Design of a high‐efficiency dual‐band class‐J/J power amplifier considering concurrent‐mode input drive

Abstract

This article analyses concurrent dual-band Class-J/J power amplifiers (PAs) with simultaneous input drive at both bands. Although it is well known that the Class-J PA has the same performance regarding the efficiency compared with the conventional Class-B PA, in this article, we show that concurrent-mode efficiency of Class-J/J dual-band power amplifier is higher than the Class-B/B counterparts much closer to their single-mode efficiency. Furthermore, it has been explained that the performance of concurrent operation of dual-band PAs is highly dependent to the design space of PA load reactance at intermodulation terms. We also explore that at intermodulation frequencies the design space includes an efficiency degradation region occurring around a specific impedance, which should be avoided when designing for concurrent operation mode. The dependency of the concurrent-mode efficiency to the nonlinearity performance of the transistor output capacitance is also considered. A concurrent dual-band Class-J/J PA operating at 1.842 and 2.655 GHz bands is implemented, where the harmonic and intermodulation control networks are designed based on closed-form equations. Measured results reveal that about 60% balanced concurrent-mode efficiency can be achieved, which outperforms recently reported counterparts. At the lower and upper bands, output powers of 41 and 40.5 dBm and efficiencies of 73.5% and 71.7% are obtained, respectively. K E Y W O R D Sclass-J, concurrent dual-band power amplifier, high efficiency, intermodulation tuning

Dual-Band Class J Power Amplifier at 2.45 and 5.8 GHz for UAVs Communications

“…9. To match second harmonic impedances, references [3] and [6] were considered. Those works added in the matching networks at the transistor's drain a λ 8 open stub at f 0 to force a short circuit at 2f 0 so in this work the same method is used but setting this stub initially at 5.8 GHz, prior optimization.…”

“…It employs 2.1 and 5 GHz as the center frequencies of each band and makes use of a matching procedure in two steps, which consists of matching at first complex to real impedances and then, real to real impedances. In [6] is presented a concurrent class J PA working at closer bands than this work, 1.842 and 2.655 GHz. The matching networks were designed for matching the harmonic impedances and the impedance for the second order intermodulation, which was relevant to obtain good efficiency.…”

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

“…In order to meet the expanded bandwidth requirements, several broadband PAs, such as Class J [11,12,13], continuous class-F (CCF) [14,15,16] and continuous inverse class-F (CCF-1) [17,18,19,20] broadband PAs with improved harmonic control have been proposed. In [14], the theory of the CCF PA was studied with the model of the gate bias voltage, which provided greater impedance matching space for high-efficiency broadband PA design.…”

Design of high‐efficiency , multi‐octave hybrid continuous mode power amplifier with novel low‐pass filtering matching network

“…Power amplifiers (PAs) as the last and most crucial stage in transmitters should support the increasing number of bands and telecommunication standards. The output‐matching network (OMN) plays an important role in the performance of the PA. A variety of topologies and design methodologies such as real frequency technique (RFT), 1 Continuous mode PA, 2–4 and filter‐based matching network are proposed for broadband and multi‐band matching network design. Recently, PA‐filter topologies attract much attention as their filtering characteristic leads to out‐of‐band rejection 5,6 …”