Multitone IMD offers clearer picture of MCPA performance 

Sep 1, 2003, By Marta Iglesias

Characterizing distortion is essential when evaluating multicarrier power amplifier (MCPA) performance. Traditional two-tone tests for intermodulation distortion (IMD) or single-carrier adjacent channel power ratio (ACPR) measurements are not sufficient to evaluate MCPAs. These amplifiers must instead be evaluated using multiple carriers as the stimulus, which more realistically simulate conditions the amplifiers will encounter in service. As an alternative to multiple carriers, multiple tones w...

Introduction to GSM and GSM Mobile RF Transceiver Derivation 

Jun 1, 2003, By Paul Kimuli

The GSM system works properly only when its component parts operate within precise limits. Learn the key measurements required for testing GSM transceivers....

Fundamentals of Digital Quadrature Modulation 

Feb 1, 2003, By Ken Gentile

How a formerly analog-only application, the quadrature modulator, is finding a home in modern digital CMOS fabrication techniques...

Microwave PA Thermal Design for SATCOM Systems 

Jan 1, 2003, By Stephen D. Turner, and Ahmed M. Zaghlol

For many years, solid state power amplifiers and traveling wave tube amplifiers have been in competition in communication services. This is particularly so in satellite communication systems. Currently, the highest RF output power achievable from microwave transistors is 60 W at 6 GHz and 20 W at 14 GHz. Not only is the DC to RF efficiency a concern, but the RF combining efficiency is also critical to the success of a solid state power amplifier....

Characterizing Phase Noise 

Jan 1, 2003, By Mini-Circuits Inc.

A tutorial for the novice RF engineer on how to characterize phase noise....

EDGE Modulation — How Linearization Improves Amplifier Performance 

Oct 1, 2002, By T. J. Fergus

Historically, the global system for mobile Communications was intended to make power amplifier design simpler. With the introduction of high order modulation schemes for 2.5 and 3G, the design challenges presented to the PA have increased significantly. This article describes the design and implementation of a polar loop to improve the efficiency of a gallium-arsenide field effect transistor (GaAs FET) power operating at 1.91 GHz....

Designing High Efficiency Overdriven and Saturated Power Amplifiers 

Oct 1, 2002, By Francisco Javier Ortega-González, Alberto Asensio-López, Alberto Martín-Consuegra

It is common knowledge that efficiency is a major issue with the design of any transmitter. The benefits of high efficiency include power consumption, low power derating and high reliability, among others. In order to improve efficiency several specific amplification classes, such as class E¹ have been described in classical literature. Nevertheless, the strict conditions required by high efficiency amplification techniques are difficult to achieved at high frequencies....

Designing LC Wilkinson power splitters 

Aug 1, 2002, By Fernando Noriega, Pedro J. González

Wilkinson power splitters are common transmission path elements. Designers can implement them more effectively by knowing their nuances....

Indoor wireless networks: issues and answers 

Apr 1, 2002, By Tom Snyder, John Catlin

Implementing reliable indoor wireless voice and data networks is difficult at best. To get optimum quality of service, know what you’re up against before the system goes in....

Who invented radio? 

Feb 1, 2002

Who invented radio? 

Feb 1, 2002, By Don Bishop Editorial Director

Who do you think invented radio? Harold Kinley, a contributing editor to our Wireless Telecommunications Group of magazines (of which RF Design is a member)...

Adaptive DC power management for HBT PAs in CDMA handsets 

Feb 1, 2002, By James A. Roche, Richard M. Healy, Gary Hau, Ph.D., and Sara A. Caron

In today's wireless handset market, extending battery life for increased standby and talk time continues to be a paramount goal. Because battery technology...

Matched Filtering and Timing Recovery in Digital Receivers 

Sep 1, 2001, By Louis Litwin

A practical look at methods for signal detection and symbol synchronization....

Noise and ACPR correlation in CDMA power amplifiers 

May 1, 2001, By Oleksandr Gorbachov, Yu Cheng and Jason S. W. Chen

[For a copy of this article in PDF format, which displays figures and equations, click here. Requires Adobe Acrobat Reader, free download.] The issue...

Mounting high-power flanged RF devices to multi-layer PCBs 

Mar 1, 2001, By Kedaar Kale and Adam Loveridge

[For a copy of this article in PDF format, which displays figures and equations, click here. Requires Adobe Acrobat Reader, free download.] Conventional...

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