A low-power 2.4-GHz combined LNA-VCO structure in 0.13-μm CMOS

A combined low-noise amplifier and voltage-controlled oscillator (LNA-VCO)is designed and laid-out in a 0.13-μm CMOS technology. The low-power LC VCO and LNA circuits are stacked and share the same bias current. An LC filter is used between the LNA and the VCO to improve the phase noise performance of the VCO. Based on post-layout simulations, the LNA achieves a gain of 17.7 dB and a noise figure of 5.1 dB at 2.4 GHz. The VCO has a center frequency of 2.45 GHz with a 370 mV output swing and a phase noise of -111 dBc/Hz at 1-MHz offset. The LNA-VCO consumes 124 μW from a 0.8 V supply.