and since E~(=)=S then the contribution of tha scalar voitage potential to d~ the self terni is since A is small we can use the srmll argument approximation of JO and Y. from  and and by using Ji= J, and Y+Y1 we can mite Retaining terms of order x only (smll argumnt) resuits in Sinœ t = 24 + Z& $rom equations 2.30 and 2.42 Throughout this work the impeâance terms derived in this sedon will be useâ when applying moment method to a scattering problem.
In this chapter TG plane wavw are used to illuminate scattefers. UTD obtained surface current densiües are plotted for the infinite edges, strips and rectangular cylinders. The edge results are compareci with Sommer(iald9s solution. The strip and cylinder results are compared with the moment method rewh. 3.1 EOGE SURFACE CURENT USlNG UT0 To obtain the edge surface current density of Figure 2.1, we n d to calculate the total magnetic field on the surCace. Sinœ the wedge is a perfect electric conductor and aie incident plane wave is of the TG type, the magnetic field has only a z camponent and hence the cumnt density has a p component only, J =ixn. a) On the 'On side For a unity TEz plane wave irnpinging on the wedge at angle #a f z : QI, =g, and from equation 2.1 w e have & = $ +a from equation 2.4 Oh is the dithaction coefficient expanded in squation 2.5 +