A 2.4GHz 0.18μm CMOS gain-switched single-end Low Noise Amplifier （LNA） and a passive mixer with no external balun for near-zero-IF （Intermediate Frequency）/RF （Radio Frequency） applications are described. The ...A 2.4GHz 0.18μm CMOS gain-switched single-end Low Noise Amplifier （LNA） and a passive mixer with no external balun for near-zero-IF （Intermediate Frequency）/RF （Radio Frequency） applications are described. The LNA, fabricated in the 0.18μm 1P6M CMOS technology, adopts a gain-switched technique to increase the linearity and enlarge the dynamic range. The mixer is an IQ-based passive topology. Measurements of the CMOS chip are performed on the FR-4 PCB and the input is matched to 50Ω. Combining LNA and mixer, the front-end measured performances in high gain state are： -15dB of Sll, 18.5dB of voltage gain, 4.6dB of noise figure, 15dBm of IIP3, 85dBm to -10dBm dynamic range. The full circuit drains 6mA from a 1.8V supply.展开更多
We present a method of generating high dynamic range(HDR)radiance maps from a single low dynamic range(LDR)image and its camera response function(CRF).The method first models and estimates the inverse CRF and then mul...We present a method of generating high dynamic range(HDR)radiance maps from a single low dynamic range(LDR)image and its camera response function(CRF).The method first models and estimates the inverse CRF and then multiplies the inverse CRF by a weighting function to make it smooth near the maximum and minimum pixel values,and finally conducts the smooth inverse CRF on the input LDR image to generate HDR image.In the method,the inverse CRF is estimated using one single LDR image and an empirical model of CRF,based on measured RGB distributions at color edges.Unlike most existing methods,the proposed method expands image from both high and low luminance regions.Thus,the algorithm can avoid the artifacts and detail loss in dark area which results from extending image only from bright region.Extensive experimental results show that the approach induces less contrast distortion and produces high visual quality HDR image.展开更多
Increasing bandwidth requirements have posed significant challenges for traditional access networks.It is difficult for intensity modulation/direct detection to meet the power budget and flexibility requirements of th...Increasing bandwidth requirements have posed significant challenges for traditional access networks.It is difficult for intensity modulation/direct detection to meet the power budget and flexibility requirements of the next-generation passive optical network(PON)at 100G and beyond considering the new requirements.This is driving researchers to develop novel optical access technologies.Low-cost,wide-coverage,and high-flexibility coherent PON is emerging as a strong contender in the competition.In this article,we will review technologies that reduce the complexity of coherent PON(CPON),enabling it to meet the commercial requirements.Also,advanced algorithms and architectures that can enhance system coverage and flexibility are also discussed.展开更多
文摘A 2.4GHz 0.18μm CMOS gain-switched single-end Low Noise Amplifier （LNA） and a passive mixer with no external balun for near-zero-IF （Intermediate Frequency）/RF （Radio Frequency） applications are described. The LNA, fabricated in the 0.18μm 1P6M CMOS technology, adopts a gain-switched technique to increase the linearity and enlarge the dynamic range. The mixer is an IQ-based passive topology. Measurements of the CMOS chip are performed on the FR-4 PCB and the input is matched to 50Ω. Combining LNA and mixer, the front-end measured performances in high gain state are： -15dB of Sll, 18.5dB of voltage gain, 4.6dB of noise figure, 15dBm of IIP3, 85dBm to -10dBm dynamic range. The full circuit drains 6mA from a 1.8V supply.
基金supported by the National Natural Science Foundation of China (61401072)
文摘We present a method of generating high dynamic range(HDR)radiance maps from a single low dynamic range(LDR)image and its camera response function(CRF).The method first models and estimates the inverse CRF and then multiplies the inverse CRF by a weighting function to make it smooth near the maximum and minimum pixel values,and finally conducts the smooth inverse CRF on the input LDR image to generate HDR image.In the method,the inverse CRF is estimated using one single LDR image and an empirical model of CRF,based on measured RGB distributions at color edges.Unlike most existing methods,the proposed method expands image from both high and low luminance regions.Thus,the algorithm can avoid the artifacts and detail loss in dark area which results from extending image only from bright region.Extensive experimental results show that the approach induces less contrast distortion and produces high visual quality HDR image.
基金supported in part by the National Key Research and Development Program of China(No.2023YFB2905700)in part by the National Natural Science Foundation of China(Nos.62171137,62235005,and 61925104)in part by the Natural Science Foundation of Shanghai(No.21ZR1408700)。
文摘Increasing bandwidth requirements have posed significant challenges for traditional access networks.It is difficult for intensity modulation/direct detection to meet the power budget and flexibility requirements of the next-generation passive optical network(PON)at 100G and beyond considering the new requirements.This is driving researchers to develop novel optical access technologies.Low-cost,wide-coverage,and high-flexibility coherent PON is emerging as a strong contender in the competition.In this article,we will review technologies that reduce the complexity of coherent PON(CPON),enabling it to meet the commercial requirements.Also,advanced algorithms and architectures that can enhance system coverage and flexibility are also discussed.
文摘提出了基于异构双核的低场核磁共振(Low-field Nuclear Magnetic Resonance,low-field NMR)接收机的设计,具有ARM(Adanced RISC Machines)和现场可编程门阵列(Field Programmable Gate Array,FPGA)先进的异构双核结构、高速的模数转换器(Analog to Digital Converter,ADC)采集、增益的可控以及可视化显示等特性,提高了整个系统的性能指标.设计中采用Xilinx公司的系统开发工具System Generator来实现内部信号处理功能.实验结果表明,数字接收机具有结构紧凑、可重构性强、采样速率高和成本低等特点,并且增益的可控使接收机获得了较大的动态范围,提高了重建图像的信噪比(Signal-to-Noise Ratio,SNR).
