Cornell University researchers have devised a semiconductor chip poised to advance the development of 6G wireless technology by enabling smaller devices to function at the higher frequencies required. With the demand for greater bandwidth at higher frequencies in the next generation of wireless communication, this chip introduces a vital time delay, ensuring that signals transmitted across multiple arrays synchronize at a single spatial point without degradation.
Their study, titled “Ultra-Compact Quasi-True-Time-Delay for Boosting Wireless Channel-Capacity,” was published in Nature on March 6, with Bal Govind, a doctoral student in electrical and computer engineering, as the lead author. While current wireless communications, such as 5G phones, typically operate at frequencies below 6 gigahertz (GHz), the pursuit of 6G cellular communications targets frequencies above 20 GHz, offering increased bandwidth for faster data transmission—anticipated to be 100 times faster than 5G.
However, higher frequencies are susceptible to greater data loss in the environment, necessitating an efficient method for relaying data. Instead of relying on a single transmitter and receiver, most 5G and 6G technologies utilize phased arrays of transmitters and receivers for enhanced energy efficiency.
Govind explained, “Every frequency in the communication band experiences different time delays. Our challenge is to transmit high-bandwidth data economically, ensuring alignment of signals of all frequencies at the correct time and location.”
Alyssa Apsel, professor of engineering and senior author, emphasized the importance of maintaining signal integrity throughout the delay process. Collaborating with postdoctoral researcher Thomas Tapen, Govind designed a complementary metal-oxide-semiconductor (CMOS) capable of tuning time delay over an ultra-broad bandwidth of 14 GHz, with precise phase resolution.
The team innovatively employed three-dimensional waveguides to create a series of 3D reflectors, forming a “tunable transmission line.” This integrated circuit, occupying a mere 0.13-square-millimeter footprint, surpasses traditional wireless arrays in channel capacity, effectively doubling the data rate. By enhancing the projected data rate, the chip promises faster service delivery, facilitating increased data transmission to cellphone users.
Apsel highlighted the challenge of balancing size and efficiency in phased arrays and the industry’s tendency to prioritize phase delay over time delay. The team’s approach challenges this norm, presenting a significant advancement in communications technology.
“If we can increase channel capacity tenfold by altering a single component,” Apsel remarked, “it represents a substantial breakthrough in communications.”
