A Review of 5G Power Amplifier Design at cm-Wave and mm-Wave Frequencies

Abstract

The 5G wireless revolution presents some dramatic challenges to the design of handsets and communication infrastructures, as 5G targets higher than 10 Gbps download speed using millimeter-wave (mm-Wave) spectrum with multiple-input multiple-output (MIMO) antennas, connecting densely deployed wireless devices for Internet-of-Everything (IoE), and very small latency time for ultrareliable machine type communication, etc. The broadband modulation bandwidth for 5G RF transmitters (i.e., maximum possibly even above 1 GHz) demands high-power efficiency and stringent linearity from its power amplifier (PA). Additionally, the phased-array MIMO antennas with numerous RF front-ends (RFFEs) will require unprecedented high integration level with low cost, making the design of 5G PA one of the most challenging tasks. As the centimeter-wave (cm-Wave) 5G systems will probably be deployed on the market earlier than their mm-Wave counterparts, we will review in this paper the latest development on 15 GHz and 28 GHz 5G cm-Wave PAs extensively, while also covering some key mm-Wave PAs in the literature. Our review will focus on the available options of device technologies, novel circuit and system architectures, and efficiency enhancement techniques at power back-off for 5G PA design.

Implementation Challenges and Opportunities in Beyond-5G and 6G Communication

“…Finally, because of the limited output power capability of silicon-based technologies, Gallium Nitride (GaN) or other III-V devices with their unique properties of high sheet charge, high electron mobility and wide bandgap are needed to fulfill the output-power and efficiency requirements [40]. For example, GaN devices can deliver a power density of 3.6 W/mm at 86 GHz in continuous wave operation and a P max of 3.6 Watt at 83 GHz was reported in pulse mode [44]. For an efficient implementation, there is also an ongoing effort to co-integrate GaN or III-V devices with CMOS or BiCMOS [45].…”

A Survey on RF and Microwave Doherty Power Amplifier for Mobile Handset Applications

“…eliminates the signal splitting device and minimizes the wasted energy of the driving power into the peaking path. The Dual-Input DPA transmitter in Figure 9 consists of a DSP and a signal conversion block [62]. The DSP performs the modulation, interpolation, and digital pre-distortion (DPD) on an input signal.…”

Review of efficiency enhancement techniques and linearization techniques for power amplifier

“…Class A has highest linearity but lowest efficiency (50 % ) whereas Class C can offer highest efficiency (theoretically maximum of 100 % ) but is most nonlinear 5 . The output power requirement of power amplifier (PA) will depend on the cell size as discussed in Lie et al 6 …”