Populärvetenskap
Siyu Tan, Postdoktor
Technology advancements in the 21st century create a vast amount of possibilities, allowing us to make strides that our ancestors could only dream of. Communication systems improve vastly in the past several decades. The development of these systems closely following the evolution of Cellular mobile network standards since the early 1990s to the latest commercialized 5G, the fifth generation that starts deploying in 2019. The emerging 5G communication systems target reliable connections with significantly reduced latency at increased transmission speed. Communication among people is not limited to voice-only anymore but extended to more versatile formats such as video chatting and multimedia messages. It is already an essential part of our daily lives that communications among us are through smart devices besides face-to-face.
Nowadays, the rapid development of high-performance handheld devices facilitates fast and secure access to the Internet, a global system that connects people worldwide. We share lives, acquire new knowledge, learn history, and explore the world without leaving home, by simply surfing the Internet. The ever increased demands of smooth surfing experiences increase the current communication systems' pressure and bring up the stringent requirements for technology advancement of next-generation communication devices. They prefer low latency, stable and fast upload/download transmission speed, and broad coverage with low energy dissipation.
The advance of communication systems will not be successful without high-performance analog to digital converters (ADC), which are essential components in modern high-performance radio transceiver device. The ADC acts as a bridge connecting the analog and the digital domain. Usually, the analog domain signals are real-world measurable physical quantities, such as voltage or current. However, the high-performance processors are entirely digital and only capable of processing signals in the digital format.
High-performance ADCs are capable of immediately digitalizing the analog signal at high speed. A high-speed ADC coping with a high-speed digital processor can digitalize the input analog signals and filter, calibrate them in the digital domain real-time. It allows the very flexible, reliable, and high power-efficient digital signal processing. All the great features are possible thanks to the continuous shrinking of Complementary Metal Oxide Semiconductor (CMOS) technology nodes in integrated circuits.
The main focus of this research work is designing high-performance ADCs on integrated circuits. This work discusses the ADC architectures and their circuit-level implementations in advanced CMOS technologies. This research aims to find an optimized design for high-speed analog to digital conversion, to understand their benefits and limitations, and to evaluate the possibilities of placing them inside large base station devices in the future.