Power consumption is a bottleneck for 5G communication and even 6G wireless communication in the future. Among all the components, power amplifiers (PA) consume the most power in wireless terminals or base stations. To improve power efficiency, Tianjin University Microelectronic Team of Wireless Communication and Sensor Technology put forward transformer-based parallel-series load modulation, a novel topology and theory of PA featuring high power backoff efficiency.
As next-generation communication technologies of 5G millimeter wave and 6G greatly improve the rate of high data communication, technologies such as Quadrature Amplitude Modulation (QAM), Orthogonal Frequency Division Multiplexing (OFDM) and Carrier Aggregation that are generally used to increase the rate of data communication have greatly raised the peak to average power ratio (PAPR) of communication signals, which means better linearity is required in the wireless communication system.
The technology the team put forward is used to deal with high power consumption of the high-order complex matching network on silicon-based chips. Meanwhile, the structure of this high-order load modulation is transformed into the transformer-based differential matching form to reduce size and power consumption, and adaptive biasing circuits and nonlinear compensating circuits featuring high-speed broadband are integrated into the PA. Based on a 55nm bulk CMOS process used in traditional commercial fields, this Doherty PA achieves 25.5dBm PSAT and 20.4%/14.2% PAE at 6-/12-dB PBO. Compared with the 5G millimeter-wave CMOS PA chip that has dominated the world in recent years, this compact PA chip achieves high-linear output power and the highest backoff efficiency at 12-dB PBO.
This research result was put forward in a paper entitled A 28-GHz Compact 3-Way Transformer-Based Parallel-Series Doherty Power Amplifier with 20.4%/14.2% PAE at 6-/12-dB Power Back-Off Operating and 25.5dBmPSATin 55nm Bulk CMOS. This paper was presented by Tianjin University at the 2022 IEEE International Solid-State Circuits Conference (ISSCC 2022).
During the conference, Tianjin University also offered a Demo session elaborating on the innovative technology of millimeter-wave power amplifiers. The first author and the corresponding author of this paper both come from TJU, with Zonglin Ma, a PhD student, being the first author and Pros. Kaixue Ma, the leader of TJU Microelectronic Team of Wireless Communication and Sensor Technology, being the corresponding author.
ISSCC - the worldwide flagship conference sponsored by IEEE SSCS – begun in 1953. It is the foremost global forum for presentation of advances in solid-state circuits and systems-on-a-chip (SoC). Known as the “Chip Olympics”, ISSCC has represented the highest international academic level in integrated circuits for decades, and papers presented at this conference will show the development of chip technologies and the trend of the chip industry. Moreover, many milestone inventions and technological breakthroughs in integrated circuits usually make their debut at this conference. This year’s ISSIC was held in San Francisco from February 20-24, 2022.
Supported by Tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology, TJU Microelectronic Team of Wireless Communication and Sensor Technology has a solid research foundation in radio frequency, microwave and terahertz. The team is also financially supported by “National Science and Technology Major Project of the Ministry of Science and Technology of China”, “National Key R&D Program of China”, “National Science Fund for Distinguished Young Scholars”, “The Key Program of National Natural Science Foundation of China” and many other programs. The team has achieved a number of research results in integrated circuits and systems. In terms of simulation software, the team has developed Neuro Modeler, a microwave optimization simulation software with completely independent intellectual property rights. The team also has a world-class scientific research and testing platform that integrates microwave terahertz microelectronic system design, device parameter extraction, and communication integrated system reliability testing. The operational frequency of equipment is capable of continuously covering up to 1140 GHz. The team also develops a complete heterogeneous integrated microsystem processing platform. What is more, under the support of “National Science Fund for Distinguished Young Scholars”, Pros. Ma’s team has been conducting research on in 5G millimeter-wave transceiver chips and phased array chips for a long time. Focusing on technical problems like the multi-frequency fusion and reconfiguration of millimeter-wave broadband, the team originates a method to combine silicon-based millimeter wave with SoC design at different frequency bands and standards. In addition, the team also cooperates with leading enterprises in related industries to put the 5G millimeter-wave technology into use.
By School of Microelectronics
Editors: Lin Nan, Sun Xiaofang
