A low power 2.4 GHz quadrature local oscillator buffer for Bluetooth low energy applications

Abstract

In this paper, a low power 2.4 GHz quadrature local oscillator (LO) buffer for Bluetooth low energy applications is proposed. A proposed quadrature LO buffer employs the transconductor-type IQ quadrature generator with a gain/phase mismatch compensator and generates accurate quadrature signals at the 2.4 GHz frequency with parasitic capacitances. The proposed LO buffer can minimize the power consumption of the LO path because the block generating quadrature signals such as a divider-by-2, a poly-phase filter, and a quadrature VCO can be removed from the LO path. The prototype is realized in CMOS 65 nm process. The LO buffer achieves simulated voltage gain of 6.5 dB and generates accurate quadrature signals while consuming 2 mA at the supply voltage of 1 V.