基于Sagnac环的光纤围栏报警系统

应用Sagnac干涉的不稳定现象,设计了一种新型的报警方案-光纤围栏.简单介绍了光纤围栏的工作原理,实验装置及建立实验装置时的主要工作.利用VC设计示波器,进行光强变化的接收模拟实验;具体进行了硬件电路的铺设、解调方案的设计,完成实验装置系统.     

一种光纤Mach-Zehnder干涉仪的相位补偿方案

针对光纤Mach-Zehnder干涉（MZI）受环境影响的稳定性问题,设计了光纤MZI实验装置。从理论上分析了光纤MZI的输出光强,并给出了实验验证,由示波器直观地显示出光纤MZI的稳定性与环境的关系以及相位调制对干涉的影响等。为了解决振动噪声、温度变化等环境因素导致的光纤MZI不稳定,设计了一种新的相位补偿方案,即用两个2×2光纤耦合器的输出,实现相差检测及反馈控制。     

光纤光栅振动传感解调方法的研究

光纤光栅振动传感是光纤光栅的重要应用之一。本文首先介绍了光纤光栅传感的一般原理,接下来综述了5种常用的振动传感的解调方法及原理,并分别给出了其典型的实验装置结构图,分析了其特点和性能（尤其是测量精度）,为基于光纤光栅的振动传感装置的解调部分的设计提供了依据。     

音频信号数字化光纤传输实验仪信道的设计与实现

介绍音频信号数字通信实验装置设计的实现过程,该装置以FPGA为主控芯片,以光纤为通讯媒介,将音频信号数字化后通过光纤实现传输,并对电路各个模块的功能及实现加以说明。实验装置采用分模块式的设计,设计思路灵活,结构清晰。电路在Altium Designer和Protel99中设计完成,并且在QuartusⅡ环境下用VerilogHDL语言进行编程并对程序进行仿真。该装置已做成了实体,可以实现音频信号的发射与接收,达到设计提出的要求。     

抗压低衰减光纤气密封转接装置的研制

针对贯穿密闭容器的抗高压光纤气密封转接装置,通过改进转接装置制作工艺,采用裸光纤灌胶密封,设计两端带光纤定位套保护的灌胶筒,灌封胶分次注入等措施,有效地降低了密封转接装置对传输光信号的衰减。检测结果表明:所研制的抗压低衰减光纤气密封转接装置实验样品,在满足密闭容器超压冲击实验密封要求(容器内外压差2MPa,气体漏率小于10-7 Pa·m3/s)的情况下,在密封转接段的光信号衰减小于1dB。     

基于CO2激光的双包层光纤端帽熔接实验研究

光纤端帽可以有效避免高峰值功率下脉冲双包层光纤激光器的光纤端面损伤。为了实现大直径双包层光纤端帽的低成本制作,设计并搭建了基于CO2激光的光纤端帽熔接实验系统,研究了光纤端帽的熔接方法和工艺,利用熔接好端帽的双包层掺镱光纤进行了高功率脉冲光纤激光放大器的实验,验证了光纤端帽的实际使用效果。实验结果表明,本装置可以实现高质量、低成本的双包层光纤端帽熔接。采用此方法熔接的光纤端帽可以显著提高光纤的损伤阈值,同时基本不影响激光输出效率以及光束质量。     

光斑光强渐变测量通信光纤数值孔径

数值孔径NA(Numerical Aperture)是通信光纤的一个重要光学参数,表征了光纤的集光能力.它与光纤传输系数的计量有密切关系,对通信光纤的传输带宽有很大影响.光纤数值孔径的测量方法有多种,文中设计了一种用于通信光纤数值孔径快速测量的装置,该装置包括光源、刻度旋转台、微调机构及数字仪表等单元,测量基于光斑光强渐变机理,根据仪表显示值在临界点突变可确定被测光纤的数值孔径,实验表明该装置测量稳定可靠,多次测量平均值的重复性优于2%.     

