A Low-Voltage Fully-Integrated 5GHz Low Noise Amplifier in 0.18μm CMOS

A 5GHz Low Noise Amplifier (LNA) is presented using the folded-cascode topology which is suitable for low-voltage Radio Frequency Identification (RFID) applications. It employs both NMOS and PMOS devices to reduce the required supply voltage to less than 1V. The circuit is fully integrated on-chip, with inductors implemented using stacked spirals to save space. It is experimentally demonstrated in 0.18μm CMOS and performs particularly well at 5GHz, with the noise figure being below 3dB. The gain and input 1dB compression point exceed 12dB and -11.5dBm respectively, while the input return loss is better than -20dB. The LNA has an active footprint of only 575μm by 525μm, and consumes less than 10mW from a 1V supply.