Active Harmonic Load-Pull With Realistic Wideband Communications Signals

A new wideband open-loop active harmonic load-pull measurement approach is presented. The proposed method is based on wideband data-acquisition and wideband signal-injection of the incident and device generated power waves at the frequencies of interest. The system provides full, user defined, in-band control of the source and load reflection coefficients presented to the device-under-test at baseband, fundamental and harmonic frequencies. The system capability to completely eliminate electrical delay allows to mimic realistic matching networks using their measured or simulated frequency response. This feature enables active devices to be evaluated for their actual in-circuit behavior, even on wafer. Moreover the proposed setup provides the unique feature of handling realistic wideband communication signals like multicarrier wideband code division multiple access (W-CDMA), making the setup perfectly suited for studying device performance in terms of efficiency, linearity and memory effects. In this work we describe the hardware and signal conditioning of the proposed setup. The high dynamic range, bandwidth and measurement speed of the system, together with its capability to engineer the large-signal operation of an active device, are demonstrated by measuring the improved RF performance of a multicarrier W-CDMA driven laterally diffused metal-oxide-semiconductor device when the electrical delay in the setup is canceled.