Low Cost Millimeter Wave Arrays for 5G and IoE Applications
The demand for high-speed wireless data and the Internet of Everything (IoE) has resulted in growing interest in the millimeter wave (mmW) spectrum above 24GHz and as high as 300GHz. This massive amount of bandwidth is now known as the 5G spectrum.
Any practical use of mmW frequencies for distances over a few meters will require beamforming and beamsteering. For 5G wireless communications, beamforming is necessary to overcome free-space path loss and provide narrow beams to mitigate co-user interference. The IoE will rely on 5G mmW beamforming for wireless power delivery and synchronization of various sensors.
Within an environment where heavy data usage is anticipated (e.g. urban, stadium), a dense deployment of small cells will be necessary. In turn, future small cells should be comparable in price to a wifi router. To reach such a low price point, it will be necessary to move the complexity of a phased array system into a standard CMOS platform.
In this work we propose a 28GHz small cell, which will provide >1Gbps down link data rates to mobile users at distances up to 150m. The proposed system will utilize hybrid beamforming in order to simultaneously generate multiple beams achieving aggregate data rates >4Gbps.
As a proof of concept we are developing a 28GHz 4-channel transmit beamformer in a 40nm CMOS process. The proposed beamformer will be the core building block of a 64-element sub-array.
Advanced Fabrication Techniques for Ubiquitous Radio-Frequency Devices in the Internet of Everything
The current interest in home, environmental, industrial, and urban monitoring places a unique burden on radio-frequency devices. In order for the Internet of Everything to be truly enabled, we envision ubiquitous devices that must be deployable without severely compromising the user's experience and daily activities. As such, we are utilizing novel fabrication methods and materials as well as structural designs to create antennas and radio-frequency devices with nonconventional properties. Some of these properties include stretchability, conformability, and transparency, with which we can realize electromagnetic reconfigurability or sensing and also invisible devices. This project is done in collaboration with the Applied Nanophotonics Laboratory led by Professor Jonathan Fan.
Large-scale Millimeter-wave Arrays for the Internet of Everything
The exorbitant cost of existing phased array antennas has limited their use to mainly military and high-value commercial applications. This project aims to make phased arrays and their incredible potential available to applications with consumer-grade budgets using innovative architectures and integrated CMOS electronics. Applications that would benefit from low cost phased arrays include advanced radars for autonomous cars and small UAVs, LEO satellite or solar airplane based Internet services, and even wireless power delivery using spotlight-like RF beams. Current work focuses on building large scale arrays cost-effectively by shoehorning commercial, off the shelf components into use as millimeter wave devices.