Thermography represents a useful in-service inspection technique for c
arbon fiber-reinforced composite structures. Conventional heat loading
by optical radiation suffers from dazzling the thermal imaging system
and thermal artifacts possibly arising from variations in optical abs
orptance of the paints used for coloring the structure. Microwave radi
ation can overcome these disadvantages. It has been proved that the se
lection Of millimeter wave frequencies gives sufficient heat to accomp
lish one-sided thermographic testing irrespective of the (dielectric)
coat of paint. Experimental results of the heating efficiency were sho
wn for woven and multidirectional carbon fiber-reinforced epoxy lamina
tes. Inspection performance was demonstrated by the detection of a bar
ely visible impact damage.