High-Power Gunn Oscillator Diodes on Type-IIa Diamond Heat Sinks

Gallium arsenide Gunn diodes were mounted on a type-IIa diamond to reduce the thermal spreading resistance just under the wafer of the diodes. By using the diamond, the total thermal resistance of the diodes was reduced to half the usual resistance. A single-wafer Gunn diode on the type-IIa diamond produced 910 mW at 9.9 GHz with an efficiency of 3.1 percent.