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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 :9 m2 e) c. X4 t! V4 Q( x
               The doc spec write as below ,
4 I! f; K2 u' ^) N+ w- F                   Frequency         Emission Level
$ Z5 ^0 t& Z  M                2Mhz to 50Mhz    -30dbm/200khz
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9 J; b& s. N8 O' D7 r1 p8 _) ]             1. what's it mean ?
8 i3 r8 L9 k9 p- S             2. How should I do when I measure spurious use Spectrum Analyzer ?
! \& f. J+ g9 a- x4 s6 _            (ex: set RBW=200khz  and measured spurious below -30dbm is pass ?7 A! N2 I, W$ g2 R
                   or others )
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- m5 o5 [" D0 p8 x$ B6 j2 u# S$ n: W              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.( p% o+ n( J/ R; q0 I; H) T
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 :3 O- ]$ J, R+ q2 i! a
           Thanks your reply.
1 k* }& O1 w, j% n# E            To confirm again ,
3 |% }8 G5 T/ J0 f          1. It means when I measure use Spectrum Analyser I need to set
- v9 `) ?2 k& z  o9 g# Y; {              RBW=200Khz start=2Mhz stop=50Mhz,- z% v. g! O* P3 }0 f, v" a' F& n
             if measured power level >-30dBm then it's fail , <-30dBm it's pass.
6 S8 H4 v6 k0 V; S* ^' @              Right ?; G" H9 @5 k0 [3 g& D; R5 |) F  P1 y

" L) P7 o: B8 @# Z5 c, z          2. But my boss tell me it's need below -70dbm not -30dbm , I don't know why.
7 z* i) c4 g. [0 T, Y. [/ {             If I transfer it to dbm/hz is -83dmb/hz ,it become more severe than -70dbm' U& Q( z7 p  S: B! I
             and unit also different., s" }/ ]! k! H$ ]4 |1 H" T# `; Y
             I don't know which part is wrong ?& e: s4 y1 K6 ]# @) b

1 e6 v2 y% R) d: `9 e9 |           Thanks.




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