.Then,we present a special 4-channel monobit receiver model,where appropriate filter banks are used to obtain four desired pass bands before 1-bit quantization and each channel can sample and process sampled data independently to achieve a good in-stantaneous dynamic range without sacrificing the real-time per-formance or computing resources.The simulation results show that the proposed method effectively eliminates the effect of the most harmonics on SFDRs and the mean SFDR is increased to to 20 dB.Besides,the multi-signals simulation results indicate that the maximum amplitude separation(dynamic range)of two signals in each channel is 12 dB while the proposed monobit re-ceiver can deal with up to eight simultaneous arrival signals.In general,the designing method proposed in this paper has a po-tential engineering value.
基金National Natural Science Foundation of China(62305303,62205164)Science and Technology Plan Project of Zhejiang(2022C01108)。
文摘Integrated high-linearity modulators are crucial for high dynamic-range microwave photonic(MWP)systems.Conventional linearization schemes usually involve the fine tuning of radio-frequency(RF)power distribution,which is rather inconvenient for practical applications and can hardly be implemented on the integrated photonics chip.In this paper,we propose an elegant scheme to linearize a silicon-based modulator in which the active tuning of RF power is eliminated.The device consists of two carrier-depletion-based Mach-Zehnder modulators(MZMs),which are connected in series by a 1×2 thermal optical switch(OS).The OS is used to adjust the ratio between the modulation depths of the two sub-MZMs.Under a proper ratio,the complementary third-order intermodulation distortion(IMD3)of the two sub-MZMs can effectively cancel each other out.The measured spurious-free dynamic ranges for IMD3 are 131,127,118,110,and 109 d B·Hz^(6∕7)at frequencies of 1,10,20,30,and 40 GHz,respectively,which represent the highest linearities ever reached by the integrated modulator chips on all available material platforms.
