1、 - - - - - - - - ( ) 1 8563A SPECTRUM ANALYZER 9 kHz - 26.5 GHz 2 4 1 2 3 4 5 3 1 1 1 CW 2 AM FM PM 3 FSK QPSK QAM 4 2 1 2 Burst 3 2 3 3.1 1 2 3 CW (power) 3 ( )3 3.2 3 CW 3.3 CW 0.5f 0 2f 0 f 0 4 W dBm dBm 10 lg P(mw) / 1(mw) 1 2 n dB 1 1 FFT( ) ADC 2 2 / Log Amp Input signal display 3 3.6 (GHz) (G
2、Hz) 0 3 6 1 2 4 5 0 3 1 2 3 6 4 5 3.6 (GHz) 0 3 1 2 f IF f s LCD input A f f LO f s f s f s f LO - f s f LO + f LO 3.6 6.5 6.5 REF LEL ATT RBW VBW SWP RE F ATT 1dB 1 - Center SPAN 2 - Amplitude( ) 2.1 Ref level Atten scale/div 2.2 Ref level Atten Attenuator 1 2 3 ATT Auto ATT 2.3 RF 2.4 2.4 3 RBW (R
3、BW) 1 2 RBW RBW 3.1 RBW 3.2 RBW RBW SPAN 3.3 RBW . 3 dB 10 kHz 10 kHz RBW 3.4 3.5 RBW 3 dB BW 3 dB 60 dB 60 dB BW 60 dB BW 3 dB BW = 11 1 15 1 5 1 3.6 RBW=30 kHz RBW= 3 kHz RBW=30 kHz RBW= 3 kHz 3.7 RBW A=10 lg(RBW new /RBW old ) 4 VBW- 4.1 VBW 4.2 VBW RBW 5 Sweep Time 5.1. : 5.2. : 2 RBW Span k T S
4、weep SPAN RBW VBW 5.3 ! RBW 6 Marke 6.1 3dB ACPR 6.2 Peak Search 7 Detector Negative: Peak: Sample: “bins“ amplitude = = N i i AV u N U 1 1 = = N i i RMS u N U 1 2 1 AVG RMS 8 8.1 -50 dBc -50 dBc -40 dBc 1 2 8.2 9 + + + + ATT ATT 10 10.1 - RBW ATT VBW Video BW .01 Res BW 11 -113dBc/Hz 10KHz offset 1
5、2 TG 1 1.1 ( X +0.5%X +10%X + X1/2) Fs=NFLO FIF PLL VCO : ( X + X1/2) : Single Marker Example: 1% of 400 kHz span 15% of 3 kHz RBW 10 Hz residual error + _ 2 GHz 400 kHz span 3 kHz RBW Calculation: (2x10 Hz) x (1.3x10 /yr.ref.error) 9 -7 = = = = 260 Hz 4000 Hz 450 Hz 10 Hz 4720 Hz Total = 1.2 2. : 1
6、. R B W ADC 0.2 dB (f3 GHz) 0.5 dB 0.2 dB (0 to -70 dB) 0.2 dB RBW (RBW 100 kHz) 0.1 dB 0.55dB : 0.5 dB(f3GHz) (95 % 2 ) 1.3 2 2.1 1) Span RBW VBW Sweep time 2) Marker Measure 3) / Save/Recall Print Hardcopy FSP R3131A R3131A 2.2 2.2.1 L in L out L in L out dBm G=L out L in dB 2.2.2 ALC ALC L in L o
7、ut L 2max dBm ALC = L 2max dBm L in L out max max2.2.3 . L in L out IN OUT output input R-3131A dB 2.2.4. f 1 f 2 2f 1 -f 2 2f 2 -f 1 L in L out IN OUT f1 f2 4 f 1 f 2 f 2 -f 1 1MHz (f 1 +f 2 )/2 IM 3 = L 3 -L 1 (dBc) L 1 L 3 f 1 f 2 f (MHz) 2f 1 -f 2 2f 2 -f 1 L 3 -L 1 1 , 1 2 100V HPIB GBIP ATT CRT , , . , ,
