Conventional outphasing power amplifier systems require both an RF carrier input and a separate baseband input to synthesize a modulated RF output. This work presents an RF-input / RF-output outphasing power amplifier that directly amplifies a modulated RF input, eliminating the need for multiple costly IQ modulators and baseband signal component separation as in previous outphasing systems. An...

Class-E amplifier has the potential to deliver high efficiency required for the next generation wireless systems. In this journal, we discuss a novel load pull analysis technique to characterize the efficiency performance of Class-E amplifier in an outphasing power combining scheme. Class-E amplifier is not an ideal current or voltage source as is required for the traditional analysis of outpha...

A novel load pull methodology to characterize the performance of class-E outphasing power amplifiers is presented. The traditional analysis of the outphasing topology cannot be applied when classE amplifiers are used because these amplifiers do not behave as an ideal current or voltage source. Unlike most other amplifier classes, class-E amplifiers require a phase modulated input signal with co...

In this paper an outphasing modulation control method suitable for line regulation of very high frequency resonant converters is described. The pros and cons of several control methods suitable for very high frequency resonant converters are described and compared to outphasing modulation. Then the modulation technique is described and the design equations given. Finally a design example is giv...

H igh efficiency linear amplification is of great interest in modern communication systems as it increases talk time, decreases power consumption , decreases heat dissipation, and improves reliability. The efficiency of linear power amplifiers (PAs) is highest at the peak output power (PEP) and decreases significantly for low amplitudes, as shown in Figure 1. Signals with time-varying amplitude...

Outphasing transmitters have been explored to study the trade-off between linearity and efficiency. The outphasing technique enhances efficiency by operating two amplifiers at lower output amplitudes, using two constant envelope signals. Their major drawback is the inherent sensitivity to gain and phase imbalances between the two amplifier branches. Another important issue is related to the deg...

Wireless communications are accelerating into the realm of higher data rates from hundreds of megabits to tens of gigabits per second. Increase in data rate requires higher throughput and higher utilization of spectral bandwidth. At the same time, we are seeing a demand for smaller chipsets with lower power budgets. Digital basebands with increased energy-efficiency are needed while fitting wit...

This paper presents the design and analysis of a 5.5 V Class-D stage used in two fully integrated watt-level, +32.0 dBm and +29.7 dBm, outphasing RF Power Amplifiers (PA) in standard 130 nm and 65 nm CMOS technologies. The Class-D stage utilizes a cascode configuration, driven by an AC-coupled low-voltage driver, to allow a 5.5 V supply in the 1.2/2.5 V technologies without excessive device vol...