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—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(More)
Support vector machine (SVM), built on statistical learning theory (SLT), was proposed by Vapnik in 1995. Being based on structural risk minimization (SRM) principle, SVM has a better generalization performance in comparison to those traditional methods on learning problems. Originally, SVM was used to construct classifiers for pattern recognition, and(More)
Advantages of wireless sensor networks have germinated many new applications in both military and civil domains. Many researchers are engaged in designing new protocols for sensor networks where energy awareness is an essential consideration. We identify the trends that wireless sensor networks should be maneuverable by user from Internet and propose a new(More)
Spectrum sensing plays an important role in cognitive radios, of which a feasible method that fulfills both detection agility and users' mobility requirement remains unknown. In this paper, we identify the trend that mobility of cognitive users should be considered in near future and propose using ultra wide band (UWB) positioning system to fulfil mobility(More)
—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(More)
This paper presents an extended behavioral model for the modeling of microwave amplifiers, namely harmonics dynamic X-parameters. This model aims at providing a powerful analysis capability for the prediction of fundamental and harmonic large-signal responses with long-term memory effects for the power amplifier. Several major problems faced by current(More)
SVC (scalable video coding) technique is such a new technique that just be proposed to overcome the shortage and insufficiency in the conventional unscalable coding system. At present, the algorithm based on DCT can not combine spatial scalability and other scalabilities together because it could not provide spatial localization property. So In recent(More)
This paper presents a quadrature direct digital frequency synthesizer (QDDFS) with super high memory compression ratio and analyzes its design principle theoretically. Its parameters have also been optimized. Trigonometric approximation and linear approach are combined coherently in order to reduce the size of the ROM (1856 bit). The compression ratio for(More)
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(More)
In this paper, analytical expressions of the input reflection coefficient at the source and the load ports of a two-port active microwave component are proposed. It utilizes the load-dependent X-parameters in the development of these expressions. In contrast to the classical small-signal S-parameters based approach, the cross frequency conversions and(More)