Study of the evanescent wave coupled semiconductor quantum dot amplifying fiber

Optical amplifiers are the key parts in many fiber-optic transmission systems such as fiber CATV network, subscribe access network and some military fields. Amplifying fiber i the core part in an optical amplifier, and till now most ampli fying fibers in …     

基于双模开环谐振器的双频带滤波器设计

基于开环双模谐振器设计了一种双频带通滤波器,由两个中心重合的正方形开口环谐振器组成。分析该谐振器的奇偶模谐振频率与传输零点,每个通带内有两个谐振模式。该滤波器中心频率分别为4.5 GHz和6.5 GHz,3 dB相对带宽FBW分别为11%、5%,两通带带内插入损耗分别小于0.6 dB、1.4 dB,带内回波损耗分别优于19.5 dB、16.5 dB,高频处阻带抑制达到50 dB,两通带之间隔离度达到53 dB,尺寸仅为6 mm×11 mm×1.09 mm。     

Waveguide polarizer based on resonant tunneling

A novel and highly efficient waveguide polarizer which is based on the phenomenon of resonant tunneling is proposed. Designs for both transverse-electric (TE) and transverse-magnetic (TM) pass polarizers based on this principle are suggested, and it is shown that with such a device it is possible to achieve TM mode loss greater than 80 dB/mm and TE mode loss less than 0.5 dB/mm for the TE pass polarizer, and TE mode loss of 24 dB/mm with a TM mode loss less than 0.8 dB/mm for the TM pass polarizer     

平坦通带高频纵向耦合谐振滤波器的研制

应用耦合膜理论,重点研究了纵向耦合谐振滤波器耦合换能器与输入/输出换能器间距对纵向耦合谐振滤波器通带波纹的影响,探讨了制作纵向耦合谐振滤波器中金属铝的干法刻蚀工艺。基于理论模拟得出的结论,文中给出了中心频率为900MHz纵向耦合谐振滤波器频率响应的计算模拟结果和实验测试数据。测得1dB带宽25.9MHz,3dB带宽28.7MHz,阻带抑制达到50dB,插入损耗3.85dB,通带波纹小于0.7dB。实验结果与理论分析相吻合。     

2R-Regeneration of an 80-Gb/s RZ-DQPSK Signal by a Nonlinear Amplifying Loop Mirror

The performance of a nonlinear amplifying loop mirror as a 2R-regenerator for an 80-Gb/s return-to-zero differential-quadrature-phase-shift-keyed signal has been investigated experimentally. A significant eye-opening improvement and a negative power penalty of up to 2.6 dB were obtained.     

Resonant Meta-Surface Superstrate for Single and Multifrequency Dipole Antenna Arrays

The design of a multifrequency dipole antenna array based on a resonant meta-surface superstrate is proposed. The behavior of a single element that is closely placed to a meta-surface is experimentally investigated. The proposed meta-surface is based on resonating unit cells formed by capacitively loaded strips and split ring resonators. By tuning a dipole antenna to the pass band of the meta-surface, the physical area is effectively illuminated enhancing the radiation performance. The gain, radiation efficiency and effective area values of the whole configuration are compared to the ones obtained with a single dipole without superstrate. Radiation efficiency values for the proposed configuration of more than 80% and gain values of more than 4.5 plusmn 1 dB are obtained. Based on this configuration, simulated results of a multifrequency antenna array are presented. Distinctive features of this configuration are high isolation between elements (20 dB for a distance of lambda₀/4), and low back radiation.     

基于ADS的平衡式低噪声放大器设计

平衡放大技术有着驻波特性好,增益高、易级联的优点。本文将平衡放大技术应用到低噪声放大器的设计中,在保证低噪声和功率增益的同时,用以提高低噪声放大器的驻波比和增益平坦度。ADS仿真结果表明,在5.3-6.3 GHz的频带范围内,低噪声放大器绝对稳定,噪声系数≤1.182 dB,功率增益达到10 dB,并且通过采用平衡放大技术,输入输出驻波比≤1.3∶1,带内波动≤1dB,提高了低噪声放大器的有效工作带宽。     

基于PBG结构的双模带通滤波器设计及理论分析

本文应用传输线理论对PBG结构带通滤波器进行分析,并在此基础上仿真、设计一种新颖的K波段的双模带通滤波器.光子带隙结构具有独特的带阻特性,对高次模具有很好的抑制特性,能够提高微波电路系统的抗干扰能力.由于PBG的慢波特性,使得带通滤波器的结构尺寸大为减小,符合系统小型化的要求.在此基础上,就这种结构应用Ensemble软件进行优化仿真.最后制作出滤波器并进行了测试.仿真结果与实验结果吻合很好,插入损耗为-4.5dB,通带中心频率为25.2GHz,-3dB带宽为1.8GHz,相对带宽7%.     

