1 / 32

Andrea Ferrero Dipartimento di Elettronica Politecnico di Torino, Italy

Overview of modern load-pull and other non-linear measurement systems ARFTG Nonlinear Measurements Workshop San Diego, November 2001. Andrea Ferrero Dipartimento di Elettronica Politecnico di Torino, Italy. Basics of load-pull. Definitions. Load-pull

skah
Download Presentation

Andrea Ferrero Dipartimento di Elettronica Politecnico di Torino, Italy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Overview of modern load-pull and other non-linear measurement systemsARFTG Nonlinear Measurements WorkshopSan Diego, November 2001 Andrea FerreroDipartimento di ElettronicaPolitecnico di Torino, Italy

  2. Basics of load-pull Definitions • Load-pull • Controlling the loading condition at the output port • Source-pull • Controlling the loading condition at the input port • Fundamental load-pull • Controlling the loading/source condition at the fundamental frequency • Harmonic load-pull • Controlling the loading condition at one or more harmonic frequencies ARFTG –2001 – San Diego

  3. Basics of load-pull Example of load-pull data Output power [dBm] @ 1dB gain compression Power Added Efficiency (PAE) [%] @ 2dB gain compression ARFTG –2001 – San Diego

  4. Basics of load-pull Measurement systems • Power meter or scalar analyzer-based • only scalar information on DUT performances • economic • Vector receiver (ANA, 6-port) • vectorial and more complete informations on DUT performances • high accuracy, thanks to vector calibration • expensive • Time Domain Receiver (MTA-NVNA) • Waveform capabilities • Complexity, high cost ARFTG –2001 – San Diego

  5. and power sensors Passive tuners Power Meter Power Sensor G G Power Sensor S L Passive load-pull systems • Passive loads • Mechanical tuners • Electronic tuners (PIN diode-based) ARFTG –2001 – San Diego

  6. Passive load-pull • Features • Single or double slug tuners • High repeatability of tuner positions • Pre-characterization with a network analyzer • High power handling ARFTG –2001 – San Diego

  7. Passive Load Pull Motors Slab Line DUT TUNERS ARFTG –2001 – San Diego

  8. Passive Limits • Drawback • Load reflection coefficient limited in magnitude by tuner and test-set losses • This is true especially for harmonic tuning • higher frequency • optimum load on the edge of the Smith chart ARFTG –2001 – San Diego

  9. LOSS G LOSS G G L L L PreMatching • Pre-matching • To reach higher gamma while characterizing highly mismatched transistors • Pre-matching networks • Pre-matched tuners • Features • Highest gamma attainable • Difficult pre-calibration (5D space!!) • Harmonic Loading uncontrolled ARFTG –2001 – San Diego

  10. PreMatching ARFTG –2001 – San Diego

  11. VECTOR INFO ACTIVE LOADS NETWORK ANALYZER PORT 2 SWITCHING NETWORK NORMAL VNA CAL DUT Real Time load-pull Vector network analyzer-based system OutputLoad InputLoad ARFTG –2001 – San Diego

  12. Active load Active loop technique ARFTG –2001 – San Diego

  13. Harmonic Load Pull • Controlling the Load/Source condition at harmonic frequencies • Waveshaping techniques at microwave frequencies • Great complexity of the system but potential improvement of the performance ARFTG –2001 – San Diego

  14. G f0 G 2f0 Passive load-pull Passive Harmonic system • A Tuner for each harmonic • Complex • Easy to change frequency • More control of the harmonic load • Harmonic Resonators • Difficult to change frequency • Only Phase control of the load Fundamental Harmonic ARFTG –2001 – San Diego

  15. Harmonic active load-pull Extending the active loop technique Politecnico di Torino System ARFTG –2001 – San Diego

  16. Harmonic active load-pull Extending the active loop technique IRCOM Active Harmonic Load Pull ARFTG –2001 – San Diego

  17. 4 Loops Harmonic system VNA Amplifier Loop Unit Switching Unit Couplers DUT and Probe Maury/Paf Active Harmonic Load Pull ARFTG –2001 – San Diego

  18. VECTORAND TD INFO ACTIVE LOADS MTA TD WAVEFORMS Ref Signal Test Signal SWITCHING NETWORK TD CAL REQUIRED DUT Time domain load-pull Transition Analyzer based system OutputLoad InputLoad ARFTG –2001 – San Diego

  19. Calibration and Verfication • Passive System • Coaxial VNA Measurement of the Tuners for different positions (typically thousands) • De-embedding of external components (probe,cables ..) • Real Time Active System • Standard Measurements directly at the reference plane • Error Model as ordinary S-parameters ARFTG –2001 – San Diego

  20. DUT G G in L 1 2 PwrMeter Short NETWORK ANALYZER Short SWITCHING NETWORK Open Thru Load Line G G t 3 Probe Tip Load-pull Accuracy VNA-based system: calibration • Reference plane definitions ARFTG –2001 – San Diego

  21. Uncertainty Main Contributions to Power Waves Calibration Residual Uncertainty • NWA measurement repeatability (0.1 %) • Uncertainty on power calibration coefficient (input TWTA during calibration: 2%, no TWTA 0.5%) • On-wafer probe position repeatability (0.2%) ARFTG –2001 – San Diego

  22. Passive LP System Main Contributions to Uncertainty • tuner position repeatability • S-parameter measurement uncertainty: • residual NWA calibration uncertainty • NWA repeatability • measured power uncertainty (power meter dynamic range) ARFTG –2001 – San Diego

  23. passive LP: red line • active LP Comparison Passive vs. Active Output Power Standard Uncertainty dBm 0.5 0.4 0.34 0.25 0.17 0.086 ARFTG –2001 – San Diego

  24. Load Pull and PA Design • Classical PA design Information like: • Power Sweep • Optimum Loads • MAP based design • Additional info with Active Real Time System • GammaIn • AM/PM conversion • Harmonic Load condition • Time Domain Info ARFTG –2001 – San Diego

  25. DATA SET EXAMPLE Load Pull and PA Design ARFTG –2001 – San Diego

  26. Power Sweep and more 1dB compression Point Pout=26.29 dBmGain= 9.72dB IM3R= -18.34 dBc IM3L=-18.50dBcEff=48.07 % ARFTG –2001 – San Diego

  27. Load Pull and PA Design COMBINING LP MAP INFORMATION TO OPTIMIZE POWER PERFORMANCES 12dB OUTPUT POWER @ 1 dB GAIN COMPRESSION POWER GAIN@ 1 dB GAIN COMPRESSION 26dBm ARFTG –2001 – San Diego

  28. Load Pull and PA Design COMBINING LP MAP INFORMATION TO OPTIMIZE LINEARITY PERFORMANCES PAE @ 1 dB GAIN COMPRESSION 50% -28dBm C/I 3 LEFT @ POUT = 24 dBm ARFTG –2001 – San Diego

  29. Harmonic Information Harmonic Load Effect on Efficiency Power Added Efficiency (PAE) [%] @ 4 GHz, 2dB gain compression as a function of the second harmonic load value (8 GHz). ARFTG –2001 – San Diego

  30. Time Domain LP Istantaneous Working Point Waveform check ARFTG –2001 – San Diego

  31. Conclusions • Load-pull test set as important tools for: • Power amplifier design • Model Verification • Device optimization • Different possibility available according to • Testing needs • Application needs • Budget ARFTG –2001 – San Diego

  32. Many Thanks to • Dave Hartskeerl - Philips Research Laboratories • Surinder Bali – Maury Microwave ARFTG –2001 – San Diego

More Related