By Robert Boczkiewicz and John Shiffman DENVER (Reuters) – A Chinese citizen convicted of trying to smuggle American-made radiation-hardened microchips from California to China was sentenced Wednesday to three years in U.S. prison. Philip Chaohui He, the target of a U.S. Homeland Security sting, was arrested in late 2011 at a port near Los Angeles as he approached a Chinese freighter. In his car trunk, agents found 200 radiation-hardened microchips hidden inside a tub of baby formula. U.S. officials report a recent spike in efforts by the Chinese government to obtain the specialized, American-made microchips, which are critical for operating satellites and ballistic missiles, as well as protecting military hardware from solar and nuclear radiation.