A 52dB spurious-free dynamic range Ku-band LNA-mixer in a 130nm SiGe BiCMOS process

This work presents a high-linearity, low noise figure, Ku-band (12 to 18 GHz) LNA-Mixer front-end block in a 130 nm SiGe BiCMOS process. A tuned transformer converts the single-ended output of the LNA to a differential signal at its secondary which is coupled directly to the tail nodes of the switching pairs of the Gilbert mixer. The LNA output sees a low impedance, and hence a low output voltage swing. This along with the absence of the extra trans-conductance stage in the mixer enhances its linearity. The measured gain, noise figure, and IIP3 at 16 GHz input are 12 dB, 4 dB, and 4 dBm. This gives a spurious-free dynamic range of 52 dB in a 4 GHz bandwidth. The chip consumes 272 mW and occupies 1 mm2