) On surface BC: c) On surface CD H&=HCD=O d) On surface AD HL=HAO=O 3.4.2 Formulation of the Muiüpk Difhction T om Sinœ multiple diffraction is considered here (refer to Figure 3.23), the folldng definitions apply: HM= Sum of ail multiple d-iffractions due to al1 dg- of the rectangular cylinder amving at A from the B direction. Hm= Surn of al1 multiple dimactions due to al1 edgas of the rectangutar cylinder arriving at A fmm the D direction. Hm Ha Hffi Hffi Ha and Hm have similar definitions depending on the edge. - e -Ih*x Kx- - m is the diameter of cylinder in x axis. 6' -Ihy 6-L J;;;; , wy is the diameter of cyiinder in the y axis.
To find the multiple difhaction terms, a set of limr equations must be sdvd: