A 28-GHz Cascode Inverse Class-D Power Amplifier Utilizing Pulse Injection in 22-nm FDSOI

Nourhan Elsayed,Baker Mohammad,Hani Saleh,Mihai Sanduleanu

doi:10.1109/access.2020.2996907

Nourhan Elsayed, Baker Mohammad + Show 2 more

Open Access

https://doi.org/10.1109/access.2020.2996907

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Abstract

Current Mode Class-D (CMCD) Power Amplifiers are of particular interest in outphasing transmitters or Doherty configuration. This is because the output capacitance can be absorbed in the RLC output matching network and 100% theoretical efficiency. In this paper, a 28 GHz current mode (inverse) Class-D power amplifier was simulated, implemented, and measured in 22nm FDSOI. In order to overcome the breakdown voltages of the devices, the amplifier employs a stacked topology, which enables higher output powers and efficiency. The stacked transistors are also pulse injected to further increase the efficiency. Measurement results shows a peak PAE of 46%, peak drain efficiency (DE) of 71% and a saturated output power of 19 dBm. The implemented CMCD PA reports the best performance in literature compared to other CMOS based CMCD PAs.

Highlights

The performance of a power amplifier (PA) is an essential factor in the performance of a transmitter as a whole when it comes to efficiency
This paper presents design, simulation, and measurements of a Current Mode Class-D (CMCD) PA at 28 GHz utilizing Globalfoundries 22nm FDSOI technology
We are able to report the best measured peak power added efficiency (PAE) in literature compared to other CMCD PAs in CMOS

Summary

INTRODUCTION

The performance of a power amplifier (PA) is an essential factor in the performance of a transmitter as a whole when it comes to efficiency. Switched-mode PAs (SMPA) are usually designed to operate at the maximum efficiency with the highest output power. This scheme is suitable for signals with a constant envelope. Such PAs are Class-E, Class-F, and Class-D (both voltage and current mode) [6], [7]. Current mode (inverse) Class-D (CMCD), introduced in [8], is able to achieve the largest peak power with a theoretically 100% efficiency. The paper is organized as follows: Section II will discuss the principle of operation of the classical CMCD, Section III will present the design methodology of the proposed CMCD and introduce the concept of utilizing a cascode topology along with pulse injection.

CONVENTIONAL CMCD PA

MEASUREMENTS RESULTS

CONCLUSION