微波宽带低噪声放大器的设计研究

微波宽带放大器是电力对抗、遥测遥控和雷达等进行系统接收的关键部件,宽带网络设计作为微波宽带设计中的难点内容,需要充分运用负反馈和平衡电路的形式,来降低宽带低噪声的匹配难度,要想促进微波宽带低噪声放大器取得良好的应用效果,需要合理设置微波宽带低噪声放大器.本文对微波宽带低噪声放大器基本理论进行详细阐述,并提出了设计方法.     

集成宽频带低噪声晶体管放大器

本文围绕晶体管宽频带放大器的设计,简单介绍了晶体管的性能。讨论了晶体管宽带放大器的两种设计方法。通过管芯载体以及π型高通匹配电路的应用,研制出10～1000兆赫低噪声宽频带集成晶体管放大器、20～2000兆赫集成宽带晶体管放大器和2000～4000兆赫集成宽带放大器。给出了性能指标。     

iTerra Communications开发出高功率GaAs MMIC放大器

iTerra Communications公司开发出一种封装宽带GaAs MMIC行波放大器,在2~18GHz的宽带宽频率范围内,其饱和RF输出功率电平高。这种GaAs-MMIC行波放大器适用于宽带测试设备、电子战与电子对抗系统,以及任何要求高宽带增益和高输出功率的应用领域。该放大器的制造采用了少量外部元     

WJ推出新的高线性宽带放大器

WJ Communication新近推出了一种新的高线性宽带放大器。其型号为SCG002的这种宽带放大器是其高可靠性、低成本增益锁定放大器系列中的最新产品，适用于现有和下一代基站。     

拉曼+EDFA宽带混合光放大器的实现和设计优化

基于对增益和噪声特性的分析,本文实现了长距离宽带传输系统中由分布拉曼放大器和掺铒光纤放大器中组成的宽带混合放大单元,并提出了混合放大器进行优化设计的方法,特别指出适当调整拉曼放大器和掺铒光纤放大器的增益谱可以实现噪声谱的平坦.     

宽带增益平坦光结Raman放大器的研究进展

宽带增益平坦光放大器是密集波分复用光通信系统提高信息容量的基本需求,在总结宽带掺铒光纤放大器的基础上,介绍了展宽光纤Raman放大器平坦增益带宽的基本方法和研究现状。     

宽带、超宽带光纤放大器研究进展

目前,实现宽带、超宽带光纤放大器的技术主要有四种:宽带掺铒光纤放大(EDFA)技术、宽带拉曼放大技术、宽带混合放大技术和光纤参量放大技术.综述了宽带和超宽带光纤放大器的研究现状,并分别分析了其特点及发展趋势.     

宽带增益平坦光纤Raman放大器的研究进展

宽带增益平坦光放大器是密集波分复用光通信系统提高信息容量的基本需求。在总结宽带掺铒光纤放大器的基础上 ,介绍了展宽光纤Raman放大器平坦增益带宽的基本方法和研究现状。     

基于宽带高增益的放大器设计

文中介绍了一种基于集成运算放大器实现的宽带高增益放大器,本系统创造性地利用两级宽带运放VCA822压控放大,宽带运算放大器OPA690输出,完成了一个通频带50 kHz~40 MHz,增益0~68 dB可调的宽带高增益放大器。放大器噪声小,通频带范围宽,最大放大倍数大,后级加入了开关手动切换的自动增益控制电路模块,自制电源降压模块。系统采用多种方式消除了高增益,高频自激。放大器输入输出阻抗均为50Ω,方便和前后级电路匹配。     

基于GaN HEMT 器件的宽带高效功率放大器

介绍一种宽带高效放大器设计方法,并基于GaN HEMT器件研制了宽带高效功率放大器。采用源牵引和负载牵引方法获得适应宽带条件的最佳源阻抗和负载阻抗,然后综合宽带匹配网络并实现测试电路设计。实测结果表明,该放大器在0.9～2.7GHz工作频带范围内,放大器输出功率均大于10W,工作效率在51%～72%之间,增益大于13dB。为改善放大器线性度指标,采用商用预失真芯片搭建简单的预失真电路对放大器进行线性化校正,并给出了详细的测试结果。     

Broad-Band Parametric Amplifier Design (Correspondence)

A computerized optimization technique is employed to provide design values for broad-band parametric amplifiers. Some results of the procedure are presented.     

Receiver Front-End Circuits for Future Generations of Wireless Communications

In this paper, new receiver concepts and CMOS circuits for future wireless communications applications are introduced. The concepts derived are applied to a few classes of wireless communications standards that are broad-band at radio frequencies and/or require a broad-band baseband circuitry. Multimode multiband operation and adaptivity as key requirements for future generation receivers are highlighted throughout the paper. The tradeoffs between power consumption, noise figure and linearity performance of low-noise amplifiers, mixers, and intermediate frequency filters are considered too.     