一种可调谐掺铒光纤激光器的研究

文章基于掺铒光纤在1 550 nm波段的增益特性,利用光纤光栅作为调谐装置,设计了可调谐光纤光栅激光器的简单结构,通过改变光纤光栅的温度对光纤激光嚣的波长进行了调谐.更重要的是实验分析了不同掺铒光纤长度对激光输出功率的影响,在温度为25℃时,实验中分别取10、20和30 m 3种不同光纤长度进行了测试,结果表明,不同长度的掺铒光纤,其阀值不同.     

基于七芯光纤的高温传感器优化与设计

设计了一种新型高温传感装置,将一段七芯光纤耦合在两段单模光纤之间,发射光进入到七芯光纤中,在透射光谱范围内产生周期性调制的超模干涉图案,其频谱偏移随温度变化而改变,实现了实时监测.该传感装置制造简单,实验证明在温度高达1000℃的环境下仍可稳定工作.     

保偏光纤环形谐振腔研究

报道了一种用于角速度测量的光纤谐振式传感器保偏光纤环形谐振腔的研究,给出了测量的原理、实验装置和实验结果.根据计算和实验结果,对影响系统性能的几个重要光学参数进行了设计和优化.该谐振腔已在传感器系统中得到应用.     

A 4-bit CMOS Phase Shifter Using Distributed Active Switches

This paper presents a novel 4-bit phase shifter using distributed active switches in 0.18-mum RF CMOS technology. The relative phase shift, which varies from 0deg to 360deg in steps of 22.5deg, is achieved with a 3-bit distributed phase shifter and a 180deg high-pass/low-pass phase shifter. The distributed phase shifter is implemented using distributed active switches that consist of a periodic placement of series inductors and cascode transistors, thereby obtaining linear phase shift versus frequency with a digital control. The design guideline of the distributed phase shifter is presented. The 4-bit phase shifter achieves 3.5 plusmn 0.5 dB of gain, with an rms phase error of 2.6deg at a center frequency of 12.1 GHz. The input and output return losses are less than -15 dB at all conditions. The chip size is 1880 mum times 915 mum including the probing pads.     

Frequency domain detection of coherence multiplexed sensor signalsby using an optical loop with a frequency shifter

We describe a frequency domain detection scheme of coherence multiplexed sensor signals by using an optical loop with a frequency shifter. The optical path differences of the sensors are adjusted to integer-multiple of the loop length of the optical loop, and then the the sensor signals are multiplexed in the frequency domain, appearing at the integer-multiple of the working frequency of the frequency shifter. In the experiment, four Michelson-type sensors are successfully multiplexed with the sensitivities of about 2 mrad/√Hz. The sensitivities are also theoretically calculated which are in good agreement with the experimental results. The optimum design of the optical loop is also discussed     

一种X波段五位数字移相器的研究与设计

介绍了数字移相器的基本原理及设计方法。在ADS仿真环境下,基于GaAs HJ—FET开关器件,设计仿真了一种X波段五位数字移相器,大大降低了移相器的后期制作成本。利用矢量网络分析仪对制作的实物进行了测试,结果表明：在12—12．5GHz频段内,移相器的最大插损小于9．5dB,均方根相位误差在3°以内。     

360°模拟移相器平衡插入损耗和拓宽频带的研究

本文论证了用电阻补偿法平衡360°模拟移相器插入损耗波动的正确性,并推导出确定移相器频带宽度的目标函数,籍CAD给出移相器在最大带宽条件下的有关设计参量,通过直观曲线为选择变容二极管作理论依据。采用微波集成电路工艺制作的模拟移相器在1．3～2．1GHz范围内可获得360°连续可变相移,最大调相电压18V,中心频率线性度优于±2．5％,插入损耗波动小于3dB。     

A K-Band Low-Power Phase Shifter Based on Injection Locked Oscillator in 0.13 μm CMOS Technology

In this paper, the design challenges of the injection-locked oscillator (ILO)-based phase shifter are reviewed and analyzed. The key design considerations such as the operating frequency, locking range, and linearity of the phase shifters are analysed in detail. It is possible to optimize the phase shifter in certain parameters such as ultra-low power while meeting the requirements of a certain system. As a design example, a K-band phase shifter is implemented using a commercial 0.13 μm CMOS technology, where a conventional LC tank based topology is implemented but optimised with a good balance among power consumption, working range, sensitivity, and silicon area, etc. Measurement results show that the proposed phase shift is able to work at 22–23.4 GHz with a range of 180^° while consuming 3.14 mW from a 1.2 V supply voltage.     

