高精度磁场式时栅传感器激励信号对测量误差的影响分析及系统设计

为提高磁场式时栅传感器测量精度,本文从理论上推导分析了时栅传感器激励信号源幅值和相位不一致产生的谐波成分对时栅传感器测量精度的影响,提出了一种基于DDS原理并采用完整闭环调节的高性能时栅激励信号源设计方案。以FPGA为微处理器,通过编程分频系统时钟,设置频率、相位控制字对DDS输出的信号频率、相位进行调节,使用增益控制器配合相位累加器实现相位到幅值精确转换。搭建了信号调理电路和信号反馈电路,通过实时对比反馈控制,解决了系统电路阻抗不匹配及干扰导致的激励信号相位不正交性和幅值不一致性的问题。实验结果表明：本文所设计的激励信号源输出信号幅值相对误差只有0.4%,正交性相对误差只有0.05%,并且采用该激励信号源,磁场式时栅传感器测角原始误差从±103.4"降低到了±20.3",有效抑制由于激励信号源幅值不一致和相位不正交带来的谐波误差。经修正后对极内角位移测量误差只有±1.3",整周角位移测量精度达到±2",满足高精度位移测量要求。     

基于应变式双参数倾斜仪的设计

为精确测量桩体在施工过程的倾斜角度,介绍一种基于电阻应变计式的双参数倾斜仪,阐述了倾斜仪的结构设计和工作原理;推导出倾斜角和方位角的数学模型。对放大电路及其信号变换电路进行硬件设计和软件编程。实验结果表明倾斜角在±10°范围内,其测量精度为0.04°;方位角在0°～360°范围内,其测量精度为2.253°,可以满足桩基础施工的技术要求。     

短波相控天线阵全数字射频相位测量系统设计

天线阵各阵元激励信号的相位测量系统是短波相控天线阵的重要组成部分。针对短波相控天线阵设计需要,提出一种全数字多通道短波射频信号相位测量系统,给出了系统设计原理和具体实现方法,分析了系统的测量延时和测量精度等关键性能参数。分析和实测结果表明,该系统的相位测量延时小于1 ms,相位测量误差小于±0.2°,能够满足短波相控天线阵的设计要求。     

基于CORDIC算法的360°角度传感器的设计

一维霍尔板型角度传感器无法测量0～360°的角度,采用4个霍尔器件的联合测角技术和CORDIC算法可实现0～360°范围内的角度测量。文章详细描述了4个霍尔器件联合测角技术的测角原理及实现算法,并引入了符号幅值表示法,即先利用正弦和余弦的幅值进行0°～90°范围内的反正切CORDIC运算,再根据正弦和余弦正负号(符号)的不同组合实现角度从0°～90°到0°～360°的映射。Modelsim平台仿真验证了该方法的准确度和精度,仿真误差小于0.01%,实测总误差不大于0.05°。     

基于全相位校正的六自由度电磁定位信号提取方法

接收信号的频率偏差是影响六自由度电磁定位系统精度的主要原因之一,分析表明采用函数拟合法提取信号将会使频偏的影响放大将近两个数量级.针对这一问题提出基于全相位校正的信号提取方法,该方法采用双窗apFFT时移相位差法抑制频偏,提高接收信号的幅值提取精度;利用信号的正交性、周期性,简化求解过程,便于方法硬件实现.将函数拟合法与所提方法进行MATLAB仿真实验比较,结果表明,所提方法在10 dB～50 dB的噪声环境下可有效降低幅值提取误差,将六自由度电磁定位系统的距离误差降低至0.03 cm以内、角度误差降低至0.2°以内.     

一种新型磁敏集成角度传感器及其测量系统

研制了一种无触点的十字形两维集成垂直霍尔器件 ,它对平行于芯片表面的磁场敏感。当与被测转角θ的物件轴向相连的径向永久磁铁转动时 ,传感器给出了相对于被测角度的两种信号电压 ,通过接口电路和PC机组成的非接触式测量系统把信号转换为转角θ。测试结果表明该角度传感器及其测量系统的测量精度在 0°～ 36 0°范围内可达± 1°     

基于AD8302的高精度幅相检测系统的设计

为了提高幅相测量精度、简化电路,扩展频率范围,介绍了一种用于RF/IF幅度和相位测量的AD8302芯片;并利用此芯片和单片机组成高精度幅相检测系统,主要是以实现两路模拟输入信号的相位差和幅度比测量为目的;并利用分频器、施密特触发器和D触发器组成相位极性判断电路,扩展相位测量范围为0～360°;该系统能精确测量两输入信号的幅度比和相位差,测试结果表明基于AD8302的幅相检测系统具有精度高、抗干扰能力强等优点.     

