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This paper presents novel nonlinear vector network analyzer (NVNA)-based techniques for characterizing the harmonic and intermodulation nonlinearity of dual-band radio frequency (RF) power amplifiers (PAs). On the one hand, a wideband Schroeder-phase multisine is used to drive a step recovery diode comb generator, so that a novel multiharmonic-band NVNA phase reference on a dense spectral grid is obtained. On the other hand, a novel phase calibration approach is developed to synchronize the NVNA multiband measurements. To validate the NVNA testbed with novel techniques, an RF PA under two typical kinds of dual-band multisine stimulus is tested, where the NVNA measurement is compared with that of an oscilloscope. This paper can be easily adapted for various multiband conditions. [ABSTRACT FROM PUBLISHER]

This paper presents a novel realization of nonlinear vector network analyzer (NVNA) test-bed with a new phase calibration technique, in order to characterize the multiharmonic intermodulation nonlinearity of a radio frequency (RF) power amplifier (PA) under a large-signal modulated input. The NVNA test-bed uses a step recovery diode comb generator as the phase reference, which is driven by a pulsed-RF signal with a high duty cycle of over 99%. Hence all the multiharmonic intermodulation tones of interest can be measured at once. A multisine phase standard provided by a vector signal analyzer is used to calibrate the intermodulation tones at each harmonic on a dense spectral grid. Two harmonic phase standards with different fundamental frequencies are used to synchronize the phase calibration results at different harmonics. The validity of this paper is verified by comparing NVNA measurements with oscilloscope measurements of the same PA under test. This paper can be used to inspect the nonlinearity of RF amplifiers under large-signal modulated excitations in both the frequency and time domains. [ABSTRACT FROM AUTHOR]

The step-recovery-diode-based impulse generator is a classical picosecond-level impulse-formation technique, whose strong harmonic nonlinearity under sinusoidal stimulus is widely utilized as the phase reference of the nonlinear vector network analyzer (VNA) (NVNA) and large-signal network analyzer for wideband measurements. This paper further exploits its intermodulation nonlinearity under multitone stimulus and proposes a new approach, rather than the traditional “harmonic” way, of the NVNA phase reference for future polyharmonic intermodulation measurements. Experimental results show that this method can provide plentiful intermodulation components around each harmonic available and is stable for NVNA use, with the advantages of flexible local frequency-resolution setup from tens of megahertz to less than hundreds of hertz. [ABSTRACT FROM PUBLISHER]

This paper studies the systematic uncertainties of nonlinear vector network analyzer (NVNA) measurements and presents a covariance-matrix-based method to analyze the uncertainty propagation from calibration standards and hardware to error model terms and effective measurements. Analytic deductions of the Jacobians for frequency-domain quantities are proposed, dealing with the complex NVNA measurements and calibration functions. An NVNA two-port-calibration uncertainty is put forward as a new kind of systematic uncertainty consideration for this vector-correction-based instrument. Experiments on our prototype NVNA show the necessity of using covariance-matrix-based uncertainty analysis, particularly for polyharmonic measurements, and reveal some features of NVNA uncertainty analysis due to the calibration techniques. [ABSTRACT FROM PUBLISHER]