A W-Band Integrated Tapered Array Antenna With Series Feed for Noncontact Vital Sign Detection

Abstract

A <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$W$ </tex-math></inline-formula> -band integrated tapered array antenna with series feed is presented. To reduce the fabrication cost, the antenna is designed on a single layer with the standard printed circuit board (PCB) process. In the array design, a novel coplanar waveguide (CPW) feeding structure is proposed to simplify the feeding network and fabrication by avoiding three-way power divider and via process. Considering the interconnection reliability and cost, the wire-bonding technique is used to connect the integrated circuit (IC) and antenna. To compensate for the parasitic effect of the bond wire and enhance the bandwidth of the antenna with interconnection, an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCL</i> compensation structure is introduced and codesigned with the array antenna, achieving wideband-impedance feature. To demonstrate the validity of the design, several prototypes of the proposed antennas are implemented and measured. The measured results show that the array antenna with wire-bonding interconnection achieves a fractional impedance bandwidth ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\vert S_{11}\vert &lt; -10$ </tex-math></inline-formula> dB) of 13.2%, sidelobe level less than −15 dB at 100 GHz, and ~15 dBi gain. The simulated radiation efficiency is larger than 80% from 98 to 104 GHz. With our designed 100 GHz CMOS radar transceiver, the proposed antenna is used to detect the human vital sign.