基于单片机的电容式角位移测量系统

介绍一种电容式角位移测量系统,它以电容传感器作为敏感元件,以89C51单片微机为控制核心。详细分析了电容式角位移传感器的结构、特点及工作原理,叙述了该系统的硬件框图及软件流程图,实验结果表明:在0°~90°测量范围内,系统的测量精度可以达到±0.05°。     

嵌入式时栅传感器高精度激励设计方法

介绍了嵌入式时栅传感器的基本原理,分析了两相激励信号不一致性主要是幅值不等和相位不正交对传感器测量精度的影响。基于DDS原理结合反馈控制设计了高精度的激励信号模块,采用反馈电路控制可程控放大电路调理两相信号幅值,实现了激励信号的幅值相等,基于闭环反馈控制直接修改数字激励信号实现了信号的相位正交。实验研究结果表明,采用这种闭环控制的方法,传感器短周期测角误差从±65″降低到±16″左右,常值误差基本消除,传感器精度大幅度提高。     

基于信息融合的移动机器人侧向定位的研究

超声波传感器的入射角对输出有很大的影响,通过实验分析了入射角对输出的影响。采用引入误差补偿因子的方法,标定了传感器的测量模型,使得测量精度大大提高。在此基础上,基于多源信息融合设计了3种移动机器人侧向定位模型。经实验比较证实,引入误差补偿因子的融合模型定位精度高,可以使得距离误差控制在±2.4mm,姿态角误差控制在±0.32°以内。最后,将该融合模型应用于移动机器人的实际控制中,距离误差为±3.7mm、姿态角误差为±0.58°,满足移动机器人定位精度的要求。     

10-26GHz CMOS六位数控衰减器设计与实现

为了使衰减器更好的适应相控阵系统对高集成度波束赋形电路的应用需求。基于55nm CMOS工艺,设计了一款具有低插入损耗、低附加相移特性的六位数控衰减器,该数控衰减器采用桥T和π型衰减结构级联而成,在10-26 GHz频率范围内实现步进为0.5dB、动态范围为0-31.5 dB的信号幅度衰减。为减小插入损耗,NMOS开关采用悬浮栅和悬浮衬底连接方式,同时采用了电容补偿网络和电感补偿以有效降低附加相移。仿真结果表明,在10-26GHz的频带范围内,该数控衰减器的插入损耗小于-7dB,输入/输出回波小于-10dB,附加相移小于±3°,所有衰减态的衰减误差均方根小于0.8dB,芯片的核心电路面积为0.36 mm×0.16 mm。     

基于FPGA的静电支承系统数字控制电路设计

设计了一种基于FPGA的静电支承系统数字控制电路,利用FPGA并行运算的优势提高运算速度和实时性。分析了A/D和D/A转换器分辨率对测控精度及量化噪声的影响,在此基础上选用了高精度A/D和D/A转换器以提高测控精度,降低量化噪声对检测信号的干扰。测试电路对直流和交流输入信号的响应,并用最小二乘法对误差进行校正和补偿,结果表明：电路对直流信号的测量误差在1mV以内;对频率1-500Hz范围内的交流信号幅值衰减最大为-0.092dB,相位滞后最大为-7°。     

A compact wideband balun design using double‐sided parallel strip lines with over 9:1 bandwidth

A simplified miniaturized wideband balun design covering (0.38‐3.5 GHz) is presented. The broadband balun structure occupies a small area of 20.7 mm × 20.8 mm. The balun is designed using low loss double‐sided parallel strip lines and is comprised of a two‐stage Wilkinson divider followed by loading, symmetrically, the two output ports. One port with a phase inverter circuit; while a very similar but non‐inverting circuit is placed in the other port for loading‐balance compensation. To realize the balun's function, different smooth transitions have been employed and were accounted for. The fabricated balun circuit demonstrated phase and amplitude imbalance of less than ±5° and ± 0.4 dB, respectively, over the band.     

X频段八波束接收组件的设计与实现

针对X频段多波束有源相控阵系统的高集成、小型化、多波束等需求,设计了一款高集成、小型化的瓦片式八波束接收组件,该组件基于多层印制板技术,纵向实现了众多有源器件以及八套波束合路网络高密度布局,实现了组件的高集成化;针对组件的八波束合成需求,基于Wilkinson功分器的形式设计了一款小型化的高效合路网络,在7.5-9 GHz范围内,其插入损耗小于13 dB,端口间隔离度小于-20 dB,输出驻波比小于1.2,通道间幅相一致性良好;为降低组件内部信号的传输损耗,对组件内部的垂直互联结构进行了建模分析,得到不同结构参数对其传输性能的影响,通过优化结构参数的方法实现信号的低损耗传输。在此基础上对组件进行了加工实现,经测试,在7.5-9 GHz范围内,组件输出通道增益大于18 dB,输出驻波比小于1.5,通道间相位一致性小于±5°,尺寸仅有80 mm × 80 mm × 7.66 mm。     

