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

Abstract

This paper proposes a broadband Class EF power amplifier based on a low-pass filter matching structure. Based on the theory of Class EF power amplifiers, the optimal fundamental load impedance required is derived. A broadband matching circuit is then designed using a low-pass filter prototype. In the meantime, a compact harmonic control circuit is proposed to meet the harmonic impedance requirements of class EF power amplifiers. In order to validate the effectiveness of the proposed method, a 2.6-3.6 GHz broadband class EF power amplifier is designed and fabricated. Measurement results show that the output power is between 40.68 dBm and 41.6 dBm at 1 dB compression point in 2.6-3.6 GHz. From 62% to 78% drain efficiency is obtained with gain greater than 10 dB.

Wideband Class‐F power amplifier design based on harmonic control analysis and bandwidth expansion structure

“…The radio frequency choke coil is replaced by a quarter wavelength line to prevent the high-frequency signal from leaking to the DC voltage source and to provide a zero-impedance condition for even harmonics. 6,7 The harmonic control network design is based on the harmonic trap concept, as shown in Figure 1B. 8 The network consists of a series of transmission lines with λ/4 length and two parallel open-circuited stubs, including TL4 and TL5, with lengths of λ/8 and λ/12, respectively.…”

“…Figure 1A gives a schematic diagram of a Class‐F PA. The radio frequency choke coil is replaced by a quarter wavelength line to prevent the high‐frequency signal from leaking to the DC voltage source and to provide a zero‐impedance condition for even harmonics 6,7 …”

An ultra-broadband power amplifier by using a simple analysis method

“…Meanwhile, drain efficiency of from 29% to 32% is achieved in 1.0-4.0 GHz. [29], the conventional class EFJ PA in Ref [8] and the class-J in [30], while having similar drain efficiency. Overall, the proposed method can effectively widen the bandwidth of class EFJ PA, while provide a good balance between drain efficiency and bandwidth.…”

Optimization design of fragment-type filtering matching network for continuous inverse class-F power amplifier

“…As wireless spectrum resources grow increasingly constrained, the continuous operational bandwidth in future mobile communication systems is often limited. As a result, the carrier aggregation technology is employed to aggregate discontinuous frequency bands over a broadband spectrum for high-speed data transmission, which requires the power amplifiers (PAs) [1,2,3,4] to be able to operate efficiently over a wider frequency range [5,6,7,8,9,10].…”