ECE PhD Prospectus Defense: Xinchang Zhang

ECE PhD Prospectus Defense: Xinchang Zhang

Title: Efficient mmWave-to-Optical Signal Conversion for Analog Photonic Links: Enabling Large-Scale RF Phased Arrays and Massive MIMO 6G Communication Systems

Presenter: Xinchang Zhang

Advisor: Professor Milos Popovic

Chair: Professor Roberto Paiella

Committee: Professor Milos Popovic, Professor Roberto Paiella, Professor Tianyu Wang

Google Scholar Profile: https://scholar.google.com/citations?hl=en&user=9fIvuNIAAAAJ&view_op=list_works&sortby=pubdate

Abstract: 6G communication systems using millimetre-wave carriers embrace the scalable massive-MIMO architecture to increase the data bandwidth. The state-of-the-art technologies face the difficulties of size, weight, power and cost (SWAP-C) limitations when scaling up the data capacity. In this work, an analog photonic link based optical interconnect chiplet solution is proposed to address this SWAP-C challenge. The proposed method opens up the possibility to disaggregate of power-hungry stages and components from the antenna array and allows remote signal processing.

A mm-wave to optical signal converter on a monolithic integration platform has been designed to be co-packaged with radio units in an antenna array. The proposed converter contains an on-chip mm-wave signal power amplifier and a cascaded multi-cavity electro-optical modulator based on photonic molecules. The converted mm-wave signal can be transmitted in optical domain through fibres to the processing chips beyond the antenna board.

In this report, a theory model of triple-cavity modulator that enables broadband mmwave frequency application is discussed and its performance comparison with other photonic molecule devices is performed. Preliminary results of mm-wave to optical signal conversion are demonstrated to show a promising performance metric for optical link demonstration.

The proposed future work contains three phases. The demonstration of high efficiency conversion from mm-wave to optical domain will be the first stage, followed by the characterizations of the converted signal as a new optical tone in frequency domain. A single frequency channel analog photonic link transmitting data stream will be the next step of investigation. Further, a wavelength division multiplexing simultaneously allowing four independent mm-wave to optical converter will be designed to demonstrate a two-by-two disaggregated radio unit array.