Design of novel wideband reflective phase shifters with wide range of phase applications

This paper presents wideband compact differential reflective phase shifter based on the double layer slot-coupled coupler configuration. This novel phase shifter arrangement consists of a 3-dB hybrid coupler with the coupled and transmission ports terminated with rectangular and elliptically shaped microstrip loads. By altering the ports termination of the coupler, phase shifters propose differential phase ranging from −90° to +90° over 1.3–5.9G Hz frequency band. To achieve different range of phase performance, the proper reactance is calculated at the outputs of coupler. These reactances are transformed to the elliptical or rectangular-shaped microstrip load with various dimensions for every phase shifter. The calculation and simulations results show that the developed circuits could provide ±30°, ±60°, ±45° and ±90° differential phase shifts. For verification of this wideband phase shifter design method, two phase shifter example with rectangular and elliptical load termination is fabricated and measured. The measured return loss of the phase shifter with elliptically load is better than 10 dB over 1.3–5.9G Hz frequency band as well as insertion loss is less than 1 dB. The phase shift deviation is less than 2.1°. The results demonstrate that the proposed phase shifters are well suited for use in GPS/LTE/WiMax/WLAN frequency bands.     

A 170 GHz 45$^{circ}$ Hybrid for Submillimeter Wave Sideband Separating Subharmonic Mixers

We present a 135deg/45deg phase shifter hybrid intended to be used in subharmonic sideband separation mixer schemes at submillimeter-wave frequencies. The design consists of an increased height 90deg 6-arm branch guide coupler with a three stub loaded differential line 45deg phase shifter at the output. The device has been implemented at G-band in an E-plane WR-05 splitblock design with a center frequency of 170 GHz and 15 % bandwidth. Measured S-parameter are in good agreement with simulations showing an isolation and return loss better than 20 dB and an amplitude and phase imbalance within 0.4 dB and 2deg, respectively.     

一种新型BST薄膜移相器的电路设计

采用铁电材料钛酸锶钡(BST)的薄膜移相器以其成本低廉、响应速度快、频带宽、体积小、重量轻、控制简单等诸多优点而引起关注.本文对BST薄膜移相器的设计模型进行研究分析,提出了一种新型的电路结构,在BST材料移相器的大移相量和尽可能低的损耗一对矛盾中找到一个平衡点.并通过ADS仿真验证了这一新型电路.     

Distributed MEMS analog phase shifter with enhanced tuning

The design, fabrication, and measurement of a tunable microwave phase shifter is described. The phase shifter combines two techniques: a distributed capacitance transmission line phase shifter, and a large tuning range radio frequency (RF) microelectromechanical system (MEMS) capacitor. The resulting device is a large bandwidth, continuously tunable, low-loss phase shifter, with state-of-the-art performance. Measurements indicate analog tuning of 170/spl deg/ phase shift per dB loss is possible at 40 GHz, with a 538/spl deg/ phase shift per centimeter. The structure is realized with high-Q MEMS varactors, capable of tuning C/sub max//C/sub min/= 3.4. To our knowledge, this presents the lowest loss analog millimeter wave phase shifter performance to date.     

五位RF MEMS开关延迟线移相器

设计并研制了一种6～11GHz、超宽带5位RF MEMS开关延迟线移相器,器件实现了5位延迟:λ、2λ、4λ、8λ、16λ。该器件采用微带混合介质多层板技术,分4层制作,尺寸为45mm×20 mm。整个器件包括20个RFMEMS悬臂梁开关,用60～75V的静电压驱动。6～11GHz频带内,对32个相移态的测试结果表明:一般回波损耗S11<-10dB,各状态平均插入损耗为-8～-10dB;中心频率处,器件可实现的最大延迟位时延为1680ps,总时延为3255ps。