Inductorless Design of Wireless CMOS Frontends

Inductors are used in RF design to extend the bandwidth by resonating out the load and/or parasitic capacitance. However, on-chip inductors are large and cannot be ported easily from one process to the next. Due to modern CMOS scaling, inductorless RF design is becoming possible. In this paper we describe a new methodology for designing the RF frontends necessary for the UWB 3.1GHz-10.6GHz bandwidth in a 0.13μm CMOS technology. To validate our design methodology two receiver RF frontends were designed; a traditional inductor based design and an inductorless design. A common-gate LNA transconductor is followed by a capacitive peaking LNA-mixer pair (CPLM). Simulation results show that a CPLM with the same bandwidth has better linearity, comparable noise figure and uses only 17% more power. The silicon area savings for the inductorless LNA and I/Q mixers is roughly 90% in comparison to traditional inductor based designs [1] illustrating its compact size and improved portability.