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October 20, 2011
Radar Seminar
1
Phase Noise
Signal Source Analyzer E5052B (+E5053A)
SSB is extracted from the frequency domain signal:
HzdBc
Power Carrier
sideband modulation phase one ofdensity Power
f
fP
PfL
C
)(
2
1)(
1 Hz
log (L( f ))
fc
log (P)
f
log ( f fc )
Single side band noise spectrum:L( f )
October 20, 2011
Radar Seminar
2
The SSB spectrum and the phase spectral density
).( enoughsmallisif
)(2
)(2
2
1
/
/1
)(
2
1)(
21
2
21
2
2
2
2
2
21
fSf
fSf
v
v
v
f
Rv
Rv
f
f
fP
PfL
rmsv
rms
Carrier
rmsNoise
Carrier
rmsNoise
C
Hzrad)(
HzdBc)(
HzdBc)(
2
21
21 fSfSfL V
vnoise
vcarrier
fct
Im(v)
Re(v)
HzV2
f
fvfS rms
v
)()(
2Voltage Spectral Density
Hzrad2
f
ffS
rms )()(
2Phase Spectral Density
October 20, 2011 Page 3
Signal Source Analyzer E5052B (+E5053A)
ALL-IN-ONE instrument : 6 basic functions in one box.
Baseband Noise AM Noise
PM Noise
Spectrum
Monitoring (~D15MHz)
VCO Test Transient Meas.
RF input
RF input
Vcontrol
Vsupply
RF input RF input
RF input
BB input
~26.5GHz
October 20, 2011
Radar Seminar
4
“Normal” PN / PLL method (Direct Homodyne)
Display
LPF ADC Signal
Processing
(FFT) MIX.
PLL L.O.
fRF fLO
fLO = fRF and the phase difference between two signals is kept at 90 deg (p/2 rad) by PLL operation.
Basic theory of operation ( for a single channel of E5052B)
Signal Source
Under Test
△p/2 rad
Scaling amp.
(Digital PLL)
time
fRF fLO
△p/2 rad
IF Gain
October 20, 2011
Radar Seminar
5
VCO Phase Noise - 800 MHz Band GSM VCO -
- 166 to -167 dBc/Hz
@ 20 MHz offset
October 20, 2011
Radar Seminar
6
Phase Noise - 1Ghz Carrier
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Radar Seminar
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October 20, 2011
Radar Seminar
8
Phase Noise - 2.5Ghz Carrier
Integrated Noise and Jitter Conversion
Band marker function is available for setting trace integration range (start/stop offset frequencies)
• Integ Noise: dBc/Hz
• RMS Noise: Rad, Deg
• RMS Jitter: sec
Phase Noise - 1.75Ghz Carrier
October 20, 2011
Radar Seminar
9
October 20, 2011
Radar Seminar
10
SSA Block Diagrams and Signal Paths
Correlation technique for noise floor reduction
MNNNN TUSmeas /)( 21...
Signal-source
Under Test DSP
Cross-correlation
(Correlation#=M)
Splitter
Measured noise : Nmeas
Two-channel Cross-Correlation Technique
CH1
CH2
internal system noise N1
internal system noise N2
Source noise :
NS.U.T.
M (number of correlation) 10 100 1,000 10,000
Noise reduction on (N1+N2) -5dB -10dB -15dB -20dB
Assuming N1 and N2 are uncorrelated.
October 20, 2011
Radar Seminar
12
October 20, 2011
Radar Seminar
13
October 20, 2011
Radar Seminar
14
Signal Generators @ 640MHz
October 20, 2011
Radar Seminar
15
Crystal Oscillator @10MHz
Without Cross-Correlation
With Cross-Correlation
October 20, 2011
Radar Seminar
16
Signal Generators @ 232MHz
October 20, 2011
Radar Seminar
17
“Wide” PN / Heterodyne (digital) discriminator method
Basic theory of operation (for a single channel of the E5052B)
BPF
MIX.
FLL
L.O.
fRF
fLO
fIF Signal Source
Under Test
Scaling amp.
(Frequency Locked Loop)
DSP
(FFT)
t
LPF
PM
noise
Digital Signal Processing
ADC
time
V1(t)
V2(t)
October 20, 2011
Radar Seminar
18
AM noise measurement
Basic theory of operation (for a single channel of the E5052B)
BPF
MIX.
FLL
L.O.
fRF
fLO
fIF Signal Source
Under Test
Scaling amp.
Note that a main signal still exists at this point !
(Frequency Locked Loop)
v
DSP
(FFT)
t
LPF
LPF
AM noise
Digital Signal Processing
ADC
time
V1(t)
V2(t)
October 20, 2011
Radar Seminar
19
“Normal” PN / PLL method (E5053A + E5052B)
Basic theory of operation (for a single channel of E5053A + E5052B)
BPF
MIX.
L.O.1
fRF
fLO1
Signal Source
Under Test fIF
Display
LPF ADC Signal
Processing
(FFT) MIX.
PLL
L.O.2
fLO2 Scaling amp.
(Digital PLL) △p/2 rad
fLO2 = fIF
The phase difference between two signals is kept at 90 deg (p/2 rad) due to PLL operation.
a very stable L.O.
(Frequency down converter)
(E5053A) (E5052B)
IF Gain
October 20, 2011
Radar Seminar
20
October 20, 2011
Radar Seminar
21
October 20, 2011
Radar Seminar
22
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Radar Seminar
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October 20, 2011
Radar Seminar
25
Baseband noise measurement
LPF
Baseband
input port
(BNC)
ADC
DC cut off filter (Low/High)
capacitors (1410uF/10uF)
50 Ohm Input Impedance
Basic theory of operation
LPF ADC
IF Gain
IF Gain
splitter
Min. frequency: 1Hz / 1kHz
Max. frequency: 100MHz
DSP
(FFT) 250MHz sampling
“Discharge DC Block Capacitor”
when reconnecting to low-voltage devices.
(DC block capacitor)
Caution!
VCO Freq, Power, DC Current Tester Mode
Measurement Results - 800 MHz Band GSM VCO -
Tester Mode
Frequency Counter
Power Meter
DC Current Meter
October 20, 2011
Radar Seminar
27
PLL Synthesizer Measurement Result - 1.75 GHz Synthesizer -
October 20, 2011
Radar Seminar
28
