Planar high-gain antipodal linearly tapered slot antenna for passive millimeter-wave focal plane array imaging

In this work, a novel antipodal linearly tapered slot antenna (ALTSA) using microstrip-to-substrate integrated waveguide (SIW) transition is proposed and demonstrated. The antenna is well designed for use as a feed antenna in an 8mm focal plane array (FPA) imaging system. SIW feeding system is used for its salient features for microwave and millimeter-wave applications, including low-cost fabrication. PCB technology is used to fabricate the SIW antenna in a single layer structure. The fabricated antenna was measured and good agreement was obtained between the simulation and measurement results. The S11 of the proposed antenna is below -12dB over the Ka-band, meanwhile, the E-plane side lobe is almost 14dB down. The feed antenna was placed on the focal plane of a reflector antenna and its side lobe level drops to 40dB down, which shows us its high suitability for passive millimeter-wave (PMMW) focal plane array imaging systems.