Phase Noise and Noise Measurement Pengcheng Jia Nov 21, 2002
Sth New Phase Noise Measurement with PSA
(precision spectrum analyzer)
Mode->Phase Noise->LogPlotMode->Phase Noise->LogPlot
But pay attention to noise floor of the PSA. You can use noise floor cancellation function or use the HP11848 Phase noise system
Phase Noise Origins
• 1/f Noise of Semiconductor Transistor1/f Noise of Semiconductor Transistor
• DC Bias related noise (Shot Noise)DC Bias related noise (Shot Noise)
• Thermal Noise from ResistorsThermal Noise from Resistors
- Phase shifter is used to achieve quadrature
- Attenuator is used to keep input power at required level
- Phase noise of source will not affect residual noise of DUT when quadrature is achieved
11848 Phase Noise Interface
3561A Dynamic Signal Analyzer0.01Hz 100KHz
GPIB Control
Source
Phase ShifterPower Spliter
DUT
G=18dB
20 dB Attenuator
+8dBm
+10dBm
L Port
R Port
Residual Noise Measurement
3048A Phase Noise Software
Tiger is the 3048A system controller Start in MS-Dos Mode At the command prompt, enter c:\go Select 13 as the printer type and 0 as
the screen mode. The other settings are user preference
Now you are at c:\noise\3048> Run cal.exe for calibration and PN.exe
for measurement
Instrument Addresses Run PN.exe, Main Menu->System-
>InstrumentInstrument Model AddressFFT Analyzer 3561A 712RF Analyzer 8567A 718 (optional for offset from 100K to
40MHz)
Signal Srce 1Signal Srce 2Down Converter 11729C 706 (optional)
Getting system ready Functional Checks Quick Check Performance checks Calibrations
Read appendix for the time and sequence of calibration
Run PN.exe
1.Type of measurement->Phase noise without using PLL (for residual phase noise measurement)
Start/Stop frequency are the offset frequency from the carrier
2. ParametersInput carrier frequency and select
detector
Continue… Instrument controlSelect system connections Define graphConfigure the displayed graph System configuration->Instruments
addresses->Input addresses
File System Test file DirectorySave all the configurations for the measurement Result file directorySave the measurement result in this directory***Always choose this directory before you ***Always choose this directory before you
save your result, otherwise you only save save your result, otherwise you only save the configurations, not the data!!!the configurations, not the data!!!
Run Read_res.exe to convert *.res file to Run Read_res.exe to convert *.res file to data file which can be used in graph tools.data file which can be used in graph tools.
Go to mishrayork web->document for the Go to mishrayork web->document for the file.file.
Calibration-operation For the first time, run calibrationSelect Derive from measured beat tone->exit to main menu->New measurement -
>”Y”->Select 1KHz as beat-tone (range from 1Hz to 50KHz), input the beat tone signals to the R and L input of the 11848 interface->Proceed->get detector constant
Then change connection back and measure PN
Next time, go to calibration->use current detector constant
Measurement Pay attention to the right and left
channel power level For frequency 1.2 G to 18GL +7->+10dBmR 0->+10dBmKeep R channel close to 10dBm, the
higher R signal, the lower noise floor
Measurement System
Noise Figure Meter-8970BNoise Figure Meter-8970B
CW Generator-8673GCW Generator-8673GOutput power-8dBmOutput power-8dBm
Test Set-8971BTest Set-8971BWorking Mode:SSB3Working Mode:SSB3
From 4-18GHzFrom 4-18GHzDown Convert to Down Convert to
450MHz450MHzSingle Side Band NoiseSingle Side Band Noise
Noise Source DriverNoise Source Driver
Noise Source - 346CNoise Source - 346C
Noise InputNoise InputLO Signal InputLO Signal Input
Single MMIC MeasurementBias For MMICBias For MMICMicrostrip ProbeMicrostrip Probe
Noise OutputNoise OutputNoise InputNoise Input
MMICMMIC
Combiner MeasurementBias For MMICsBias For MMICs
Noise Source Driver InputNoise Source Driver Input
Noise OutputNoise Output
Noise InputNoise Input
Noise SourceNoise Source
Power CombinerPower Combiner
Heat SinkHeat Sink
Measurement Theory
T1 T2 Noise Temperature-TNoise Temperature-T
OutputOutput
Noise PowerNoise Power
NoNo
N1
N2
Na
GdN
dT 0
The Noise Figure Meter output noise at two different noise temperature
Get the G and Na from the measurement
Calibrate to eliminate the affect of the loss of the cable and connectors