Semiconductors / Integrated Circuits

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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A Voltage-controlled PIN Diode Attenuator Using an Accurate PIN Diode Model

This article presents a voltage-controlled PIN diode attenuator using an accurate PIN diode model that can precisely simulate the attenuation characteristics. After carefully investigating the problems with conventional PIN diode models, an accurate PI...
PIN diodes have been widely used in a variety of microwave and RF applications, including antenna switches, phase shifters and attenuators. PIN diode attenuators are used extensively in automatic gain control (AGC) and RF leveling applications. Most PIN diode attenuators control the attenuation characteristics through the forward bias current....
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Enterprise Software for RF Device Characterization

In today's competitive marketplace the characterization of RF semiconductor devices for modeling, design, applications and process improvement must be faster, more efficient, and more repeatable and accurate as companies strive to improve their product performance, design productivity and time to market. However, help is on hand with the Wavevue...
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Ultra Linear Bandpass Filters

A new product line of ultra linear bandpass filters has been introduced that utilize patent pending cross coupling to reduce time delay and phase distortion up to 90 percent. The filters typically utilize a 12-section filter with two inductive and two capacitive non-adjacent couplings to equalize and flatten the...
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2003 Connector, Cable and Cable Assembly Survey

This is the first survey of connectors, cables and cable assemblies sponsored by Microwave Journal. We hope to update it annually with increased industry participation.
On December 13, 2002, we sent a questionnaire to 75 companies that provide products and services in this field, with a response deadline of January 11th. We used e-mail rather than the USPS so that we would have feedback that all the questionnaires were received. On January 3, 2003,...
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Precision Test Cable Assemblies to 40 GHz

The Accu-Test™ products are a family of precision cable assemblies that are designed for use in the DC to 40 GHz frequency range, intended to facilitate accurate measurements and exhibit low loss characteristics at a competitive price for precision test and measurement applications. The family is currently comprised of...
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Memory Effect Reduction for LDMOS Bias Circuits

Memory effects have taken a very important role in today's design of base station power amplifiers. For example, they are responsible for limiting the cancellation when pre-distortion is applied to a power amplifier system.1 This study show...
Electrical memory effects are defined as changes in amplitude and phase of distortion components caused by modulation frequency. There are several ways of measuring memory effects. One of the most common is to plot the phase and amplitude of the distortion parameters with respect to the tone spacing in...
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