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 6 u. @; A6 q7 r4 K4 Z$ e 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 ) 2 X5 X9 a! _) i- W1 I5 | @- J* ]3 D6 X
- 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