Design and performance of log-periodic substrate integrated waveguide slot antennas

Substrate integrated waveguide (SIW) technology is combined with the classical theory of log-periodic antennas to realize SIW slot antennas with broadband performance. Based on the orientation of the slots, two variations are compared - the transverse slot antenna and longitudinal slot antenna. Both techniques achieve much wider impedance bandwidth than a traditional uniform slotted waveguide antenna and a useful radiation pattern is maintained over a 4 GHz bandwidth. Two prototypes, centered at 15 and 24 GHz, have been fabricated and measured to verify the simulations.