A 0.62–10GHz CMOS dielectric spectroscopy system for chemical/biological material characterization

A CMOS wideband dielectric spectroscopy system is proposed for chemical and biological material characterization. The complex permittivity detection is performed using a configurable harmonic-rejecting receiver capable of indirectly measuring the complex admittance of sensing capacitor exposed to the material-under-test (MUT) and subject to RF signal excitation with a frequency range of 0.62-10GHz. The sensing capacitor is embedded in a voltage divider topology with a fixed capacitor and the relative variations in the magnitude and phase of the voltages across the capacitors are used to find the real and imaginary parts of the permittivity. The sensor achieves an rms permittivity error of less than 1% over the entire operation bandwidth.