Load Pull with X-Parameters

Transcription

1 Load Pull with X-Parameters A New Paradigm for Modeling and Design Gary Simpson, CTO Maury Microwave March 2009 For a more detailed version of this presentation, go to 1

2 Outline Overview Motivation and Solution A New Paradigm for Modeling and Design Overview of X-Parameters Traditional Large Signal Model vs X-Parameter Model System Setup and Operation Results Quick Demo Summary 2

3 Motivation PA Design is Becoming More Complex Multi-Stage, Doherty, etc More than Just Matching One Device Large Signal Models are Needed Accurate Fast Turn-Around 3

4 Load Pull Prior Art Separate Disciplines Determine Match for a Single Device Verify Large Signal Models X-Parameters at 50 Ohms Good to simulate system with 50 Ohm blocks But Power Devices are far from 50 Ohms Measurement was not Easy 4

5 Solution: Load Pull with X-Parameters Instant Large Signal Model 5

6 Instant Large-Signal Model Maury Load Pull Agilent NVNA SW in PNA-X Run Sweep Plan Save X-Param File Simulate in ADS 6

7 Instant Large Signal Model X-Parameter Component V_DC SRC1 Vdc=8 V Vs_low I_Probe Is_low DC_Feed DC_Feed1 Vs_high I_Probe Is_high DC_Feed DC_Feed2 DC_Block DC_Block1 I_Probe Iload V_DC SRC2 Vdc=-1 V I_Probe P_1Tone Isrc PORT1 Num=1 Z=Z_s P=dbmtow(Pavs) Freq=RFfreq vsrc DC_Block DC_Block2 WJ_FP2189_PHD WJ_FP2189_PHD_1 fundamental_1=_freq1 vload S1P_Eqn S1 S[1,1]=LoadTuner Z[1]=Z0 Industry Breakthrough 7

8 Load Pull with LSNA Time Domain 8

9 NVNA Nonlinear Vector Network Analyzer Superset of LSNA 3-Step Calibration Vector Cal Similar to standard VNA Cal Power Cal Use a power meter Phase Cal Use a comb generator as a Harmonic Phase Reference Measures Time-Domain and X-Parameters X-Parameters are Unique to Agilent NVNA 9

10 X-Parameter Overview X-params are to non-linear devices like S-params to linear devices. linear : S-params In S Out S In non-linear : X-params In In In X Out Out Out X In In In 10 Group/Presentation Title Agilent Restricted

11 S-Parameters VNA measures amplitudes and phases of Linear signals. 11 Group/Presentation Title Agilent Restricted

12 X-Parameters NVNA measures amplitudes and phases of harmonic distortion signals. Phases of distortions can be measured. Group/Presentation Title Agilent Restricted 12

13 X-Parameter Summary Non-Linear Generalization of S-Parameters S-Parameters are special case where distortion = 0 Frequency Grid Includes: All Harmonics All Intermods Baseband Parameters at Each Freq Parameters Between Each Freq Combination Data covers one Large Signal Operating Point 13

14 Traditional Large-Signal Model Use Small Signal and DC measurements Fit Model Parameters to Data Time-Consuming Accuracy Limited in Some Regions of Operation Technology Dependent Model is Extrapolated to Large Signal Load Pull is Accuracy Reference Load Pull is Measured at Actual Large Signal 14

15 X-Parameter Large Signal Model Based on Large Signal Measurements of X-Parameter Data Includes all Parasitics up to Reference Plane Technology Independent Hides Design Details of Device Load Dependent Data for PA Design 15

16 X-Parameter Large Signal Model Over Entire Smith Chart In the Past, the X-Parameter model was only used at or near 50 Ohms New: Load-Dependent X-Parameters Co-Developed by Maury and Agilent New Paradigm for Modeling and Design 16

17 X-Parameter Large Signal Model Over Entire Smith Chart Create Instantly from Load Pull Data Very Accurate Based on Large Signal Load Pull Measurement Region of Validity Sweep Plan Range Selected by User Sweep Gamma, Power, Bias, Freq, Etc. Simulate Complex PA Circuits 17

18 What is Load Pull? Measurement vs. Impedance Stimulus and Measurement TUNER DUT TUNER Γ source Γ Load 18

19 Load Pull + X-Parameter Setup Bias System PNA-X NVNA + Maury Software Exclusive to Maury And Agilent Maury Tuner DUT Maury Tuner 19

20 Load Pull to Circuit Simulation Sequence 1. Calibrate System, including Tuners 2. Calibrate NVNA at DUT Plane 3. Connect the DUT and Measure Sweep Plan Sweep Gamma, Power, Bias, Freq, Etc. 4. Drag and Drop X-Param File into ADS 5. Simulate Circuit 20

