This contribution presents the fabrication and measurements of the leaky lens antenna integrated with a cryogenically cooled Kinetic Inductance Detector, in order to achieve an ultra sensitive THz receivers over a bandwidth ranging from 0.15 GHz to 1.5 THz. The system has been manufactured and characterized in terms of power efficiency, and radiation pattern properties. The agreement between the expectations and the measurements is excellent already at this first attempt. These measurements demonstrate the manufacturability and repeatability at THz frequencies of the properties of the leaky lens antenna concept.