Bandwidth enhancement of the monopole antenna by using a parasitic normal-mode helix

An innovative monopole antenna coupled with a parasitic normal-mode helix has been designed and studied both experimentally and theoretically. The effects of various dimensions of the monopole and the parasitic helix were investigated extensively. This simple combination can significantly enhance the antenna bandwidth over that of the conventional monopole antenna. It is found that, with suitably chosen antenna dimensions, the VSWR bandwidth (VSWR ≤ 2) of the antenna can be increased to 36%, almost double that of the monopole antenna alone. The far-field pattern of the combined antenna is basically the same as that of the monopole antenna. This antenna is designed to operate at 1.8GHz. The substantially enhanced bandwidth of this simple and small antenna is a useful feature for future mobile communications.     

HVDC用低噪声电容器研制

从高压直流输电(HVDC)电容器噪声产生的基本规律出发,从声学原理的角度分析,提出了抑制电容器噪声的方法,取得了一些实际的经验,其中振动消能装置、隔音腔等单元降噪方法已经应用于工程实际并获得了国家专利。本文首先对弹簧减振器和共振吸声器进行了理论分析,得到共振型降噪措施的降噪效果不好的结论。噪声测试表明,在电容器单元底盖两端增加隔音腔是目前电容器噪声治理的最有效办法。     

光伏型InSb红外探测器低噪声前放设计

以光伏型InSb红外探测器输出的微弱电流信号为依据对探测器的前置放大电路进行设计,并采用ORCAD电路仿真软件对所设计的低噪声、高增益放大电路的幅频响应、温度特性以及噪声进行了全面的分析和仿真。研究结果表明,该设计可以有效地提高信噪比和输出动态范围。     

A 65-nm low-noise low-cost ∑ △ modulator for audio applications

This paper introduces a low-noise low-cost ∑ △ modulator for digital audio analog-to-digital conversion.By adopting a low-noise large-output swing operation amplifier,not only is the flicker noise grea...     

宽频带低噪声放大器的设计

随着光纤通信、卫星通信向着宽频带方向发展,要求放大器的带宽也就越来越宽。文中设计了一种低噪声放大器,该放大器具有较低的噪声系数,同时工作频带较宽。增益平坦度在工作频段内控制在约1 dB,另外该低噪声放大器的输入输出匹配和稳定性良好。     

1V高线性度2.4GHz CMOS低噪声放大器

讨论了低噪声放大器(LNA)在低电压、低功耗条件下的噪声优化及线性度提高技术.使用Chartered 0.25μm RF CMOS 工艺设计一个低电压折叠式共源共栅LNA.后仿真结果表明在1V电源下,2.36GHz处的噪声系数NF仅有1.32dB,正向增益S21为14.27dB,反射参数S11、S12、S22分别为 -20.65dB、-30.27dB、-24dB,1dB压缩点为-13.0dBm,三阶交调点IIP3为-0.06dBm,消耗的电流为8.19mA.     

Design of a 40-GHz LNA in 0.13-μm SiGe BiCMOS

A low-noise amplifier(LNA)operated at 40 GHz is designed.An improved cascode configuration is proposed and the design of matching networks is presented.Short-circuited coplanar waveguides(CPWs)were used as inductors to achieve a high Q-factor.The circuit was fabricated in a 0.13-μm SiGe BiCMOS technology with a transistor transit frequency fT of 103GHz.The chip area is 0.21mm2.The LNA has one cascode stage with a-3dB bandwidth from 34 to 44GHz.At 40GHz,the measured gain is 8.6dB;the input return loss,S11,is...     

Design and analysis of a UWB low-noise amplifier in the 0.18 μm CMOS process

An ultra-wideband (3.1-10.6 GHz) low-noise amplifier using the 0.18 μm CMOS process is presented. It employs a wideband filter for impedance matching. The current-reused technique is adopted to lower the power consumption. The noise contributions of the second-order and third-order Chebyshev fliers for input matching are analyzed and compared in detail. The measured power gain is 12.4-14.5 dB within the bandwidth. NF ranged from 4.2 to 5.4 dB in 3.1-10.6 GHz. Good input matching is achieved over the entire bandwidth. The test chip consumes 9 mW (without output buffer for measurement) with a 1.8 V power supply and occupies 0.88 mm2.     

锗硅低噪声放大器的研究进展

介绍了采用锗硅技术的低噪声放大器的基本理论,给出了一个2GHz低噪声放大器的例子,并总结了近来采用锗硅技术的各种频段的低噪声放大器研究情况.最后,介绍了锗硅技术的广阔应用前景.     

基于最小噪声匹配的低噪放-天线一体化电路

传统的接收端天线与低噪声放大器(LNA)级联,通常需将天线输出阻抗与LNA的输入阻抗均匹配到50 Ω,为此引入的匹配电路不仅占用了较大的电路尺寸,而且额外引入插入和失配等损耗.为消除匹配网络,本文提出一种基于ATF-54143晶体管的低噪放-天线一体化电路,基于最小噪声条件下将天线的阻抗与LNA晶体管的输入阻抗实现匹配...