Industry News

The Commercial Market

The Commercial Market IEEE 802.20 Will Set Data Rates Above 1 Mbps for Mobile Users Mobile broadband wireless access (MBWA) for computers, personal digital assistants and other battery-powered devices is to take a major step forward. The next two years will see a standard developed at the IEEE to...
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The Book End

Software Radio, A Modern Approach to Radio Engineering Jeffrey H. Reed Prentice Hall PTR 565 pages; $92 ISBN: 0-13-081158-0 Software radios represent a major change in the design approach for radios in which a large portion of the functionality is implemented through programmable signal processing devices, giving the radio...
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High Performance Comb Generator Multipliers

A new line of comb generator multiplier products is featured
A comb generator is a device with outputs that are multiple harmonics of an input signal. The output spectral tone lines are uniformly spaced at integer multiples of the input reference. A spectrum analyzer display of the output looks much like the teeth of a comb, which is how...
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An Adaptive Feedforward Amplifier for WCDMA Base Stations Using Imperfect Signal Cancellation

This article describes a new adaptive feedforward amplifier for a WCDMA system using an imperfect signal cancellation. Due to the complicated signal statistics, the distortion generated by the error amplifier is significantly reduced by an imperfect si...
As wireless systems evolve from second- to third- or fourth-generation, the linearity, efficiency and bandwidth requirements for power amplifiers become more stringent. Many techniques, including feedforward, envelope feedback and manifold types of predistorters, have been employed to effectively satisfy these performance requirements and to reduce the production costs for...
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Design of a Predistorter Controlling Individual Orders of Intermodulation Using a New Harmonic Generator

A new type of predistortion linearizer is presented which uses individual orders of intermodulation to linearize a power amplifier. This new predistortion linearizer has two harmonic generators, each consisting of four diodes biased independently. Sinc...
In multi-carrier power amplifiers, a feedforward technique is generally adopted due to its extremely linear and broadband characteristics. 1 However, the feedforward technique requires large circuits and is expensive because of its complexity. It uses two cancellation paths, and delay lines are inserted in each path to adjust the...
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A Novel Adaptive Feedforward Amplifier Using an Analog Controller

A novel adaptive design for a feedforward amplifier linearizer with an analog controller is proposed in this article. Compared with previous adaptive linearizing methods, this new design does not require any pilot signal or intentional signal distortio...
For the third-generation (3G) mobile radio standards, a very high linearity transmitter that can support high crest factor signals is necessary. High linearity and high efficiency are critical issues in amplifier design. In fact, as the power amplifier operates close to the saturation region where both high efficiency and...
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