Figure 1. The new transceiver measures only 3 mm x 4 mm. The proposed chip, fabricated in a standard 65-nanometer CMOS process, takes up a total area of just 12 mm2.

Researchers at the Tokyo Institute of Technology have devised a strategy to support high-speed mobile data access using the millimeter-wave spectrum for a fifth-generation (5G) cellular network — the highly-anticipated wireless network of the near future. Measuring just 3 mm by 4 mm, this tiny transceiver could help improve performance of 5G and Internet of Things (IoT) devices. It is anticipated that 5G services will enable higher data throughput for applications such as live-streaming high-definition (HD) video and for the potentially trillions of new IoT devices that can share data around the clock, as well as to increase the speed and responsiveness of communication networks overall.

The proposed device uses two techniques to optimize performance: beamforming, an efficient signal processing method that involves "pointing" antenna arrays in optimal directions; and dual polarized MIMO capability, which utilizes multiple antennas at both ends of the transceiver (transmitter and receiver) to boost data rates. This means that its array of antennas can respond to both horizontal and vertical radio waves at the same time. The small size of the chip is well-suited for the anticipated demand for high-performance, area-efficient transceivers to use in tiny portable 5G sensors and devices. The required on-chip area is minimized compared to the conventional switch-based bi-directional approach. The researchers developed a bi-directional amplifier that completely shares the inter-stage matching networks between the transceiver and the receiver.

Preliminary testing showed that the maximum data rate achieved was 15 gigabits per second in the 64-QAM format. This data rate is 25 percent higher than that achieved by previous comparable models.