A Low-Power High-Gain Low Noise Amplifier For Wake-Up Receivers

Abstract

The recent researches are focus on the ultra-low power system like bio-medical device and IoT/IoE devices. In this case, the Wake-Up Receiver (WuRx) is absolutely necessary to make connections between devices with ultra-low power consumption. In the WuRx, the most important block is the Low-Noise Amplifier (LNA). The purpose of LNA in the WuRx is to ensure an accurate communication and reduce overall system power consumption between devices by performing several roles simultaneously on single stage like high gain and low noise and so on. This thesis presents the design of LNA for input stage of WuRx. For low power WuRx architecture, the differential output of tunable high gain, low noise figure, input/output isolation, differential output gain-phase balancing, good linearity, and low power are needed simultaneously. The pseudo-differential LNA incorporates an active single-to-differential conversion. By utilizing Q-enhancement circuit with LC tank at output nodes of pseudo-differential topology, the LNA has a tunable ultra-high gain. And, the both input/output isolation and differential output gain-phase balancing can be achieved by using capacitive cross-coupled technique. We described the bootstrapping capacitor for noise filtering effect in the pseudo-input stage. A 2.4GHz LNA design optimized in a 90nm CMOS process shows that the tolerable differential output gain-phase imbalances are up to 0.08dB and 0.1°, respectively. And, the simulation results show that proposed LNA achieves a noise figure of 4.7 to 5.7dB, and an IIP3 of -26.9dBm to -63.5dBm at the 2.4GHz according to the tunable current of Q-enhancement for obtaining variable gain of 26dB to 56dB with just 90 to 169μA current consumption, and 1V supply voltage. ⓒ 2017 DGIST