A broadband microwave GaN HEMTs class EF₃ power amplifier with π-type network

Abstract

A GaN HEMTs class EF 3 power amplifier (PA) with π-type network for broadband operation is presented in this paper. The π-type network is constructed by shunt capacitance, series inductance and finite dc-feed inductance, where the series inductance includes the parasitic inductance effects of transistor. As a result, the topology can make full use of the parasitic effects of transistor to raise the operation frequency. Moreover, it is found that this topology can also increase the frequency bandwidth. For demonstration purpose, a PA prototype based on the topology is fabricated. Experimental results show that the amplifier can operate from 2.9 GHz to 4.0 GHz (fractional bandwidth 31.8%) with a measured drain efficiency higher than 67%, and the output power is greater than 37.4 dBm. The proposed structure can be a good candidate for design of high efficiency and broadband class E power amplifiers. Keywords: class EF 3 , power amplifier, GaN HEMT, π-type network Classification: Microwave and millimeter-wave devices, circuits, and modules

Design theory of broadband high‐efficiency continuous Class EF power amplifier based on new continuous factor

“…The minimum of is found to be −0.84 at , as shown in Figure 4. Since the drain voltage waveform of an ideal Class EF PA is flat, the fundamental and third‐harmonic drain voltage components must be “out‐of‐phase,” that is, they have to be opposite in sign, to properly shape the voltage waveform 16 . Therefore, can only be −0.47.…”

Design of broadband Class EF power amplifier based on low-pass filter matching structure

“…The hybrid class EF PAs presented in [20] have received more and more attention recently for which they have the advantages of both class E and class F PAs. The class EF PAs absorb the soft switching characteristic of class E that enables it to achieve 100% drain efficiency while having a low peak drain voltage that is similar to that of class F PAs [21,22,23]. However, due to the influence of the output capacitance of the transistor, the class EF PAs often cannot have a wider bandwidth at higher frequencies [24,25].…”