電路板故障分析
維修方式介紹
ASA維修技術(shù)
ICT維修技術(shù)
沒有線路圖,無從修起
電路板太複雜,維修困難
維修經(jīng)驗及技術(shù)不足
無法維修的死板,廢棄可惜
送電中作動態(tài)維修,危險性極高
備份板太多,積壓資金
送國外維修費用高,維修時間長
對老化零件無從查起無法預(yù)先更換
維修速度及效率無法提升,造成公司負(fù)擔(dān),客戶埋怨
投資大量維修設(shè)備,操作複雜,績效不彰
標(biāo)簽：
電路板維修
技術(shù)資料
上傳時間：
2013-10-26
上傳用戶：neu_liyan
Single-Ended and Differential S-Parameters
Differential circuits have been important incommunication systems for many years. In the past,differential communication circuits operated at lowfrequencies, where they could be designed andanalyzed using lumped-element models andtechniques. With the frequency of operationincreasing beyond 1GHz, and above 1Gbps fordigital communications, this lumped-elementapproach is no longer valid, because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-element techniques.Scattering parameters, or S-parameters, have beendeveloped for this purpose [1]. These S-parametersare defined for single-ended networks. S-parameterscan be used to describe differential networks, but astrict definition was not developed until Bockelmanand others addressed this issue [2]. Bockelman’swork also included a study on how to adapt single-ended S-parameters for use with differential circuits[2]. This adaptation, called “mixed-mode S-parameters,” addresses differential and common-mode operation, as well as the conversion betweenthe two modes of operation.This application note will explain the use of single-ended and mixed-mode S-parameters, and the basicconcepts of microwave measurement calibration.
標(biāo)簽：
差分電路
單端
模式
上傳時間：
2014-03-25
上傳用戶：yyyyyyyyyy
