Planar antipodal linearly tapered slot antenna using grounded coplanar waveguide-to-substrate integrated waveguide transition for passive millimeter-wave imaging

In this work, a novel antipodal linearly tapered slot antenna (ALTSA) with two types of grounded coplanar waveguide (GCPW)-to-substrate integrated waveguide (SIW) transitions are proposed and demonstrated. The antenna is well designed for using as a feed antenna in the focal plane array (FPA) imaging system. PCB technology is used to fabricate the SIW antenna in a single layer structure. Good agreement was obtained between the simulation and measurement results. The return loss of the proposed antenna can achieve below -13dB at Ka-band, meanwhile, the E-plane side lobe is almost 15dB down. When placed on the focal plane of a reflector antenna, its side lobe dropped to 40dB down, which shows its high suitability for passive millimeter-wave (PMMW) FPA imaging system.