Development of Integrated Broad-Band CMOS Low-Noise Amplifiers

This paper presents a systematic design methodology for broad-band CMOS low-noise amplifiers (LNAs). The feedback technique is proposed to attain a better design tradeoff between gain and noise. The network synthesis is adopted for the implementation of broad-band matching networks. The sloped interstage matching is used for gain compensation. A fully integrated ultra-wide-band 0.18-mum CMOS LNA is developed following the design methodology. The measured noise figure is lower than 3.8 dB from 3 to 7.5 GHz, resulting in the excellent average noise figure of 3.48 dB. Operated on a 1.8-V supply, the LNA delivers 19.1-dB power gain and dissipates 32 mW of power. The gain-bandwidth product of the UWB LNA reaches 358 GHz, the record number for the 0.18-m CMOS broad-band amplifiers. The total chip size of the CMOS UWB LNA is 1.37 times 1.19 mm².     

A GaAs monolithic low-noise broad-band amplifier

Describes the design, fabrication, and performance of GaAs monolithic low-noise broad-band amplifiers intended for broadcast receiver antenna amplifier, IF amplifier, and instrumentation applications. The process technology includes the use of Czochralski-grown semiinsulating substrates, localized implantation of ohmic and FET channel regions, and silicon nitride for passivation and MIM capacitors. The amplifiers employ shunt feedback to obtain input matching and flat broad-band response. One amplifier provides a gain of 24 dB, bandwidth of 930 Mhz, and noise figure of 5.0 dB. A second amplifier provides a gain of 17 dB, bandwidth of 1400 MHz, and noise figure of 5.6 dB. Input and output VSWR's are typically less than 2:1 and the third-order intercept points are 28 and 32 dB, respectively. Improved noise figure and intercept point can be achieved by the use of external RF chokes.     

Computer-Aided Design of Broad-Band Amplifiers with Complex Loads

A computer-aided design approach is developed for the analysis and design of broad-band amplifiers with complex terminations, e.g., an antenna. The transfer scattering parameters are used for the analysis of a cascade connection of distributed lines and amplifiers. A modified version of Rosenbrock's minimization procedure is used to find the optimum lengths and characteristic impedances of the lines which minimize the reflection losses and realize a desired gain characteristic. Several examples are given.     

Design Techniques and Intermodulation Analysis of Broad-Band Solid-State Power Amplifiers

This paper presents balanced circuit techniques for the reduction and cancellation of the dominating third-order intermodulation tion product generated by broad-band solid-state power amplifiers. These techniques are applicable to collocated transmitters where the interference enters through the output port of the transmitter. A rigorous derivation is presented to prove the validity of the intermodulation canceliation by using a quadrature-hybrid coupling scheme in a balanced circuit configuration. The results are valid for arbitrary nonlinear characteristics exhibited by general classes of amplifiers, as well as isolators.     

On the noise properties of linear and nonlinear quantum-dot semiconductor optical amplifiers: the impact of inhomogeneously broadened gain and fast carrier dynamics

We present a detailed analytical model describing the noise properties of quantum-dot (QD) optical amplifiers operating in the linear and saturated regimes. We describe the dependence of the optical noise on the main physical parameters characterizing the QD gain medium as well as on operating conditions. The optical noise at the amplifier output shows a broad-band spectrum with an incoherent spectral hole due to the gain inhomogeneity. A coherent spectral dip stemming from noise-signal nonlinear interactions is superimposed on that broad-band spectrum. The broad-band incoherent component is also calculated using an approximate model which makes use of an equivalent inhomogeneous population inversion factor. The validity of the approximation is examined in detail. We also calculate the electrical relative intensity noise and observe a spectral hole corresponding to the spectral shape of the optical noise. The most important characteristics of the optical and electrical noise spectra are determined by the degree of inhomogeneous broadening and by the fast carrier dynamics of QD amplifiers. The fast dynamics causes a very wide noise spectral hole which has important potential consequences for detection of fast data and for all optical signal processing.     

Broad-band continuous-wave-pumped fiber optical parametricamplifier with 49-dB gain and wavelength-conversion efficiency

A broad-band continuous-wave (CW) pumped fiber-based parametric amplifier with 39 dB of internal gain and wavelength conversion efficiency, corresponding to a black box gain/efficiency of 38 dB, is demonstrated. Bit-error-rate (BER) measurements indicate performance comparable to erbium-doped fiber amplifiers (EDFAs). These amplifiers may thus find new applications in future lightwave systems     

Microwave Integrated Tunnel-Diode Amplifiers for Broad-Band High-Performance Receivers

The design and development of microwave integrated-circuit (MIC) tunnel-diode amplifiers for use in integrated broad-band high-performance receivers is described. In particular, this paper describes the design, construction, and performance of thin-film microstrip tunnel-diode amplifiers operating in the 8-to 12- and 6-to 8-GHz bands, respectively, with noise figures in the 5-to 7-dB range.