S-band erbium-doped silica fibre amplifier with flattened-gain ofover 21 dB

A gain-flattened erbium-doped silica fibre amplifier (EDSFA) has been developed for amplifying WDM signals in the S-band. The EDSFA exhibits a signal gain of over 21 dB, a gain excursion of less than 1.9 dB, and a noise figure of less than 6.7 dB in the 1491-1518 nm wavelength range     

Acoustically tunable wavelength filter with gain

The first integrated optical amplifying acoustically tunable wavelength filter in Er-doped LiNbO₃ is reported. At the signal wavelength of λ_s=1531 nm a maximum gain of 4.8 dB has been obtained with a coupled pump power of 160 mW (λ_p =1484 nm). Lossless signal transmittance has been achieved with a pump power as low as 13.5 mW for λ_s>1561 nm     

Low-loss straight and curved ridge waveguides in LPE-grown GaInAsP

Loss measurements on ridge waveguides in LPE-grown GaInAsP at a wavelength of 1.3 mu m are presented. An attenuation of 4.5 dB/cm has been obtained for straight waveguides, and for curved waveguides an excess loss at low as 0.7 dB was found for a 20.8 degrees S-bend with a radius of 300 mu m ( approximately=1.5 dB/90 degrees ).<>     

一种用于射频接收机的模拟基带电路

设计了一种无线传感网射频接收机中的基带电路,包括滤波器和可变增益放大器(VGA)。滤波器采用5阶切比雪夫型有源RC结构,带宽可调,具有自动调谐功能,能适应制造工艺与环境条件的变化。VGA由2阶放大器与1阶缓冲器组成,每阶放大器拥有一个DCOC环路,用来抑制直流失调,减小增益瞬态变化的稳定时间。采用TSMC 130 nm CMOS工艺进行流片。测试结果表明,供电电压为1.3 V时,滤波器能够涵盖8种带宽。自动调谐模块的调谐范围为±20%,调谐精度为2%。接收机的IIP3为28 dBm,双边带噪声为3 dB。VGA的增益变化范围为-12~56 dB。当VGA的增益瞬态变化量为32 dB时,DCOC的稳定时间小于100 ns。     

Concept of multiport-coupling beam-switching network and its basic performance in K-band

The letter reports the concept of a new switching/amplifying network, and its basic performance, for scanning the down-link beam rapidly in multibeam satellite systems. Experiments in the K-band have shown 85% power-combining efficiency, more than 17 dB isolation and 400 ns switching speed.     

Loss-compensated optical Y-branch switch in InGaAsP-InP

An InGaAsP-InP loss-compensated Y-branch switch is demonstrated. Integrated amplifying sections compensate for internal losses. The operating wavelength is 1.3 μm, and the gating dynamic range is 35 dB. A study of similar devices indicates that a gain of more than 10 dB and a gating dynamic range in excess of 45 dB are feasible     

PECVD grown multiple core planar waveguides with extremely lowinterface reflections and losses

A novel and generic method for fabricating silica-on-silicon planar lightwave circuits with cores composed of two or more different types of glasses is described. The basic process technologies used are silane/germane/nitrous-oxide based plasma enhanced chemical vapor deposition and fluorine based reactive ion etching. Very high-quality interfaces between the different core glasses are obtained with interface losses as low as 0.022±0.012 dB and reflection levels below -80 dB. This technique adds flexibility and ease to the design of complex silica planar waveguide components, allowing, e.g., independent optimization of amplifying and passive sections in lossless devices based on erbium-doped planar waveguides     

Er3+-doped cladding fibres and their taper componentapplications

A biconical taper amplifier utilizing an Er³⁺-doped cladding fiber is discussed. A maximum gain of 0.6 dB in a 2.4-Gb/s optical transmission experiment was obtained with a taper about 40 mm long. This result shows the potential of a new structure for Er³⁺ -doped coupling and amplifying components     

Wideband traveling-wave tube for a X/Ku-band vacuum solid-state amplifier

Results of the numerical simulation of the slow-wave structure and the electron-optical system of a wideband continuous-wave traveling-wave tube with an output power of 250 W and gain of 23 dB, which is designed for operation in an X/Ku-band vacuum solid-state amplifying module, are given.     

High-power microwave amplifier using IMPATT diodes

A single multichip IMPATT diode, operating in the unconditional amplifying mode, has been used as a reflection amplifier in the 6?8 GHz range. C.W. power-output levels of 4.0 W have been achieved with a stable reflection-amplifier circuit, using two multichip diodes in separate cavities coupled to a single circulator through an airstrip hybrid. The gain of the amplifier is 6 dB, with 250 MHz (?1 dB) bandwidth.     

Digitally-controlled automatic gain control circuits for CMOS CCDcamera interface

Automatic gain control circuit (AGC) design techniques for CMOS CCD camera interface systems are described. The required gain of the proposed AGC is controlled directly by digital bits. The amplifying function of the AGC is divided into three stages for high-speed operation. A capacitor-segment combination technique considerably improves the effective bandwidth of the AGC. While the three-stage prototype shows 32 dB AGC dynamic range in 1/8 dB steps, the proposed two-stage AGC reduces the power and chip area further     

声表面波纵向耦合谐振滤波器通带特性研究

在理论方面,作者应用COM理论分析研究了纵向耦合谐振滤波器通带波纹大小和耦合换能器与输入/输出换能器间距离的关系。在工艺上,作者采用剥离工艺制作了相应的纵向耦合谐振滤波器,并给出了所设计的纵向耦合谐振滤波器频率响应的测试结果。实验测得样品滤波器中心频率为895 MHz,1 dB带宽40.5 MHz,阻带抑制达到47 dB,插入损耗3.8 dB,通带波纹小于0.9 dB。实验与理论分析比较一致。