Abstract: Class-F microwave monolithic integrated circuit (MMIC) power amplifiers (PA) fabricated in a GaN technology are reported. Field-plated GaN HEMT devices are used for highpower performance. Two MMICs are reported. The first class-F MMIC PA operating at 2.0GHz achieved a power-added efficiency (PAE) of 50% with 38dBm output power and 6.2W/mm power density. A second class-F PA operating a...

In this paper, we examine Decision Graphs, a generalization of decision trees. We present an inference scheme to construct decision graphs using the Minimum Message Length Principle. Empirical tests demonstrate that this scheme compares favourably with other decision tree inference schemes. This work provides a metric for comparing the relative merit of the decision tree and decision graph form...

A class of transistor amplifiers is described in which high input impedance is achieved with good bias stability. Input impedances of the order of _megohms shunted by one or two micramicrofarads are easily realized with simple circuits, and higher impedances may be obtained with more elaborate circuitry. Other important properties are that input shunt capacitance can be almost completely elimin...

Digital signal processing (DSP) techniques are being incorporated in the design of modern power amplifiers (PA) and as the speed of DSP advances it is envisioned that DSP will develop to a point where algorithms will provide signals at RF particularly for switching amplifiers. The digital transmitter has many potential benefits such as the absence of aging or tuning problems, reconfigurability,...

This paper presents a new procedure to design of high efficiency class E power amplifiers (PAs) using nonlinear transistors. The active device (MESFET-ATF34143) has been investigated and load harmonic networks have also been designed to match the requirement. By using the new procedure, the power added efficiency (PAE) of PAs could be increased to over 70%. The effect of the stabilized resistor...

− The results of exact time domain analysis of the switched-mode tuned Class E power amplifiers with a quarterwave transmission line are presented with analytical determination of the optimum load network parameters. Effects of the quarterwave transmission line and collector capacitance on the current and voltage waveforms are discussed and analyzed. The ideal collector voltage and current wave...

The tradition of implementing analogue circuits by means of voltage amplifiers is almost as old as the concept of electronic circuit design. The integrated electronic circuit, however, is a relatively new concept. Furthermore, integrated electronic circuits have significantly different limitations and strengths to the conventional discrete electronic circuits have. Since the active devices in i...

The nominal operating condition of Class E power amplifiers with parallel-connected nonlinear parasitic capacitance and linear capacitance at any duty ratio has been studied in this article. Basic design equations are derived analytically. Using these equations, the component values for ensuring nominal operation at any given duty ratio can be conveniently found. Furthermore, the design equatio...

In this work, dynamic load modulation of high power amplifiers using a varactor-based tunable matching network is presented. The feasibility of dynamic tuning and efficiency enhancement of this technique is demonstrated using a modular design approach for two existing high efficiency power amplifiers (PA), a 7-W class-E, and a 10-W class-J power amplifier PA at 1 GHz. For this purpose and for e...