New compact 28 GHz transceiver that helps double polarized MIMO
Researchers at Tokyo Institute of Technology (Tokyo Tech) and NEC Corporation have jointly developed a 28 GHz phased array Transceiver that supports double polarized MIMO for fifth generation mobile devices (5G). Advances in 5G will benefit a number of industries ranging from healthcare, manufacturing and transportation to education and entertainment that require high bandwidth and high quality connectivity.
As countries roll out or prepare for 5G services, researchers are stepping up efforts to facilitate the deployment of 5G infrastructure. Dual polarized phased array transceivers are an attractive class of antenna systems that can transmit data simultaneously over horizontally and vertically polarized waves. Numerous studies have shown that double polarized MIMO can improve the data rate and spectrum efficiency in 5G radio units. A problem with these systems, however, is cross polarization leakageThis leads to a deterioration in the signal quality, especially in the millimeter wave band.
Now Kenichi Okada’s laboratory in the electrical engineering and electronics department of Tokyo Tech and the NEC Corporation in Japan have developed a transceiver that can cancel cross-polarization interference using a built-in horizontal and vertical (H / V) canceller. Tests have shown that the error vector size in 256QAM can be improved from 7.6% to a more desirable lower value of 3.3% with this new leak cancellation technique. “The cancellation signals are generated for the horizontal and vertical polarization on the transmission side, so that the cross-polarization loss caused by the transmitter / receiver chip, the housing, the circuit board and the antenna can be canceled,” say the researchers.
The transceiver was fabricated using an inexpensive, mass-produced silicon CMOS Technology that takes up an area of only 16 mm2. The researchers believe the new circuit can be installed in a wide variety of applications that 5G will enable in the future. What is important is that your transceiver improves spectrum efficiency while minimizing device size and setup costs.
The results will be presented at the 2020 Symposia on VLSI Technology and Circuits (VLSI 2020), which will take place online from June 14th. The paper was also selected as one of the technical highlights of the conference.
This research is supported by Japan’s Ministry of Internal Affairs and Communications (JPJ000254).
 Phased-Array: Description of an electrically controllable antenna array.
 Dual-polarized MIMO: Dual-polarized multiple-input-multiple-output (MIMO) is an antenna system for wireless communication that can improve transmission capacity by using multiple antennas that transmit signals at the same time.
 Cross polarization leakage: A type of signal leakage caused by interfering horizontally and vertically polarized signals.
 Error vector magnitude: A measure of the level of interference calculated from the difference between the ideal signal sent and the signal actually received.
 256QAM: The highest digital modulation method for converting digital data into radio waves and electrical signals.
 CMOS: Complementary Metal Oxide Semiconductor, the main processing method used to create integrated circuits.
Technology Session (Video): CF2 – RF and MM Wave Circuits
Session Title: A 28 GHz CMOS phased array beamformer that supports dual polarized MIMO with cross polarization leak suppression
Authors: Pang, J. et al.
Conference: 2020 Symposia on VLSI Technology and Circuits