Fast Multiharmonic Active Load–Pull System With Waveform Measurement Capabilities

A novel fast multiharmonic active load-pull system is presented, which allows for the acquisition of the complete voltage and current waveforms. The system is capable of measuring multiple different load impedance or input power states within a short time instance (typically 180 states within 20 ms). It also facilitates high-power capability (up to 100 W) and high-frequency operation (up to 50 GHz). Furthermore, the dynamic range at the higher order harmonics is significantly improved by introducing an equalizer in cascade with the wideband harmonic samplers. A new algorithm for presenting the wanted load impedance to the device-under-test is also proposed. The method allows for simultaneous optimization on multiple harmonics, converging within five iterations. This method is applicable to all open loop active load-pull systems and could significantly reduce the number of iterations, hence reducing the measurement time. This paper provides a detailed description of the measurement system, including on-wafer verification measurements.

[1]  J.M. Nebus,et al.  A novel computerized multiharmonic active load-pull system for the optimization of high efficiency operating classes in power transistors , 1995, Proceedings of 1995 IEEE MTT-S International Microwave Symposium.

[2]  Gary R. Simpson,et al.  Importance of 2nd Harmonic Tuning for Power Amplifier Design , 1996, 48th ARFTG Conference Digest.

[3]  P. Roblin,et al.  Pulsed Active Load–Pull Measurements for the Design of High-Efficiency Class-B RF Power Amplifiers With GaN HEMTs , 2009, IEEE Transactions on Microwave Theory and Techniques.

[4]  A. Ferrero,et al.  A novel methodology for fast harmonic-load control with a passive tuner and an active loop , 2010, 2010 IEEE MTT-S International Microwave Symposium.

[5]  S. C. Cripps,et al.  RF Power Amplifiers for Wireless Communications , 1999 .

[6]  Fadhel M. Ghannouchi,et al.  A PC controlled fully automatic active load-pull measurement system using a pseudo-gradient algorithm , 1995, Proceedings of 1995 IEEE Instrumentation and Measurement Technology Conference - IMTC '95.

[7]  Mattias Thorsell,et al.  Large-signal waveform acquisition of pulsed signals , 2011, 2011 41st European Microwave Conference.

[8]  P. Roblin,et al.  New Ultra-fast Real-time Active Load-pull Measurements for High Speed RF Power Amplifier Design , 2007, 2007 IEEE/MTT-S International Microwave Symposium.

[9]  Marco Spirito,et al.  A mixed-signal approach for high-speed fully controlled multidimensional load-pull parameters sweep , 2009, 2009 73rd ARFTG Microwave Measurement Conference.

[10]  M Thorsell,et al.  Electrothermal Access Resistance Model for GaN-Based HEMTs , 2011, IEEE Transactions on Electron Devices.

[11]  Scott A. Harris,et al.  Active simultaneous harmonic source and load pull assisted by local polyharmonic distortion models , 2010, 2010 IEEE MTT-S International Microwave Symposium.

[12]  S. Perlow,et al.  Automatic Load Contour Mapping for Microwave Power Transistors , 1974 .

[13]  J. Verspecht,et al.  An improved coupling method for time domain load-pull measurements , 2005, 2005 European Microwave Conference.

[14]  Lester F. Eastman,et al.  Microwave power limits of AlGaN/GaN HEMTs under pulsed-bias conditions , 2003 .

[15]  C. Weitzel,et al.  RF power amplifiers for wireless communications , 2002, 24th Annual Technical Digest Gallium Arsenide Integrated Circuit (GaAs IC) Symposiu.

[16]  J. Verspecht,et al.  Large-signal network analysis , 2005, IEEE Microwave Magazine.

[17]  N. Rorsman,et al.  An AlGaN/GaN HEMT-Based Microstrip MMIC Process for Advanced Transceiver Design , 2008, IEEE Transactions on Microwave Theory and Techniques.

[18]  N CORPORATIO,et al.  Active Harmonic Load-Pull With Realistic Wideband Communications Signals , 2010 .

[19]  J. Lees,et al.  An Accurate Calibrate-Able Multiharmonic Active Load–Pull System Based on the Envelope Load–Pull Concept , 2010, IEEE Transactions on Microwave Theory and Techniques.

[20]  Christian Fager,et al.  Characterization setup for device level dynamic load modulation measurements , 2009, 2009 IEEE MTT-S International Microwave Symposium Digest.

[21]  Yves Rolain,et al.  Comparison of calibrated S-parameters measured under CW and Pulsed RF excitation with a NonLinear Vectorial Network Analyzer , 2000, 55th ARFTG Conference Digest.

[22]  Y. Takayama.  A New Load-Pull Characterization Method for Microwave Power Transistors , 1976 .

[23]  Andrea Ferrero,et al.  Recent Advances in Real-Time Load-Pull Systems , 2008, IEEE Transactions on Instrumentation and Measurement.