A high linear upconversion mixer and VCO design using fully integrated current injection technique

An InGaP/GaAs HBT upconversion mixer and VCO is designed by current injection and harmonic noise frequency filtering technique to improve linearity and phase noise performance. The VCO which is combined with mixer, is designed and fabricated with low phase noise of -133.96 dBc/Hz at 1 MHz offset. Since VCO output and mixer input impedances are matched to 50Omega, there is no need an extra matching circuit. The measured conversion gain of the upconversion mixer is 0 dB. It shows the effective gain flatness of 1.2 dB from 1.6 GHz to 1.8 GHz. Also, it has third-order input intercept point (IIP3) of +18 dBm, and a third-order output intercept point (OIP3) of +19.2 dBm. An integrated differential cascode output amplifier generates the input and output-referred 1-dB compression point (PldB) as 1 dBm and 1.2 dBm. The high linearity mixer-VCO is fabricated within a total chip area of 2560 x 900 mum.