Power Optimization of LNA for LTE Receiver

Abstract

In the up-coming wireless standards, focus is not only for improving the quality of service but also towards finding the integrated solution for all the existing standards. In this regard, system-on-chip (SOC) must have the ability to process multi-mode and multi-band signals without any relaxation in their energy consumption. Hence in circuit realization, transceivers' SOCs may require multiple LNAs (low-noise amplifier), key component of receiver, where the power requirement of individual amplifier is critical in-order to elongate the battery life. In this paper, the power of LNA is optimized based on the sensitivity requirement of the receiver. Accordingly, the LTE receiver performance assessment is carried out to find the maximum noise limitation of the LNA. For meeting the receiver noise performance, a sub-threshold LNA is implemented that consumes a total power of 706 uW with an affordable 2 dB noise figure (NF). The resulting LNA is implemented in 65nm technology and it is compensated against process variations. The low power LNA achieves about S21 of 12.9 dB in typical corner case and undergoes only a maximum change around +/-3.4% when all the corners are considered. Comparison with other microwatt LNAs, shows that presented amplifier offers the best NF with a moderate figure of merit (FOM).