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 : 7 D& K8 o6 X; O0 r' W- e The doc spec write as below ,1 d; ]+ {& Q6 F& |+ J+ a# }
Frequency Emission Level% p8 B% g( _( U( b; M0 P+ @, V1 j
2Mhz to 50Mhz -30dbm/200khz % a; s3 |) H; O. ~5 W, i. T& L
a, e6 _' b8 n 1. what's it mean ? 7 D4 r+ C- \5 E( j8 i 2. How should I do when I measure spurious use Spectrum Analyzer ?" {6 q" c+ h5 A. e8 @* H
(ex: set RBW=200khz and measured spurious below -30dbm is pass ? 6 J3 W& E3 C) i& i8 Z9 } or others )' G9 A# f% i5 P3 `# y
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4 T& l! I: B* D; R 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.- w- u3 p9 }0 @7 P& Z
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 : 6 J3 G1 H' L! t7 h0 l Thanks your reply. . a/ G9 E. s7 E+ f0 r. | x4 y To confirm again , ! }5 C( r8 Y5 f! O 1. It means when I measure use Spectrum Analyser I need to set 6 O. D$ X! Z5 ]* t# q. J) x RBW=200Khz start=2Mhz stop=50Mhz,0 b8 D% ]) \) o* a3 X2 t1 E5 k1 K
if measured power level >-30dBm then it's fail , <-30dBm it's pass.9 e# A$ J" B' X6 x
Right ? 3 ]& F/ S$ I- \( ~8 _+ T* C/ O; \6 q) n/ A4 \. {
2. But my boss tell me it's need below -70dbm not -30dbm , I don't know why.7 Y# ]; J. t1 w; h
If I transfer it to dbm/hz is -83dmb/hz ,it become more severe than -70dbm I1 d" b) h* R1 T$ @; J* n
and unit also different.: t+ k$ t3 |: g3 p- v
I don't know which part is wrong ? - C$ k9 v8 q# W0 s+ Q: F 2 Y5 C9 P8 e& m( J Thanks.