標題: about dbm/200khz problem.. [打印本頁] 作者: super 時間: 2009-5-22 10:32 PM 標題: about dbm/200khz problem.. Dear all :# {% f' [2 [$ k: g8 X- h) f
The doc spec write as below , / ^$ f% _ B R% ?* ~' D Frequency Emission Level+ e+ G2 h; Q, L
2Mhz to 50Mhz -30dbm/200khz , K- r+ r x' M7 P$ D' G3 }# Y
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1. what's it mean ?' l9 _& G9 z6 k2 v7 n
2. How should I do when I measure spurious use Spectrum Analyzer ?3 M3 k" X( e) }
(ex: set RBW=200khz and measured spurious below -30dbm is pass ? t( e% J. @ k or others )4 P( K ~9 y" I0 b9 u
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Thanks.作者: cqmyg5 時間: 2009-5-23 08:05 AM
I'm not an expert, I think "set RBW=200khz and measured spurious below -30dbm is pass" is correct.+ |) K1 b/ x5 H/ \& X
I know another spec: -40dBm/1MHz, that's to measure dBm per 100k(RBW=100k)., then sum(10), if below -40dBm is pass.作者: super 時間: 2009-5-24 07:41 PM
Dear sir : + e2 d+ {: J0 A+ U8 ~ Thanks your reply. $ \ Y, Z: c; Y9 ?# p9 G To confirm again , 1 L. u$ q$ [+ i; e2 A5 T2 z# o 1. It means when I measure use Spectrum Analyser I need to set * p' \8 v' j2 s, [, K% t1 C
RBW=200Khz start=2Mhz stop=50Mhz, ( z& L( V% a3 l1 T0 n if measured power level >-30dBm then it's fail , <-30dBm it's pass. k/ [5 V6 E6 ?8 }/ o Right ? . m& x6 Y/ W" n8 v8 P- b+ |2 Z# W) ]- L: C. @5 g, f8 L
2. But my boss tell me it's need below -70dbm not -30dbm , I don't know why., Z5 Y( k8 |6 s+ |8 S! U$ @
If I transfer it to dbm/hz is -83dmb/hz ,it become more severe than -70dbm * x q4 ~) K+ F) ]8 X8 y and unit also different.; ?8 K9 h" I9 N1 m s
I don't know which part is wrong ?, o# ^% G& _* ~+ M: H
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Thanks.