Introducing a Transceiver that Can Tap into the Higher Frequency Bands of 5G Networks

A novel phased-array beamformer for the 5G millimeter wave (mmWave) band has been recently developed by researchers at Tokyo Tech and NEC Corporation. Their innovative design applies two well-known techniques — the Doherty amplifier and digital predistortion — to a mmWave phased-array transceiver and overcomes the issues in conventional designs, producing exceptional energy and area efficiency and outperforming other state-of-the-art 5G transceivers.
5G networks are becoming more prevalent worldwide. Many consumer devices that support 5G are already benefiting from increased speeds and lower latency. However, some frequency bands allocated for 5G are not effectively utilized owing to technological limitations. These frequency bands include the New Radio (NR) 39 GHz band, but actually span from 37 GHz to 43.5 GHz, depending on the country. The NR band offers notable advantages in performance over other lower frequency bands 5G networks use today. For instance, it enables ultra-low latency in communication along with data rates of over 10 Gb/s and a massive capacity to accommodate several users.

However, these feats come at a cost. High-frequency signals are attenuated quickly as they travel through space. It is, therefore, crucial that the transmitted power is concentrated in a narrow beam aimed directly at the receiver. This can, in principle, be achieved using phased-array beamformers, transmission devices composed of an array of carefully phase-controlled antennas. However, working at high frequency regions of the NR band decreases the efficiency of power amplifiers as they tend to suffer from nonlinearity issues, which distort the transmitted signal.

To address these issues, a team of researchers led by Professor Kenichi Okada from Tokyo Institute of Technology (Tokyo Tech), Japan, have recently developed, in a new study, a novel phased-array beamformer for 5G base stations. Their design adapts two well-known techniques, namely the Doherty amplifier and digital predistortion (DPD), into a mmWave phased-array transceiver, but with a few twists. The researchers present their findings in the 2022 IEEE Symposium on VLSI Technology and Circuits.

The Doherty amplifier, developed in 1936, has seen a resurgence in modern telecommunication devices owing to its good power efficiency and suitability for signals with a high peak-to-average ratio (such as 5G signals). The team at Tokyo Tech modified the conventional Doherty amplifier design and produced a bi-directional amplifier. What this means is that the same circuit can both amplify a signal to be transmitted and a received signal with low noise. This fulfilled the crucial role of amplification for both transmission and reception. “Our proposed bidirectional implementation for the amplifier is very area-efficient. Additionally, thanks to its co-design with a wafer-level chip-scale packaging technology, it enables low insertion loss. This means that less power is lost as the signal traverses the amplifier,” explains Professor Okada.

Despite its several advantages, however, the Doherty amplifier can exacerbate nonlinearity problems that arise from mismatches in the elements of the phased-array antenna. The team addressed this problem in two ways. First, they employed the DPD technique, which involves distorting the signal before transmission to effectively cancel out the distortion introduced by the amplifier. Their implementation, unlike the conventional DPD approaches, used a shared look-up table (LUT) for all antennas, minimizing the complexity of the circuit. Second, they introduced inter-element mismatch compensation capabilities to the phased array, improving its overall linearity. “We compared the proposed device with other state-of-the-art 5G phased-array transceivers and found that, by compensating the inter-element mismatches in the shared-LUT DPD module, ours demonstrate a lower adjacent channel leakage and transmission error,” remarks Professor Okada. “Hopefully, the device and techniques described in this study will let us all reap the benefits of 5G NR sooner!”

Acknowledgement
This work was partially supported by the Ministry of Internal Affairs and Communications in Japan (JPJ000254).

About Tokyo Institute of Technology

Tokyo Tech stands at the forefront of research and higher education as the leading university for science and technology in Japan. Tokyo Tech researchers excel in fields ranging from materials science to biology, computer science, and physics. Founded in 1881, Tokyo Tech hosts over 10,000 undergraduate and graduate students per year, who develop into scientific leaders and some of the most sought-after engineers in industry. Embodying the Japanese philosophy of “monotsukuri,” meaning “technical ingenuity and innovation,” the Tokyo Tech community strives to contribute to society through high-impact research. https://www.titech.ac.jp/english/

About NEC Corporation

NEC Corporation has established itself as a leader in the integration of IT and network technologies while promoting the brand statement of “Orchestrating a brighter world.” NEC enables businesses and communities to adapt to rapid changes taking place in both society and the market as it provides for the social values of safety, security, fairness and efficiency to promote a more sustainable world where everyone has the chance to reach their full potential. For more information, visit NEC at https://www.nec.com.






Topic: Press release summary

Microchip Introduces High-Reliability, Extended-Temperature Ethernet PHY Transceiver for Aerospace and Military Ground-Based Applications

September 29, 2020, New Delhi – Aircraft, military vehicle and ground-based systems that rely on intelligence, information and secure connectivity to support mission success are enabled by enhanced technology designed to operate in extreme temperatures and environmental events. Microchip Technology Inc. (Nasdaq: MCHP) today announced its new VSC8540/41 Gigabit Ethernet PHY RMII / RGMII Transceiver – a Commercial Off-The-Shelf (COTS)-based device upgraded for avionics and military applications.

 

Based on its COTS technology deployed in other industries, Microchip’s Gigabit Ethernet Physical Layer (PHY) transceiver features a military-grade, high-reliability (HiRel) plastic package that meets requirements for applications ranging from fighting vehicles to cockpit avionics and in-flight communication systems. The VSC8541RT Ethernet transceiver is a solution with Reduced Gigabit Media Independent Interface (RGMII) and G.M.I.I., and also supports R.M.I.I and M.I.I. Megabit interface. The transceiver is latch-up immune to atmospheric radiation effects while performing at a temperature range of –55 to 125 degrees Celsius. Product specifications include wafer and assembly lot full traceability; description of testing, electrical parameters and fault coverage; qualification report; and certificate of compliance.

 

As COTS-based technology, Microchip’s Ethernet PHY RMII / RGMII transceiver allows system designers to begin implementation with COTS devices before moving to military-grade components, reducing significant development time and cost.

 

Microchip’s RMII / RGMII transceiver is the latest high-reliability solution designed for extreme environments, building on the company’s aerospace, defense and space product portfolio. The device complements the company’s extended-temperature product offering that includes following qualified devices:

:

  • 8-bit AVR® microcontrollers with embedded ADC/DAC, Controller Area Network (CAN) and motor control interfaces
  • 16-bit dsPIC® digital signal controller for digital power management
  • 32-bit ARM microcontroller with memory protection mechanisms and 100 Mbit Ethernet connectivity
  • 200 Megasamples Per Second (Msps) standalone 16-bit ADC

 

While continuing to introduce innovations including those based on COTS technology, Microchip teams with system manufacturers and integrators on obsolescence management, supporting customers’ efforts to minimize redesign work and lengthen life cycles, thereby reducing overall system costs.

 

Availability

The VSC8540/41 Gigabit Ethernet PHY RMII / RGMII transceiver in a plastic or ceramic package is now sampling. Complete product information is at www.microchip.com.

 

Resources:

 

Application Image: https://www.flickr.com/photos/microchiptechnology/50320611468/

 

Product image: https://www.flickr.com/photos/microchiptechnology/50321468502/