In this paper, a new family of Cassinian wave-guides

is proposed, simulating and calculation are finished with CST

Microwave Studio that based on Finite Integral Technique (FIT),

and some results are given. Electromagnetic field mode type of it

is TE, electromagnetic field is stronger near neck region, and

some resonance frequencies appear. The new Cassinian curve

wave-guides will possess higher power than ones of the

rectangular and elliptic wave-guides because the height at the

position where maximal electric field occurs is smaller.