What's the difference between the "harmonic propagation" and "scattered harmonic propagation"?

Dear all:
IN the RF => In plane wave model ,What's the difference between the "harmonic propagation" and "scattered harmonic propagation"?

Q2. if I set the square and draw the rectangle around the square with PML condition and

set the pair on one side , then I can't evaluate any point by using the "point evaluation"?

(file as QQQ.m)


Q3.IN "scattered" harmonic propagation , the same condition IN Q2 ,

plot the scattered field z component , it is different in Q2, how to explain it?

(file as SSS.m)

THANK YOU ALL,

Best regards you-che he