From Microwatt to Gigabit: Challenges of Modern Radio Design

On the brink of introducing the fifth generation (5G) of cellular networks, the art of radio-frequency (RF) integrated circuit design has never seen such a wide spread of diverging requirements: On the one hand, ubiquitous sensor networks are mandating power budgets in the order of micro-watt. They should be constructed as energy-autonomous, wireless, low-cost sensor nodes. This demand is caused by massive deployment scenarios of billions of devices, which makes wires and batteries unpractical. As a result, the desire for the radio nodes to harvest their operational energy from the environment emerges. On the other hand, the recent and ongoing realization of gigabit-per-second capable cellular modems is driving hardware and power requirements to extremes. To overcome hardware limitations, introduced by analog impairments, digital correction and alignment algorithms are employed for compensation. These factors call for usage of expensive advanced CMOS technology nodes and increased utilization of digital signal processing techniques. In this paper, we recap ongoing trends and developments for ultra-low power and high-end transceiver (TRX) designs using CMOS technology nodes ranging from low-cost to highest performance.