Diamond as an insulating heat sink for a series combination of IMPATT diodes

Series connections of IMPATT diodes are capable of giving high microwave power output at a reasonably high impedance level. The series combination avoids many of the stability problems associated with parallel combinations. A series combination of three diodes mounted on a diamond heat sink produced a C3V 13-GHz output of 4.5 watts with an efficiency of 6.4 percent.