Bandwidth enhancement of coaxial line to post-wall waveguide transition using short-ended straight post in 60-GHz band

We have applied the bandwidth-enhancement technique to a transition between coaxial line and post-wall waveguide with a short-ended straight post. The straight post connected to the coaxial line works for not only impedance matching for input coaxial port but also impedance inverter between two cavities. The dual resonance behavior of the transition was confirmed by numerical studies. Using our bandwidth-enhancement technique, a transition with straight short-ended post was successfully designed for the waveguide slot-array antenna at 60 GHz. It can be concluded from our designed transition that the effectiveness of our bandwidth enhancement technique is verified.