Wideband D-Band Antenna Array Co-Designed With Wirebonded Power Amplifier on a PCB Carrier

Abstract

The co-design, fabrication, and characterization of an active D-band antenna array with large bandwidth for use in next-generation, high-speed wireless systems are presented. A silicon-germanium BiCMOS D-band power amplifier (PA) is compactly integrated on the backside of a printed-circuit-board (PCB)-based 4 x 1 antenna array with a vertical substrate-integrated-waveguide-based corporate feed network, minimizing its impact on the array's radiation pattern, while keeping the array width below lambda/2. This co-design is performed by employing a tailored wirebonding process to minimize interconnect loss and by optimizing the antenna array's input impedance to maximize the PA's peak output power. The former is achieved by thinning the integrated circuit (IC) and embedding it into a milled cavity in the PCB carrier, thereby leveling the IC and PCB surfaces to minimize the bond wire length. To attain the latter, a grounded coplanar waveguide-to-substrate-integrated-waveguide transition is proposed to tailor the antenna input impedance and compensate for the remaining effects of the bond wires. After assembly, the active antenna array is characterized in terms of gain, bandwidth, and equivalent isotropic radiated power (EIRP). The module features a peak combined gain of 26 dBi over a 3 dB gain bandwidth of 23 GHz and a maximum EIRP of 22.8 dBm with a 25 GHz EIRP bandwidth.