The generation of RF/microwave power is required not only in wireless communications, but also applications such as jamming, imaging, RF heating, and miniature dc/dc converters. Each application has its own unique requirements for frequency, bandwidth, load, power, efficiency, linearity, cost. generated by a wide variety techniques, implementations, active devices. Power amplifiers are incorporated into transmitters similarly architectures, including linear, Kalm, envelope tracking,...

A novel load-pull method for envelope-termination characterization is presented. The enables the source and load envelope terminations to be easily evaluated further optimize linearity/efficiency tradeoff of RF/microwave power transistors used in digital wireless communication systems with time-varying envelopes. Results are presented a 53 mm low-voltage LDMOS transistor at 850 MHz. It shown that optimal termination may general complex, contrast commonly held belief must approximately zero....

Power amplifier (PA) efficiency for wireless communication systems is universally calculated at maximum output power. While this method has evolved into the de-facto figure-of-merit, it ignores system effect on average power, and cannot in general provide an accurate estimate of PA impact phone talk-time. A more meaningful its long-term mean based statistics power a typical environment. This new characterization provides improved talk-time by including variation not summary given, with two...

The integration of nonlinear current-voltage selectors and bi-stable memristors is a paramount step for reliable operation crossbar arrays. In this paper, the self-aligned assembly single nanometer-scale device that contains both selector memristor presented. two components (i.e., memristor) are vertically assembled via fabrication process combined with electroforming. designing device, niobium oxide tantalum chosen as materials memristor, respectively. formation visualized by exploiting...

Adoption of digital modulation for many wireless communication systems has resulted in significant performance improvements over based on analog modulation. Concomitant with this have been changes methods characterizing and simulating system performance, particularly respect to amplifier linearity. Digitally modulated signals are best represented by a power spectral density. In contrast, analog-modulated adequately discrete spectra. Consequently, the common spectra nonlinear microwave...

A comparison of nonlinear analysis methods for simulation power amplifier adjacent-channel ratio is presented. Adjacent-channel the linearity figure-of-merit digital wireless communication systems employing non-constant envelope modulation techniques, such as OQPSK and /spl pi//4-QPSK. Tradeoffs in performance each method are discussed. Using TIA IS-95 IS-54 standards, measured simulated results a single-stage

The peak-to-average ratio (PAR) of a signal is commonly used for estimating the backoff required an radio-frequency/microwave power amplifier to exhibit acceptable intermodulation distortion. In this paper, it shown that PAR inaccurate metric predicting and can lead improper choices modulation with respect linearity-efficiency tradeoff. A specific case presented, based on IS-94 code-division multiple-access communication (CDMA) reverse-link IS-95 CDMA forward-link wireless standards. Using...

Self-assembled niobium dioxide (NbO2) thin-film selectors self-aligned to tantalum (TaO2) memristive memory cells are studied by a multi-physics transient solution of the heat equation coupled nonlinear current continuity equation. While compact model can resolve quasi-static bulk negative differential resistance (NDR), self-consistent transport formulation provides non-equilibrium picture NbO2-TaO2 selector-memristor operation ab initio. By employing drift-diffusion approximation, finite...

A large-signal fully automated load-pull system for characterization of adjacent-channel power /spl pi//4-DQPSK-based digital wireless communication systems is described. It demonstrated that the commonly held beliefs North American follows a third-order process and Japanese fifth-order are in general not true. Instead, it shown composite third- nonlinearities, relative contributions each being load impedance device dependent. simplified series analysis coupled with spectral decomposition...

Large-signal adjacent-channel power ratio load-pull contours of a GaAs MESFET and HEMT excited by π4-DQPSK modulation are demonstrated for the first time using an automated system. It is shown that in general there only weak relationship between two-tone third-order intermodulation (Japanese) Personal Digital Cellular standard. The both load impedance device technology dependent insofar as linearity characterization cannot generally be used to optimize power. system presented here independent.

Transistors used for cellular and PCS infrastructure applications are required to amplify signals with a peak-average ratio that can exceed 13 dB, resulting in PEP approaching 1 kW. This requirement is consequence of simultaneous amplification multiple digitally modulated carriers time-varying envelope, requires load resistance the neighborhood 0.3 Ω Present load-pull technology, based on mechanical tuners, limited approximately at frequencies, which render these systems incapable...

Transient electroformation simulation of niobium oxide selectors, self-aligned to tantalum dioxide memristor structures, is described by a computational solution the mass transport equation self-consistently coupled heat and electronic charge equations. Augmentation an electrothermal drift-diffusion formulation thermally activated field-enhanced term describes transient evolution ab initio electric potential, temperature, carrier density model our oxide-tantalum selector-memristor structure....

Memristive devices are two-terminal electrical switches with resistance that depends on a state variable equivalent to charge. In practice, multiple memristive arranged into crossbar array form such components as memory and logic. For reliable operation of the array, current sneak paths need be eliminated by combining highly nonlinear component, known selector, device. This ensures explicit selection an intended device without disturbing states surrounding devices. However, integrating...

A phase field method self-consistently coupled to continuum heat transport and charge conservation is used simulate conducting filament dynamical evolution nanostructure of electroformed resistive switching thin films. Our does not require a pre-defined idealized filament, as previous methods do, instead treating its stochastic diffuse interface problem subject variational principle. simulation results agree well with available experimental observations, correctly reproducing exhibited by variety