Integrated Packaging Design of Low-Cost Bondwire Interconnection for 60-GHz CMOS Vital-Signs Radar Sensor Chip With Millimeter-Wave Planar Antenna

This paper presents a compact integration design of a low-cost bondwire-interconnection scheme between a 60-GHz CMOS vital-signs Doppler radar sensor chip and a millimeterwave patch-array planar antenna (17-dBi gain). The interconnection has the form of an inductance-capacitance-inductance structure configured as a T-matching network. It consists of a short microstrip line as a small capacitance and parallel bondwires as inductance. Open-ended stubs are additionally applied in the design to improve the ground connection at 60 GHz. To enhance the robustness of the impedance-matching bandwidth to withstand possible bonding length variations, additional series and shunt transmission lines are also deployed. The proposed low-cost integrated circuit-to-board interconnection design requires no additional processing (e.g., cavity etching of the carrier board). In the experimental measurement, compared with the radar sensor connected with a 7-dB-loss V-band cable to the planar antenna in a previous report, the implemented compact bondwire-interconnected CMOS radar antenna module can enhance the detection range from 75 to at least 105 cm [and potentially up to 120-150 cm if the radar chip output power (0 dBm) is the same as 3 dBm]. This shows the potential facilitation for the incorporation of the 60-GHz radar sensor chip into portable devices for wireless remote physiological monitoring healthcare applications.