Implementation of a Low-Power Folded-Cascode RF Front-End for LTE Receivers

Abstract

This paper develop a 2.6-GHz receiver RF front-end for 3GPP LTE system. Digital Low-IF technique has been chosen as the receiver architecture. The RF front-end includes differential source inductor degeneration LNA and folded-cascode mixer. Due to the LTE system is applied to portable device, to achieve low power consumption issue, all of the LNA transistors are biased in sub threshold region, which can offer superior gain per current consumption. With power-constrained simultaneous noise and input matching (PCSNIM) technique, the input matching design of LNA become more flexible and still have good noise performance at low power consumption situation. One of advantages of folded-cascode mixer is implemented using PMOS device as switching stage for lower flicker noise than NMOS. Another advantage is that the LNA stage and the switching stage are separated in DC biasing such as the switching stage can operates in much lower dc current as compared to the LNA stage for less noise contributed at output. The circuit operated under a supply voltage of 1.2 V and current consumption of 2.27 mA. According to measurement results, the RF front-end achieves 12 dB conversion gain with P1dB of -9 dBm and IIP3 of -4.04 dBm.