Modelling of narrow microstrip lines using finite difference time domain method

The finite difference time domain technique is a much used method for the analysis of microstrip circuits. If, however, the strip widths are small, a fine mesh usually has to be used to resolve the geometrical detail. Static field solutions are used to reduce this constraint on the mesh and to allow a unit cell size which may be much greater than the strip width. It is shown that efficiency can be much improved while maintaining accuracy.