论文信息 - A Compact Energy Efficient CMOS Permittivity Sensor Based on Multiharmonic Downconversion and Tunable Impedance Bridge

A Compact Energy Efficient CMOS Permittivity Sensor Based on Multiharmonic Downconversion and Tunable Impedance Bridge

This paper presents a 0.15×0.3 mm2 complex permittivity sensor integrated in a 40-nm CMOS node. A single-ended patch, employed as a near-field sensing element, is integrated with a double-balanced, fully-differential tunable impedance bridge that is driven by a square RF pulse. The multi-harmonic, interme-diate-frequency down-conversion architecture achieves a compact form factor and fast multi-frequency readout. Measurement results show good agreement with theoretical values and the measured relative permittivity variation remains below 0.3 over a 0.1-10 GHz range at a 1-ms measurement time. The energy efficiency resulting from the fast measurement time and the record-small active area allows integration in battery-operated wearables.

[1] Michael A. Suster,et al. A Broadband Sensor Interface IC for Miniaturized Dielectric Spectroscopy From MHz to GHz , 2014, IEEE Journal of Solid-State Circuits.

[2] Michiel A. P. Pertijs,et al. A 40-nm CMOS permittivity sensor for chemical/biological material characterization at RF/microwave frequencies , 2016, 2016 IEEE MTT-S International Microwave Symposium (IMS).

[3] S. Barringer,et al. Dielectric Properties of Vegetables and Fruits as a Function of Temperature, Ash, and Moisture Content , 2003 .

[4] Ali M. Niknejad,et al. A 1–50 GHz dielectric spectroscopy biosensor with integrated receiver front-end in 65nm CMOS , 2013, 2013 IEEE MTT-S International Microwave Symposium Digest (MTT).