Microstrip-to-Waveguide Transition for 3D-Printed mm-Wave Sectoral Horn Array

This paper discusses a novel PCB transition to feed an H-plane sectoral horn array intended for use with highly integrated mm-wave beamforming devices. To maintain the half-wavelength element spacing necessary for grating-lobe free operation, the signal launch into rectangular waveguide is oriented such that the waveguide ‘b’ dimension aligns with the PCB edge. The fabricated design achieves a good impedance match over a 14 GHz bandwidth centred at 64 GHz.