A 122 GHz Multiprobe Reflectometer for Dielectric Sensor Readout in SiGe BiCMOS Technology

In this publication a fully integrated multiprobe reflectometer at 122 GHz is presented. It can be used for readout of resonator-based dielectric sensors for measurement of chemical, biological, or medical liquids. The circuit consists of a voltage-controlled oscillator, an amplitude modulator, a capacitive tapped line, four power detectors, and a dummy sensor. The circuit is operated from a 3.75-V supply and has a power consumption of 319 mW. The readout principle of the circuit is demonstrated by comparing the S-parameters of the dummy sensor to measurements with a commercially available vector network analyzer. The circuit has been fabricated in a 190-GHz SiGe:C BiCMOS technology and occupies an area of 0.54 mm² .