Prepregs and laminates having homogeneous dielectric properties

A prepreg comprising:

• an at least partially cured resin impregnated reinforcing material portion having a dielectric constant DkWR, comprising reinforcing material and a resin, where the reinforcing material has a dielectric constant DkR prior to the resin impregnation;
• and
• a free resin portion having a dielectric constant DkW,
• wherein the resin includes at least one high dielectric constant material, which is incorporated into the resin in an amount sufficient to match the DkWR with the DkW such that the DkWR and DkW differ by no more than (±) 15%, and wherein the dielectric constant DkW and the dielectric constant DkR differ by more than 15%.