A 1–50 GHz dielectric spectroscopy biosensor with integrated receiver front-end in 65nm CMOS

In this paper, an on-chip transmission-line sensor with integrated receiver front-end implemented in 65nm CMOS facilitates the measurement of complex permittivity from 1 to 50 GHz for liquid samples. A robust extraction model allows accurate prediction of sample permittivity based on reference liquid calibration and eases the design of the hardware. Front-end circuits include a 60 GHz distributed amplifier with noise-cancellation active termination to improve the noise figure below 18 GHz. Correlated-double-sampling technique is used in the measurement setup to reject system phase drift. The sensor achieves 1% permittivity sensitivity at 20 GHz through liquid measurements with a minimum sensing volume of 0.09 nL. The prototype chip consumes a total power of 114 mW.