铁磁和反铁磁双层膜中铁磁共振的研究

采用微磁学理论研究了铁磁/反铁磁双层膜中的铁磁共振现象.本模型将铁磁薄层抽象为一个单晶,具有立方磁晶各向异性和单轴磁晶各向异性,而反铁磁层视为厚度趋近于半无穷,且只有单轴磁晶各向异性.推导出了该系统的铁磁共振频率和频率谱宽度的解析式.数值计算表明,铁磁共振模式分两支,取决于立方磁晶各向异性.而界面的交换耦合,是磁易轴具有单向性的起因.     

MC145151在锁相电路中的应用

介绍MC145151的概貌,并结合NEC公司生产的HPB-1210FM立体声激励器中的锁相电路,说明它在实际中的应用。     

An error-correcting code for data broadcasting and its error-correction capability

By using the vertical blanking period of television signals, it is possible to transmit coded data such as teletext, newspaper, telesoftware, music score, etc. However, the quality of ordinary TV channels is very poor for digital communications and a powerful error-correcting code is required to reliably transmit coded data. From the results of simulations using error pattern data collected in field tests and the comparison of various error-correcting codes under many conditions, it has been determined that the shortened (272, 190) majority-logic decodable difference-set cyclic code is a suitable code for NTSC TV signals. Moreover, the decoding algorithm for this code has been improved in order to increase the error-correction capability and a new LSI with this function has been developed. By using error-correcting codes proposed to date for teletext, it has been difficult to obtain a page error rate (PER) of 10⁻¹in many measurement points. However, PERs of less than 10⁻² can be obtained in this system, even when random noise, ghost interference, or waveform distortion are present and bit error rates (BERs) are 10⁻². This paper also gives PERs according to the error-data collected in field tests and shows that the error-correction capability increased equivalently up to 11 error-bits in a 272-bit by improving the decoding algorithm and the results of indoor and outdoor tests.     

小型视频光端机的开发与应用

论述了视频光纤传输系统的工作原理,对光端机部分主要电路作了详细介绍,并给出了视频光端机的性能指标。     

并行接口铁电存储器FM1808及其应用

RAMTRON公司生产的并行接口高性能铁电存储器FM1808是NV -SRAM的理想替代产品。文中介绍了FM1808的性能特点、引脚功能和工作原理 ,同时重点介绍了铁电存储器的应用特点及与其它类型存储器之间的应用差别 ,给出了FM1808的设计应用要点     

大运高速公路调频同步广播规划方案初探

针对广播发展年，主要论述我省在高速公路沿线开播调频同步广播的重要意义，以及这一新技术的规划和技术方案的实施。     

相干光源的研制现状

本文叙述了近年来国外相干光源的研究及其进展。并对频谱线宽、FM 调制特性和波长可变特性作了介绍。     

HIGH-RESOLUTION 35GHz COHERENT LFM-CW RADAR FOR TWO-DIMENSIONAL IMAGING

This paper presents the system design and experimental results of a 35GHz coherent LFM-CW radar for use in near range two-dimensional imaging. Special techniques, including FM sweep linearization, range-segment processing, system background voltage suppression and dynamic range compression are also presented.     

MSM激光距离成像雷达系统设计与实验研究

阐述MSM激光距离成像雷达测距成像基本原理,设计并搭建了构成雷达系统核心的调频信号发生器、调幅激光发射器及MSM自混频探测电路,选取MSM探测器上某成像单元进行雷达测距性能及距离分辨率实验,验证了线性调频带宽约400 MHz时距离分辨率0.375 m的设计指标,为雷达样机下一步实现距离成像奠定了技术基础.     

基于调频广播无源定位的有效可定位区

基于调频广播无源定位实际相当于收发分置的双基地雷达,通过对有效可定位区定义的分析,从能量约束、误差约束两个方面着手,建立了基于调频广播无源定位有效可定位区的计算模型。运用栅格法求解模型,较好地解决了有效可定位区的绘制和估算问题。最后,对算法进行了仿真实验,分析了仿真结果。