H. Klingbeil et al., FINITE-DIFFERENCE ANALYSIS OF STRUCTURES CONSISTING OF ROUNDLY AND RECTANGULARLY SHAPED DOMAINS, IEEE microwave and guided wave letters, 6(8), 1996, pp. 295-297
A new method is presented that allows the analysis of a combination of
both circularly and rectangularly shaped subdomains in the same struc
ture, The method is based on the use of polygonal grids in connection
with the finite-difference method in the frequency domain, The converg
ence behavior of this new efficient algorithm is analyzed and compared
to conventional stair-case approximations for a circular waveguide. F
inally, the dispersion characteristic of a square waveguide with a cir
cular dielectric rod is presented.