The distortion produced by a typical solid-state Class-B power amplifier is shown to consist of eight mechanisms, all of which may coexist and whose distortion products overlap to give a complex result. Methods for isolating each mechanism for study, and minimising its contribution, are given. If the avoidable distortions are designed out, Class-B amplifiers of unusually low distortion (Below 0...

Today’s wireless system requirements demand increasing performance from power amplifiers. The higher gain and output power available from today’s transistors reduce the number of amplifier stages, and improved efficiency decreases system DC power requirements and generated heat. But at these higher power and efficiency levels, power amplifier linearity needs to meet or exceed the requirements o...

A wide variety of semiconductor devices are used in wireless power amplifiers. The RF performance and other attributes of cellphone RF power amplifiers using Si and GaAs based technologies will be reviewed and compared.

The Stretched-FrOnt-Leg (SFOL) pulse is a high-accuracy distance measuring equipment (DME) developed to support alternative positioning and navigation for aircraft during global satellite system outages. To facilitate the use of SFOL pulse, it best legacy DMEs that are already deployed transmit rather than current Gaussian through software changes only. When attempting in DMEs, greatest challen...

Wide band code division multiple access (WCDMA) signals, transmitted by the base station high power amplifiers (HPAs), show high peak to average power ratios (PAPR), which results in nonlinear distortions. In this paper, using computer simulations effect of using a predistorted HPA on the symbol error rate (SER) of multi-user detectors in terms of output back-off (OBO) in the transmit power is ...

This paper presents and discusses two possible real-time digital predistortion (DPD) architectures suitable for envelope tracking (ET) power amplifiers (PAs) oriented at a final computationally efficient implementation in a field programmable gate array (FPGA) device. In ET systems, by using a shaping function is possible to modulate the supply voltage according to different criteria. One possi...

Stacked MOS power amplifiers (PA) are commonly used in SOI nodes but also have the potential to be realized bulk CMOS nodes. In this paper they analyzed millimeter wave regimes. The study focuses on key limiting factors and particular optimum number of transistors from which performance parameters such as maximum possible operating frequency, output power, efficiency achieved. Based analysis, d...

An analytical load—pull-based design methodology for three-stage Doherty power amplifiers (PAs) is presented and demonstrated. A compact output combiner network, together with the input phase delays, derived directly from transistor load—pull data requirements. The technique opens up a new space PAs reconfigurable high-efficiency back-off levels. method designed to enable high utilization by ma...

1. Introduction With the diversifying functions and increasing traffic of recent satellite communications, the amplifiers installed in satellites must provide higher power and improved efficiency. Commonly-used satellite-mounted amplifiers are, in general, either traveling wave tube amplifiers (TWTAs) or solid state power amplifiers (SSPAs) using gallium arsenide field-effect transistors (GaAs ...