Low-Power CMOS RF front-end for non-coherent IR-UWB receiver

This paper presents a low-power CMOS RF front-end for 3-5 GHz non-coherent impulse-radio ultra-wideband (IR-UWB) receiver. The proposed front-end comprises a variable-gain low noise amplifier (VG-LNA), an active balun and an analog squarer. Current reuse topology has been adopted in both VG-LNA and active balun to reduce the power consumption. The squarer design is based on the quadratic law of MOSFET in saturation and the performance is optimized for 3-5 GHz UWB signal detection using cascode stage and active load. The VG-LNA has a measured maximum voltage gain of 33 dB/12 dB for high/low gain modes with minimum noise figure 3.7 dB/4.2 dB respectively. Measurements show that the proposed RF front-end achieves an input sensitivity of -91 dBm for UWB on-off keying (OOK) input signal at 1 Mbps pulse rate with an energy efficiency of 3.1 nJ/bit.