AWR Corporation

About: AWR Corporation is a based out in . It is known for research contribution in the topics: Distortion & Frequency response. The organization has 27 authors who have published 23 publications receiving 664 citations.

A comparative overview of microwave and wireless power-amplifier behavioral modeling approaches

Abstract: This paper presents a comparative overview of the most important approaches presented to address the behavioral modeling of microwave and wireless power amplifiers (PAs). Starting from a theoretical framework of recursive and nonrecursive nonlinear filters, it proposes a classification of the various PA behavioral models, discussing their abilities to represent the different effects observed in practical circuits. Using that formal procedure, one explains how it was possible to integrate a wide range of behavioral modeling activities and to show that some of them, which at first glance seemed to be quite different, are, indeed, identical in their modeling capabilities.

A fast and accurate Rayleigh fading simulator

Abstract: This paper presents a simulator that efficiently generates correlated complex Gaussian variates with a power spectral density as described by Jakes (Jakes, Jr., 1974). The simulator consists of a fixed IIR filter followed by a variable polyphase interpolator, to accommodate different Doppler rates. The IIR filter was designed using an iterative optimization technique known as the ellipsoid algorithm, following an optimization technique that is more generally applicable and can be used to approximate any given magnitude frequency response. Software to implement both the IIR filter design technique and the complex Rayleigh fading simulator itself are available at the author's Website or by email.

A new circuit augmentation method for modeling of interconnects and passive components

Abstract: This paper presents a new methodology for automated broadband model generation from S-parameter data for interconnects and passive components. The new methodology is based on augmenting an existing equivalent circuit model with a macromodel (black-box) network described by rational functions while simultaneously perturbing the equivalent circuit component values. The macromodel network is determined using standard least-squares or vector-fitting approaches. The perturbation of the equivalent circuit parameter values is achieved during the macromodel generation by means of global optimization based on intelligent search algorithms. The new approach is demonstrated on several two-port test example structures including a broadband probe tip structure and a CMOS spiral inductor.

Wideband diversity in multipath channels with nonuniform power dispersion profiles

Abstract: The focus of this paper is to derive the symbol error probability (SEP) of a Rake receiver with a limited number of fingers that track the strongest multipath components in a frequency-selective Rayleigh fading channel. We develop an analytical framework that allows the computation of the SEP for nonuniform power dispersion profiles (PDPs) and spreading bandwidth. By transforming the physical Rake receiver with correlated ordered paths into the domain of a 'virtual Rake" receiver with conditionally independent virtual paths, analytical expressions for the SEP are derived in terms of the spreading bandwidth, the channel profile, and the number of combined paths. We show how our analytical results can be used to predict the performance of various Rake architectures in environments with nonuniform PDPs using for example, the channel models defined for the next generation wireless standards. Furthermore, we validate our methodology by comparison to data obtained from channel measurements, showing good agreement with our analytically derived results.

Zero index metamaterials with checkerboard structure

Abstract: A metamaterial design is presented with an effectively zero index of refraction, which utilises Drude-type material blocks arranged in a checkerboard pattern within a nondispersive dielectric host. An averaging effect over constituent materials of the checkerboard structure yields an effective permittivity that approaches zero. This results in a metamaterial with a zero index of refraction and a high intrinsic impedance. A design example and the associated effective medium parameters are provided.