SDH/PDH分析儀抖動發生器的校準

詹志強 陸福敏

上海市計量測試技術研究院

摘　要:本本文介紹了上海市計量測試技術研究院建立的有線數字通信檢測裝置中SDH／PDH分析儀抖動發生器校準系統，本系統可以校準高達10Gbit／s的電口和光口的抖動發生器輸出抖動，所使用的標準儀器為頻譜分析儀、75Ω／50Ω阻抗變換器和用于光輸出信號抖動校準的O／E轉換器。校準方法為Bessel函數的比值法和寬帶調頻法，對于小抖動值，則使用Bessel函數比值法：而對于JJG（YD）044—1998SDH數字傳輸分析儀檢定規程中所需要校準的10UIp-p的抖動，則使用寬帶調頻法與比值法相結合。用NI公司的Labview軟件編寫了抖動自動測試軟件，通過與信息產業部通信計量中心對同一臺裝置同一組數據的校準結果比較，表明二者之間相當一致，證明了本抖動發生器校準系統方案設計合理，計量準確可靠。[著者文摘]


An automatic jitter calibration system for jitter generator accuracy in SDH/PDH analyzerZhan Zhiqiang, Lu Fumin Shanghai Institute of Measurement ＆ Testing Technology Shanghai, 200233, ChinaAbstract:This article introduces the calibration system of jitter generator used in SDH/PDH analyzer which is part of the digital wire communication measurement system built at Shanghai Institute of Measurement ＆ Testing Technology （SIMT）, As high as 10Gbit/s jitter output of the jitter generator with either electrical or optical port can be calibrated with the system, the instruments utilized include E4440 spectrum analyzer,75Ω/50 Ω impedance adapter and 83440C O/E converter dedicated for jitter calibration of optical output signal. Ratio of Bessel Function and Wide-band FM （WBFM） are adopted as calibration approaches, for small jitter value Ratio of Bessel Function approach is used whereas the combination of Ratio of Bessel Function and WBFM approach is used when calibrating the 10Ulp-p jitter accuracy required by JJG （YD） 044-1998 Regulation of Verification for SDH Transmission Analyzer. Automatic measurement software was also made with Labview from NI to improve measurement efficiency. The measurement results were compared with the same group of results from the same equipment measured by Metrology and Calibration Center of MII, the conclusion is that they are quite close to each other, which approves that the approach to realize the calibration system is rational and credible and the results are accurate and reliable.[著者文摘]

Key words:jitter; calibration; SDH/PDH transmission analyzer; jitter generator; Bessel Function; WBFM.