A medium-gain Grid Array Antenna (GAA) is developed and manufactured in ESL41110, a low εr Low Temperature Co-fired Ceramics (LTCC) from ElectroScience Laboratory. The antenna dimensions are 12 mm × 12 mm × 0.3 mm and it has a measured impedance bandwidth from 135 to 142 GHz, with a boresight maximum gain of 7.96 dBi and vertical beams. In order to realize this antenna, new LTCC fabrication steps had to be developed and qualified in the in-house procedure, including laser ablation of gold in the green state as well as after sintering.