Improved performance of IMPATT diodes fabricated from Ge

Recent results with germanium IMPATT diode oscillators are reported. Both n-p-i-p⁺and n-p structures have shown noise figures of 30 ± 1 dB when operated as amplifiers under high gain conditions in the 8 to 10 GHz range. This represents an approximate 10-dB improvement over comparable Si devices. Power outputs of 30 mW at 3 percent efficiency and 250 mW at 6 percent efficiency were measured for the n-p-i-p⁺and n-p structures, respectively.