Helton SILVA BERNARDO

Abstract: The objective of the thesis is to propose some technical breakthroughs in the distributed amplification domain and to provide innovative solutions to the current blocking points in order to achieve, in CMOS technology, a band-gain product per unit of consumption and surface area of 20 GHz/mW.mm², that is to say equivalent to that obtained by a bipolar circuit. This project will rely on the performances offered by STMicroelectronics' 55nm BiCMOS technology with the aim of promoting this technology.
Breakthroughs could be summarized in 3 bullets:
•    Technology: The more advanced the technological node in silicon, the more the transistors will be capable of providing gain at high frequency but the higher will be the surface cost. The same observation is made when using III-V technologies naturally suitable to millimeter waves. Meanwhile, distributed amplification is inherently bulky. It is thus a key point to reduce the silicon surface area with smart architectures whilst keeping the same electrical performance.
•    Consumption: Resistive losses at high frequency (skin effect in particular) impact the gain level, compensated by an additional DC power supply. It is the Product-Gain-Band/DC Consumption factor of merit which is then important: FoM=GBP⁄Pdc. Technologies to address high FoM are often the most expensive.
•    Millimeter-wave expertise: The design of a distributed amplifier is not complicated but complex and requires experience, expertise, design and test tools adapted to millimeter-wave frequencies. TIMA has the expertise and access to design and test tools. The candidate will gain experience and skills in the field of millimeter-waves at the end of her.his three years of doctorate.