A 12×16-element corporate-feed slot array is presented. The corporate-feed circuit for the 12×16-elemtent array consists of cross-junctions and asymmetric T-junctions, whereas the conventional one is limited to arrays of 2m×2n slots by its use of symmetric T-junctions. Simulations of the 12×16-element array show a 7.6% bandwidth for reflection less than -14dB. A 31.7-dBi gain with an antenna efficiency of 82.6% is obtained at the design frequency of 61.5GHz. The 12×16-element array is fabricated by diffusion bonding of laminated thin metal plates. Measurements indicate 31.1-dBi gain with 71.9% antenna efficiency at 61.5GHz.