2-D Quasi-Optical Power Combining Oscillator Array at D-Band

A millimeter-wave quasi-optical power combiner for a two-dimensional active array is experimentally investigated at 150 GHz. The combiner consists of a transmitting rectangular horn antenna array, a dual-offset reflector setup, and a receiving antenna equal in dimensions with respect to the transmitting antennas. Both reflectors are paraboloids with superimposed surface reliefs to efficiently couple the transmitted wave into the receiving antenna. The superimposed surface profiles are computer-generated and match the transformed field, calculated under the physical optics approximation, to the receiving antenna aperture field. To demonstrate the feasibility of this concept even for large inter-element spacings, experiments were carried out for a 2D IMPATT-oscillator combiner at 150 GHz