A Ge backward detector diode with a low temperature coefficient at X-band

Many new microwave systems need detector diodes with large differential sensitivity, low change of output voltage with ambient temperature, low noise, and long-term stability. An alloyed junction (pulse-bonded) germanium backward diode has been developed which is superior to point-contact detector diodes for these applications. This diode has a differential sensitivity of 8 mV/db with an average output voltage of 60 mV into a 100 ohm load, and a temperature coefficient of 9 µV/°C with an input power of -4 dbm at 11 Gc/s. Noise measurements indicate this diode has about 20 db less 1/f noise than point-contact diodes. The diode has a junction capacitance of about 0.1 pf, a negative resistance of 1000 ohms and a series resistance of 8 ohms.