A 14mA 2GHz 0.25 µm CMOS quadrature demodulator including a low phase noise local oscillator

A 2GHz quadrature demodulator in 0.25µm CMOS with low phase noise oscillator is presented. The system consumes less than 14mA from 2.5V supply and shows excellent performance: Low phase noise meeting triple band GSM specs, image rejection of more than 40dB, 11dBm mixer ilP3 and 0dBm CP, combined with a low noise figure of 7.2dB (DSB). The low power consumption is a consequence of avoiding any buffer in the quadrature LO generation. However, this requires the VCO frequency to double to 4GHz. An oscillator with a tuned microstrip resonator is proposed to overcome the limitation of integrated spiral inductors.