Design of Broadband, High-Efficiency, and High-Linearity Gan Hemt Class-J Rf Power Amplifier

Abstract

In this paper, the design of a broadband, high-efficiency, and high-linearity Class-J GaN HEMT RF power amplifier (PA) over 1.6-2.6 GHz is explained. The source impedance is conjugatematched to the input impedance of the device resulted from small signal simulation to make a high-gain power amplifier. The load impedance related to the maximum power added efficiency (PAE) and maximum output power is obtained by pulling the only fundamental and second harmonic components over frequency bandwidth. Thus, not only a high-efficiency PA but also a high-linearity PA is formed. The input and output matching networks are implemented by microstrip transmission lines. The theoretical PA designed is optimized using computer-aided simulations. The fabricated PA provides output power in the range of 38-39.9 dBm with 60%-73% PAE and 15-16.3 dB power gain across the band. The worst measured ACLR1 as the PA is fed by the CDMA signal with 1.2288 MHz bandwidth is at a level of −38.6 dBc. A close agreement between the measured and simulation results is observed due to the use of high-order harmonic balance simulator and high-accuracy implementation procedure.

High‐power multi‐octave laterally diffused metal–oxide–semiconductor power amplifier with resistive harmonic termination

“…This property is mostly attributed to the high-power density of GaN devices, which leads to low chip areas and consequently low intrinsic capacitances. The power amplifier presented in [28] is another example of 10 W power amplifiers that were designed by the continuous waveform engineering method, and exhibit nearly one octave bandwidth. Some recent methods rely on the harmonic generation of nonlinear effective output capacitance of the devices, which is useful for drain waveform engineering [4,5].…”

“…This property is mostly attributed to the high‐power density of GaN devices, which leads to low chip areas and consequently low intrinsic capacitances. The power amplifier presented in [28] is another example of 10 W power amplifiers that were designed by the continuous waveform engineering method, and exhibit nearly one octave bandwidth.…”

Novel Design Theory for High-Efficiency and High-Linearity Microwave Power Amplifier Based on 2nd Harmonic: Enhanced Class-J

“…In this concept, the drain voltage and current waveforms contain only two first harmonic components, eliminating shorted-circuit condition at the second harmonic. The maximum drain voltage may be three times of dc drain voltage, limiting designers to use any kind of transistor [11]. Fortunately, among today's technologies, GaN HEMT with high breakdown voltage and high band gap can be considered for this class operation [12].…”