A broadband out‐of‐phase gysel power divider based on a dual‐band circuit with a single fixed isolation resistor

Based on the double‐sided parallel‐strip lines with an inserted conductor as a virtual ground, a high power divider with dual‐band/broadband response and frequency‐independent 180° phase difference between the output ports is implemented in this paper. The circuit topology employs a single commercially available external isolation resistor as well as moderate line impedances (15–100 ohm), making it suitable for high‐power applications. Precise closed‐form design equations on the basis of even‐ and odd‐mode analysis are derived. In addition to the wide range of frequency band ratios from 1 to 2.65, broadband response is also obtained by selecting the proper value of frequency band ratios. To substantiate the design equations and theory, a circuit with 2:1 frequency ratio and 84.5% bandwidth referring to 16 dB isolation and 12 dB return loss values is developed. To the authors' knowledge, this is the widest bandwidth reported for out‐of‐phase high power dividers. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2016.     

Accurate and efficient design technique for wideband substrate integrated waveguide directional couplers

In this article, we present an efficient technique for the accurate design of wideband substrate integrate waveguide directional couplers. By tapering the coupling section, the bandwidth of substrate integrated waveguide (SIW) directional couplers can be enlarged. Two design aspects are involved in this approach. First, the even‐mode propagation constant in the tapered coupling section is accurately extracted with the help of a numerical thru‐reflect‐line calibration technique. Then, it is fitted into the model of a uniform dielectric‐filled rectangular waveguide and thereafter extrapolated to the operation range of the odd mode. Second, equivalent circuit models of the waveguide bifurcation effects are also presented together with parametric values. Based on the results of extraction, a 90° 3‐dB directional coupler is developed to validate the proposed design approach. To achieve the reverse phasing at two output ports, the prototyped 90° 3‐dB directional coupler is subsequently integrated with a novel broadband fixed phase shifter developed with the SIW technology, of which a systematic synthesis procedure has been proposed in this article. Measured performance of both 90° and 180° 3‐dB couplers confirms the accuracy of our proposed design approach. This kind of wide‐band directional coupler can find applications in wideband power dividing/combining circuits within a single‐layer platform. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

硅微陀螺带通ΣΔ闭环检测环路设计

本文研究了SDM调制器在陀螺闭环检测中的应用,主要针对其闭环检测的结构设计和参数获取作了相应的研究和阐述。硅微机械陀螺敏感模态为二阶模态,基于SDM调制器的设计原理,结合DSToolbox来设计整个闭环检测电路,得到闭环检测电路的结构和参数。最终仿真得到的闭环检测系统的信噪比达到了106 dB。在量程为±200°/s,带宽为200 Hz时,分辨率可以达到0.001°/s。     

A dual‐band branch line coupler for LTE 0.7 GHz and LTE 2.6 GHz frequencies

In this paper, a dual‐band branch line coupler (BLC) for Long Term Evolution (LTE) 0.7 GHz and LTE 2.6 GHz frequencies is designed and developed. A dual‐band quarter wave transmission line (DBQWTL) capable to perform dual band operation for frequency ratio >3 is also proposed. The dual band BLC is designed by replacing the quarter wave transmission line of the conventional single band BLC with the proposed DBQWTL. By means of even and odd mode analysis, the closed form design equations of the proposed DBQWTL are obtained. Considering the implementation viewpoint of the proposed BLC, the circuit parameter analysis is carried out. The proposed BLC performs dual band operation with maximum amplitude imbalance of 0.26 dB and phase deviation of 3.07°. It is found in the comparative analysis that the proposed BLC has novelty in terms of its operating frequency ratio range.     

Reconfigurable multibeam feed network for 38 GHz application

A feed network based on substrate integrated waveguide for 38 GHz application is proposed in this article. The network consists of a 90° hybrid, a 180° hybrid, a power divider, and a switchable phase shifter. There are two input ports in the reconfigurable multibeam feed network (RMBFN) and a set of symmetrical radiation pattern will be excited by the two input ports. In addition, the other symmetrical patterns will be obtained by adjusting the different states of the switchable phase shifter. The simulated results show that the S₁₁ and S₂₂ are found to be better than ?13 dB over 37‐40 GHz. Meanwhile, the amplitude of the three output ports is about ?6.6 ± 1 dB, and the phase difference is ±60 ± 10° or ±120 ± 10°. When the proposed RMBFN feeds for an antenna array, four different beams with the main beam pointing to the ±22 ± 3° and ±43 ± 3° are obtained.