Characterization of a 90° microstrip bend with arbitrary mitervia the time-domain finite difference method

A 90° microstrip bend with an arbitrary miter is characterized using the finite difference time-domain (FDTD) method. In this method, to simplify computations, the microstrip structure is enclosed by four electric walls; thus radiation effects are neglected. Time histories generated by FDTD techniques are Fourier-transformed to yield broadband scattering parameters of the microstrip bend. A miter is introduced to improve the transmission characteristics of the bend, and an optimal miter length is found such that the reflection from the microstrip bend over a broad frequency range is minimized