21 System Operation - Measurement NVNA controlled by Maury ATS software. X-Params option in parameter selection dialog Fully automated measurement Page NVNA + Load Pull Instant Large Signal Model December 11, 2008

22 System Operation - Measurement Sweep Plan Up to 7 Variables Fully Automated Measurement Measure over Full Range of Device Operation 22

23 System Operation - Simulation Copy file into ADS project X-Parameter Design Kit does the rest! Page NVNA + Load Pull Instant Large Signal Model December 11, 2008

24 Instant Large Signal Model X-Parameter Component V_DC SRC1 Vdc=8 V Vs_low I_Probe Is_low DC_Feed DC_Feed1 Vs_high I_Probe Is_high DC_Feed DC_Feed2 DC_Block DC_Block1 I_Probe Iload V_DC SRC2 Vdc=-1 V I_Probe P_1Tone Isrc PORT1 Num=1 Z=Z_s P=dbmtow(Pavs) Freq=RFfreq vsrc DC_Block DC_Block2 WJ_FP2189_PHD WJ_FP2189_PHD_1 fundamental_1=_freq1 vload S1P_Eqn S1 S[1,1]=LoadTuner Z[1]=Z0 Industry Breakthrough 24

25 Results Packaged FET Extremely Accurate Agreement Pout PAE Blue Simulated, Red - Measured 25

26 Results Packaged FET Measured and Simulated Voltage and Current Waveforms SimulatedVoltage MeasuredVoltage SimulatedCurrent MeasuredCurrent time, nsec Measured and Simulated Voltage and Current Waveforms SimulatedVoltage MeasuredVoltage Measured and Simulated Voltage and Current Waveforms SimulatedCurrent MeasuredCurrent SimulatedVoltage MeasuredVoltage time, nsec SimulatedCurrent MeasuredCurrent time, nsec Page NVNA + Load Pull Instant Large Signal Model December 11, 2008

27 Measured vs. Simulated Extremely Accurate Current Voltage 27

28 PAE and Pout vs. Harmonic Loads Second Harmonic Load ( ) ( ) PAE (red) and Pout (blue) Third Harmonic Load 0.1% contour step for PAE, 0.01dBm contour step for delivered power Page NVNA + Load Pull Instant Large Signal Model December 11, 2008

29 Demo Quick ADS Demonstration Drag and Dropping X-Parameter File into Schematic Simulate, See Results 29

30 Summary X-Parameters = Non-Linear Data Instant Large Signal Model Load Pull + NVNA + ADS Load Pull Produces X-Parameter File Drag and Drop as Large Signal Model Very Effective for Complex PA Design 30

31 Summary Load Pull with X-Parameters: A Fast and Accurate Approach to Large-Signal Modeling and Simulation New Paradigm for Modeling and Design Industry Breakthrough 31

32 Complex PA Design Solution: Load Pull with X-Parameters Instant Large Signal Model 32

33 References [1] J. Verspecht and D. E. Root, Poly-Harmonic Distortion Modeling, in IEEE Microwave Theory and Techniques Microwave Magazine, June, [2] J. Verspecht, D. Gunyan, J. Horn, J. Xu, A. Cognata, and D.E. Root, Multi-tone, Multi- Port, and Dynamic Memory Enhancements to PHD Nonlinear Behavioral Models from Large-Signal Measurements and Simulations, 2007 IEEE MTT-S Int. Microwave Symp. Dig., Honolulu, HI, USA, June [3] J. Horn, D. Gunyan, L. Betts, C. Gillease, J. Verspecht, and D. E. Root, Measurement- Based Large-Signal Simulation of Active Components from Automated Nonlinear Vector Network Analyzer Data via X-Parameters, in 2008 IEEE COMCAS Conference, Tel Aviv, Israel, March, 2008 [4] D. E. Root, J. Verspecht, D. Sharrit, J. Wood, and A. Cognata, Broad-Band, Poly- Harmonic Distortion (PHD) Behavioral Models from Fast Automated Simulations and Large-Signal Vectorial Network Measurements, IEEE Transactions on Microwave Theory and Techniques Vol. 53. No. 11, November, 2005 pp [5] G. Simpson, J. Horn, D. Gunyan, and D. E. Root, Load-Pull + NVNA = Enhanced X- Parameters for PA Designs with High Mismatch and Technology-Independent Large- Signal Device Models, 72nd ARFTG Conference, Dec 9-12, 2008 Page X-Parameters: Measurement, Modeling, and Simulation January 21, 2008