Design of the W-band smooth Gaussian radiator

In this paper, a smooth Gaussian radiator from a rectangular waveguide TE
10
mode to a circular waveguide HE
11
mode for W-band is proposed. The W-band smooth Gaussian radiator consists of two parts: one is to convert the TE
10
mode in the rectangular waveguide into the TE
11
mode in the circular waveguide using a square-circle transition; the other part is the TE
11
mode converted into a Gaussian distributed HE
11
mode using the waveguide wall smooth radius structure. The simulation results show that conversion efficiency of TE
10
-TE
11
is over 99.6% from the 84GHz-104GHz. The coupling efficiency of the TE
11
-HE
11
is more than 96% in the frequency range of
$92\text{GHz}\sim 98\text{GHz}$
. Meanwhile, the energy transmission efficiency can reach more than 98%. The smooth Gaussian radiator has a simple structure, easy to machine, and avoids the disadvantage of the corrugated Gaussian radiator.