EDGE Modulation — How Linearization Improves Amplifier Performance 

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 

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....

Adaptive DC power management for HBT PAs in CDMA handsets 

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

Noise and ACPR correlation in CDMA power amplifiers 

[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 

[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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