Antenna Arrays in the mm-Wave Band

In this talk, we present a novel, low-profile, high-efficiency, tightly-coupled, conformal phased-array topology that can be directly fabricated onto transceiver chips using conventional lithographic fabrication methods. The prototype array is based on Munk’s current sheet array (CSA) concept, which achieves wideband operation, covering entire 30-70 GHz. Furthermore, the radiating elements are well-isolated from the transceiver substrate by a ground plate, resulting in computed radiation efficiencies more than 60% over the entire impedance bandwidth. A 9-element (3×3) phased array prototype consisting of 8 metal and dielectric layers are patterned on a Si substrate using SU-8 as the substrate material. On a 4-inch Si test wafer, it is possible to fabricate 48 such array in one lithography cycle as each array is approximately 7mm×3mm in lateral size and only 500 microns thick. We will present the design details and characterization results, along with key challenges we faced in fabricating and testing this new class of on-wafer mmW phased arrays.