HIGH POWER VARACTOR DIODE.
Final rept., 15 Apr 61-28 Feb 63,
MICROWAVE ASSOCIATES INC BURLINGTON MASS
Pagination or Media Count:
Improvement of power dissipation of a ilicon varactor diode is discussed. The increase in power dissipation is obtained by modifying the fabrication techniques, and by using materials of higher thermal conductivity for the metal por tions of the diode package. A method of measur ing power dissipation is presented. This method is based on the principle that the forward drop of a diode varies with respect to temperature in a manner which is predictable and can be readily measured. Boron diffused epitaxial sili con material is used for the semiconductor ele ment. To obtain a frequency cutoff of 100kmc, it is necessary to use a maximum junction dia meter of 8 mils. The cutoff frequency is measured at 10 kmc using the reflectometer method. The reliability testing portion presents failure rate data on a number of varactor types and a point contact mixer diode. The data is derived from step-stress testing of these devices. Informa tion from temperature stress and dissipated power stress tests are presented. The correlation be tween these two types of stress when equivalent junction temperatures are considered is good. Temperature step-stress tests were repeated for a number of the varactor types following a re design of the diode package. Author