Chip123 科技應用創新平台

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 :
/ e) l- i& i( G7 l8 I+ E               The doc spec write as below ," ~, U: T2 ?! L& R
                   Frequency         Emission Level
- I7 T3 j. w/ Q" E! m                2Mhz to 50Mhz    -30dbm/200khz ) I+ ^, ?. @0 B# C
# s2 S1 y& b2 w' Y9 _0 X7 X
             1. what's it mean ?
$ D! W: e8 a9 K  H) r! J/ H1 j- q             2. How should I do when I measure spurious use Spectrum Analyzer ?1 {1 b9 O# l8 j+ Y# ?/ E" H- F- {
            (ex: set RBW=200khz  and measured spurious below -30dbm is pass ?
1 @# \. ~2 U% |  c! S                   or others )
- o& Q- L0 H" A3 e' p) ]; L/ p/ E
4 U% s0 {5 @2 W' s
              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.
" z4 Q* Y2 e, QI 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 :
- i( l( R/ B# K( [+ ~. {9 p           Thanks your reply.2 U3 ^  o5 H$ b4 N0 C
            To confirm again , % f' B% `* C( I( m
          1. It means when I measure use Spectrum Analyser I need to set
& K* k( r5 [* t' \7 T3 J  k              RBW=200Khz start=2Mhz stop=50Mhz,
; d2 ~. F: Q) Y; \8 V             if measured power level >-30dBm then it's fail , <-30dBm it's pass.6 i2 c8 [- R9 T4 }# g
              Right ?; j5 E8 |, G( C3 U7 z

% R  M8 h4 q1 q. L& `          2. But my boss tell me it's need below -70dbm not -30dbm , I don't know why.
8 S4 Q. ~9 w  y" [" R             If I transfer it to dbm/hz is -83dmb/hz ,it become more severe than -70dbm
7 W( G  Q7 k  g( k* M' B             and unit also different.
) i2 F2 y2 k! A' S1 C6 x0 J3 X             I don't know which part is wrong ?: ?2 V7 f3 g5 K5 I

' N% ~" ~+ m3 C; ]0 N           Thanks.




歡迎光臨 Chip123 科技應用創新平台 (http://www.chip123.com.tw/) Powered by Discuz! X3.2