Transcription of デシベル表示について - cdtlab.jp
1 2012 CDTL file: [ ] (dB) ** 1 2012- 2012 Cdtlab 1. (dB) (dB) 1 2 dB=10log 10log ( 2 1) dB 1 100 0 0 10 101 1 10 100 102 2 20 1000 103 3 30 10000 104 4 40 dB dl( = 1 10) ) 20 dB=20log( 2 1)
2 DB 1 100 0 0 10 101 1 20 100 102 2 40 1000 103 3 60 10000 104 4 80 dB ** 2 2012- 2012 Cdtlab dB dB 4 12 2 6 2 1012 3 1 100 0 1/ 2 -3 1/2 -6 1/4 -12 2. dB (dB) / / 1 2 3 G G=50 1000 10=500000=20log(500000)=114(dB) G=34(dB)+60(dB)+20(dB) 114114(dB) 3. dB dB 1/ 2 3dB 1 1 50 34dB 2 2 1000 60dB 3 3 10 20dB ** 3 2012- 2012 Cdtlab 3dB 2 6dB 6dB/oct oct octave 10 20dB 20dB/dec dec decade 4.
3 DB 1m V/m 1 V/m 0dB 5. dB dB dBd dB dBi dB dBi dBd ( ) dB SN ** 4 2012- 2012 Cdtlab S/N 10log ( )=20log( ) 7. NF Noise Figure / / S/N 20log( / / ) 8. dB dB dB dBm 1mW dB dBW 1W dB dB 1 V dB dB /m 1 /m dB dBi dB dBd dB ** 5 2012- 2012 Cdtlab ** 6 2012- 2012 Cdtlab CDTLab (Circuit Design Technology Laboratory)
