Linear PA Design. Conventional High-Efficiency Amplifier Modes. Class AB PAs at GHz Frequencies. Practical Design of PAs. Overdrive and the F Mode. Switching Mode Amplifiers for RF Applications. Modes Signals, Modulation Systems, Nonlinearities. Efficiency Enhancement Techniques. Power Bias Circuit Architecture. Linearization

The generation of RF/microwave power is required not only in wireless communications, but also applications such as jamming, imaging, RF heating, and miniature dc/dc converters. Each application has its own unique requirements for frequency, bandwidth, load, power, efficiency, linearity, cost. generated by a wide variety techniques, implementations, active devices. Power amplifiers are incorporated into transmitters similarly architectures, including linear, Kalm, envelope tracking,...

The design and implementation of a class-J mode RF power amplifier is described. experimental results indicate the mode's potential in achieving high efficiency across extensive bandwidth, while maintaining predistortable levels linearity. A commercially available 10 W GaN (gallium nitride) electron mobility transistor device was used this investigation, together with combination waveform measurements, active harmonic load-pull theoretical analysis mode. Targeting working bandwidth 1.5-2.5...

A novel formulation for the voltage waveforms in high efficiency linear power amplifiers is described. This demonstrates that a constant optimum and output can be obtained over continuum of solutions by utilizing appropriate harmonic reactive impedance terminations. specific example confirmed experimentally. new has some important implications possibility realizing broadband >10% RF amplifiers.

A novel power amplifier (PA) architecture, the Load Modulated Balanced PA (LMBA), is presented. The LMBA able to modulate impedance seen by a pair of RF transistors in quadrature balanced configuration, varying amplitude and phase an external control signal. This enables efficiency be optimized dynamically at specific backoff levels frequencies. Unlike Doherty PA, load active devices can modulated upwards or downwards, both resistively reactively, with minimal loss combination efficiency....

The extended continuous class-F mode RF power amplifier (PA) is presented for the first time. introduction and experimental validation of this novel PA demonstrates a new design space over wide band frequencies. This paper will show that high output drain efficiency, equivalent to mode, can be maintained by varying reactive components fundamental second harmonic impedances in accordance with formulation voltage waveform. Additionally it shown that, both phase magnitude impedances, yet wider...

This paper presents the design and characterization of a load modulated balanced amplifier for telecom base station applications adopting novel mode operation. The theory operation is described explaining main differences compared to Doherty amplifiers, in particular RF bandwidth advantages and, on other hand, intrinsic nonlinear behavior. specific strategy that adopts prematching back-off broadband matching explained detail. A prototype, based 25-W GaN packaged devices, has been fabricated...

In this paper, an extended version of the continuous class- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</i> <sup xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> mode power amplifier (PA) design approach is presented. A new formulation describing current waveform in terms just two additional parameters, while maintaining a constant half-wave rectified sinusoidal voltage waveform, allows multiple solutions fundamental and second-harmonic...

A theory is presented which capable of predicting the power load-pull contours a GaAs FET in convenient mathematical formulation. Although based on some initial simplifying assumptions, predicted are shown to be good agreement with experimental measurements.

This paper presents, for the first time theoretical introduction and experimental validation of Continuous Class-F Mode Power Amplifier that provides a new design space high efficiency broadband power amplifiers. Starting from standard class-F mode, this work shows it is possible to maintain constant or even improved output coupled variations fundamental second harmonic impedances. The investigation was carried out on GaAs pHEMT devices demonstrates near between 82% 87% can be achieved along...

A novel graphical power amplifier (PA) design tool, the "clipping contour," is introduced and described. Using now well-publicized continuous Class-B/J voltage waveform formulation as a starting point, process derived that allows contours to be constructed on Smith chart define "zero-grazing" fundamental harmonic impedance conditions. Theoretical equations are defined solved whereby can drawn in real time computer-added environment. key result from this theory definition of 2-D space opens...

A novel, highly efficient and broadband RF power amplifier (PA) operating in "continuous class-F" mode has been realized for first time. The introduction experimental verification of this new PA demonstrates that it is possible to maintain expected output performance, both terms efficiency power, over a very wide bandwidth. Using recently established continuous class-F theory, an matching network was designed terminate the three harmonic impedances. This resulted delivering average drain 74%...

Summary form only given, as follows. A novel, highly efficient and broadband power amplifier operating in continuous class-F mode has been realized. The introduction experimental verification of this new PA demonstrates that it is possible to maintain expected output performance, both terms efficiency power, over a very wide bandwidth. Using recently established theory, delivering an average 74% 10.5W for octave bandwidth

Results from a fully implemented class-J RFPA (RF power amplifier) are presented for the first time, which demonstrate this mode's high efficiency potential across substantial bandwidth. Using commercially available 10W GaN (gallium nitride) HEMT device, and waveform measurement active load-pull capability at Cardiff University, operation has demonstrated drain efficiencies between 60-70% 1.35-2.25 GHz (50%) bandwidth whilst delivering 10 Watts of 2dB compression point. Realisation design...

The Load Modulated Balanced Amplifier (LMBA) uses a control signal (CSP), injected to the normally terminated port at output coupler of balanced amplifier (BA), modulate BA transistor's impedance. hybrid circuit demonstrator described here metal-backed multilayer organic substrate and GaN discrete devices. Maximum power levels above 39.5 dBm are achieved around P3dB. DE 60% is seen between 4.5 7.5 GHz for back-off 7 dB with fixed CSP 1 W, bias 18 28 V.

This paper presents a broadband efficient power amplifier (PA) targeting sub-6-GHz 5G base station applications. Due to the demanding requirements in both peak-to-average ratio (PAPR) and bandwidth systems, we employ combination of load supply modulation for efficiency enhancement. Active matching, implemented using an RF-input load-modulated balanced (LMBA) architecture, enables octave-bandwidth operation. Supply modulation, which is carrier frequency agnostic, then used further extend...

This article presents an orthogonal load-modulated balanced amplifier designed to mitigate the effects of load mismatch on power-added efficiency and output power amplifier. is achieved by electronically adjusting ratio between two input signals (PA) (in phase amplitude) reactive termination at nominally isolated port. The mode operation PA described using a theoretical analysis that highlights role different tuning parameters confirmed simulations simplified transistor model. design...

This paper presents a novel formulation for the inverse class-F mode of operation, termed “continuous mode”, resulting in an extended or continuous set ‘allowed’ current waveforms. In comparison to classical mode, this approach provides much wider design space realization broadband power amplifiers, where output performance can be maintained through proper termination harmonic components over bandwidth. By varying simultaneously susceptance fundamental and second terminations, it will shown...

The load modulated balanced amplifier (LMBA) technique uses a control signal, injected at the output coupler, to modulate impedance of transistors. A 14.1-W X-band LMBA is reported, integrating for first time balanced, driver, and signal amplifiers in single microwave monolithic integrated circuit. Load modulation bias settings are used demonstrate that high circuit efficiency can be achieved as adjusted operation three RF-power regimes; 1.5, 5.6, 14.1 W constant input power 22 dBm....