A 77–81-GHz 16-Element Phased-Array Receiver With $\pm {\hbox{50}}^{\circ}$ Beam Scanning for Advanced Automotive Radars

A 16-element phased-array receiver has been developed for advanced W-band automotive radars. The phased-array receiver is based on a single SiGe chip with RF beamforming capabilities, which is packaged using low-cost bond-wire techniques and attached to a 16-element linear microstrip array. The antenna results in a directivity of 29.3 dB and a gain of 28.0 dB at 77–81 GHz, and can be scanned to
$\pm {\hbox{50}}^{\circ}$
in the azimuth plane in
$\sim {\hbox {1}}^{\circ}$
steps. The packaging details are presented together with the steps taken to ensure a wideband impedance match and low coupling between the phased-array channels. Gain measurements done at 79 GHz agree well with simulations. The 16-element phased array receiver was used with a 2-element frequency-modulated continuous-wave transmitter at 76.5–77 GHz and high-resolution millimeter-wave images were obtained. The work shows that complex millimeter-wave phased arrays can be packaged using traditional bond-wire techniques, and can be a powerful solution for advanced automotive radars.